Merge remote-tracking branch 'upstream/master' into pr/1702

148 files changed, 4826 insertions, 1589 deletions

diff --git a/examples/device/CMakeLists.txt b/examples/device/CMakeLists.txt
index edf5ab805..0a2e49ef0 100644
--- a/examples/device/CMakeLists.txt
+++ b/examples/device/CMakeLists.txt
@@ -1,20 +1,23 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../hw/bsp/family_support.cmake)
 
-project(tinyusb_device_examples)
+project(tinyusb_device_examples C CXX ASM)
 family_initialize_project(tinyusb_device_examples ${CMAKE_CURRENT_LIST_DIR})
 
 # family_add_subdirectory will filter what to actually add based on selected FAMILY
 family_add_subdirectory(audio_4_channel_mic)
 family_add_subdirectory(audio_test)
+family_add_subdirectory(audio_test_multi_rate)
 family_add_subdirectory(board_test)
 family_add_subdirectory(cdc_dual_ports)
 family_add_subdirectory(cdc_msc)
 family_add_subdirectory(cdc_msc_freertos)
+family_add_subdirectory(cdc_uac2)
 family_add_subdirectory(dfu)
 family_add_subdirectory(dfu_runtime)
 family_add_subdirectory(dynamic_configuration)
+family_add_subdirectory(hid_boot_interface)
 family_add_subdirectory(hid_composite)
 family_add_subdirectory(hid_composite_freertos)
 family_add_subdirectory(hid_generic_inout)
diff --git a/examples/device/audio_4_channel_mic/CMakeLists.txt b/examples/device/audio_4_channel_mic/CMakeLists.txt
index f6e10e2ea..0f5d36193 100644
--- a/examples/device/audio_4_channel_mic/CMakeLists.txt
+++ b/examples/device/audio_4_channel_mic/CMakeLists.txt
@@ -1,28 +1,38 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
 target_sources(${PROJECT} PUBLIC
   ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
   ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
-)
+  )
 
 # Example include
 target_include_directories(${PROJECT} PUBLIC
   ${CMAKE_CURRENT_SOURCE_DIR}/src
-)
+  )
+
+# Add libm for GCC
+if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
+  target_link_libraries(${PROJECT} PUBLIC m)
+endif()
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/audio_4_channel_mic/Makefile b/examples/device/audio_4_channel_mic/Makefile
index 5a455078e..2c825bbf7 100644
--- a/examples/device/audio_4_channel_mic/Makefile
+++ b/examples/device/audio_4_channel_mic/Makefile
@@ -1,12 +1,14 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
   $(TOP)/hw \
 
 # Example source
-EXAMPLE_SOURCE += $(wildcard src/*.c)
+EXAMPLE_SOURCE += \
+  src/main.c \
+  src/usb_descriptors.c \
+
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/audio_4_channel_mic/skip.txt b/examples/device/audio_4_channel_mic/skip.txt
index ae9b57f1f..157605df1 100644
--- a/examples/device/audio_4_channel_mic/skip.txt
+++ b/examples/device/audio_4_channel_mic/skip.txt
@@ -1,3 +1,5 @@
 mcu:SAMD11
 mcu:SAME5X
-mcu:SAMG
\ No newline at end of file
+mcu:SAMG
+family:broadcom_64bit
+family:espressif
diff --git a/examples/device/audio_4_channel_mic/src/main.c b/examples/device/audio_4_channel_mic/src/main.c
index a6af5fd19..1de4f9dac 100644
--- a/examples/device/audio_4_channel_mic/src/main.c
+++ b/examples/device/audio_4_channel_mic/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Reinhard Panhuber
@@ -34,17 +34,16 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <math.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
+#include "tusb_config.h"
 
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF PROTYPES
 //--------------------------------------------------------------------+
-
-#ifndef AUDIO_SAMPLE_RATE
-#define AUDIO_SAMPLE_RATE   48000
-#endif
+#define AUDIO_SAMPLE_RATE   CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE
 
 /* Blink pattern
  * - 250 ms  : device not mounted
@@ -70,8 +69,13 @@ uint8_t clkValid;
 audio_control_range_2_n_t(1) volumeRng[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX+1]; 			// Volume range state
 audio_control_range_4_n_t(1) sampleFreqRng; 						// Sample frequency range state
 
-// Audio test data
-uint16_t i2s_dummy_buffer[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ/2];   // Ensure half word aligned
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
+// Audio test data, each buffer contains 2 channels, buffer[0] for CH0-1, buffer[1] for CH1-2
+uint16_t i2s_dummy_buffer[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX*CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE/1000/CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO];
+#else
+// Audio test data, 4 channels muxed together, buffer[0] for CH0, buffer[1] for CH1, buffer[2] for CH2, buffer[3] for CH3
+uint16_t i2s_dummy_buffer[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX*CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE/1000];
+#endif
 
 void led_blinking_task(void);
 void audio_task(void);
@@ -84,6 +88,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   // Init values
   sampFreq = AUDIO_SAMPLE_RATE;
   clkValid = 1;
@@ -93,15 +101,51 @@ int main(void)
   sampleFreqRng.subrange[0].bMax = AUDIO_SAMPLE_RATE;
   sampleFreqRng.subrange[0].bRes = 0;
 
+  // Generate dummy data
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
+  uint16_t * p_buff = i2s_dummy_buffer[0];
+  uint16_t dataVal = 1;
+  for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
+  {
+    // CH0 saw wave
+    *p_buff++ = dataVal;
+    // CH1 inverted saw wave
+    *p_buff++ = 60 + AUDIO_SAMPLE_RATE/1000 - dataVal;
+    dataVal++;
+  }
+  p_buff = i2s_dummy_buffer[1];
+  for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
+  {
+    // CH3 square wave
+    *p_buff++ = cnt < (AUDIO_SAMPLE_RATE/1000/2) ? 120:170;
+    // CH4 sinus wave
+    float t = 2*3.1415f * cnt / (AUDIO_SAMPLE_RATE/1000);
+    *p_buff++ = (uint16_t)(sinf(t) * 25) + 200;
+  }
+#else
+  uint16_t * p_buff = i2s_dummy_buffer;
+  uint16_t dataVal = 1;
+  for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
+  {
+    // CH0 saw wave
+    *p_buff++ = dataVal;
+    // CH1 inverted saw wave
+    *p_buff++ = 60 + AUDIO_SAMPLE_RATE/1000 - dataVal;
+    dataVal++;
+    // CH3 square wave
+    *p_buff++ = cnt < (AUDIO_SAMPLE_RATE/1000/2) ? 120:170;
+    // CH4 sinus wave
+    float t = 2*3.1415f * cnt / (AUDIO_SAMPLE_RATE/1000);
+    *p_buff++ = (uint16_t)(sinf(t) * 25) + 200;
+  }
+#endif
+
   while (1)
   {
     tud_task(); // tinyusb device task
     led_blinking_task();
     audio_task();
   }
-
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -132,7 +176,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
@@ -141,8 +185,21 @@ void tud_resume_cb(void)
 
 void audio_task(void)
 {
-  // Yet to be filled - e.g. put meas data into TX FIFOs etc.
-  // asm("nop");
+  // Yet to be filled - e.g. read audio from I2S buffer.
+  // Here we simulate a I2S receive callback every 1ms.
+  static uint32_t start_ms = 0;
+  uint32_t curr_ms = board_millis();
+  if ( start_ms == curr_ms ) return; // not enough time
+  start_ms = curr_ms;
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
+  // Write I2S buffer into FIFO
+  for (uint8_t cnt=0; cnt < 2; cnt++)
+  {
+    tud_audio_write_support_ff(cnt, i2s_dummy_buffer[cnt], AUDIO_SAMPLE_RATE/1000 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX);
+  }
+#else
+  tud_audio_write(i2s_dummy_buffer, AUDIO_SAMPLE_RATE/1000 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX);
+#endif
 }
 
 //--------------------------------------------------------------------+
@@ -290,7 +347,7 @@ bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const *
 
         // Those are dummy values for now
         ret.bNrChannels = 1;
-        ret.bmChannelConfig = 0;
+        ret.bmChannelConfig = (audio_channel_config_t) 0;
         ret.iChannelNames = 0;
 
         TU_LOG2("    Get terminal connector\r\n");
@@ -363,7 +420,8 @@ bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const *
         {
           case AUDIO_CS_REQ_CUR:
             TU_LOG2("    Get Sample Freq.\r\n");
-            return tud_control_xfer(rhport, p_request, &sampFreq, sizeof(sampFreq));
+            // Buffered control transfer is needed for IN flow control to work
+            return tud_audio_buffer_and_schedule_control_xfer(rhport, p_request, &sampFreq, sizeof(sampFreq));
 
           case AUDIO_CS_REQ_RANGE:
             TU_LOG2("    Get Sample Freq. range\r\n");
@@ -399,10 +457,14 @@ bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t itf, uint8_t ep_in, u
   (void) ep_in;
   (void) cur_alt_setting;
 
-  for (uint8_t cnt=0; cnt < CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO; cnt++)
-  {
-    tud_audio_write_support_ff(cnt, i2s_dummy_buffer[cnt], AUDIO_SAMPLE_RATE/1000 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX);
-  }
+
+  // In read world application data flow is driven by I2S clock,
+  // both tud_audio_tx_done_pre_load_cb() & tud_audio_tx_done_post_load_cb() are hardly used.
+  // For example in your I2S receive callback:
+  // void I2S_Rx_Callback(int channel, const void* data, uint16_t samples)
+  // {
+  //    tud_audio_write_support_ff(channel, data, samples * N_BYTES_PER_SAMPLE * N_CHANNEL_PER_FIFO);
+  // }
 
   return true;
 }
@@ -415,22 +477,6 @@ bool tud_audio_tx_done_post_load_cb(uint8_t rhport, uint16_t n_bytes_copied, uin
   (void) ep_in;
   (void) cur_alt_setting;
 
-  uint16_t dataVal;
-
-  // Generate dummy data
-  for (uint16_t cnt = 0; cnt < CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO; cnt++)
-  {
-    uint16_t * p_buff = i2s_dummy_buffer[cnt];              // 2 bytes per sample
-    dataVal = 1;
-    for (uint16_t cnt2 = 0; cnt2 < AUDIO_SAMPLE_RATE/1000; cnt2++)
-    {
-      for (uint8_t cnt3 = 0; cnt3 < CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX; cnt3++)
-      {
-        *p_buff++ = dataVal;
-      }
-      dataVal++;
-    }
-  }
   return true;
 }
 
diff --git a/examples/device/audio_4_channel_mic/src/plot_audio_samples.py b/examples/device/audio_4_channel_mic/src/plot_audio_samples.py
index 9ab15135d..d17a908b6 100644
--- a/examples/device/audio_4_channel_mic/src/plot_audio_samples.py
+++ b/examples/device/audio_4_channel_mic/src/plot_audio_samples.py
@@ -10,11 +10,11 @@ if __name__ == '__main__':
     # print(sd.query_devices())
 
     fs = 48000  		# Sample rate
-    duration = 100e-3   # Duration of recording
+    duration = 1   # Duration of recording
 
     if platform.system() == 'Windows':
         # WDM-KS is needed since there are more than one MicNode device APIs (at least in Windows)
-        device = 'Microphone (MicNode_4_Ch), Windows WDM-KS'
+        device = 'Microphone (MicNode_4_Ch), Windows WASAPI'
     elif platform.system() == 'Darwin':
         device = 'MicNode_4_Ch'
     else:
@@ -25,10 +25,13 @@ if __name__ == '__main__':
     sd.wait()  # Wait until recording is finished
     print('Done!')
 
+
     time = np.arange(0, duration, 1 / fs)  # time vector
+    # strip starting zero
+
     plt.plot(time, myrecording)
     plt.xlabel('Time [s]')
     plt.ylabel('Amplitude')
     plt.title('MicNode 4 Channel')
+    plt.legend(['CH-1', 'CH-2', 'CH-3','CH-4'])
     plt.show()
-    
\ No newline at end of file
diff --git a/examples/device/audio_4_channel_mic/src/tusb_config.h b/examples/device/audio_4_channel_mic/src/tusb_config.h
index 5cf6d07c3..46484f847 100644
--- a/examples/device/audio_4_channel_mic/src/tusb_config.h
+++ b/examples/device/audio_4_channel_mic/src/tusb_config.h
@@ -103,6 +103,7 @@ extern "C" {
 //--------------------------------------------------------------------
 
 // Have a look into audio_device.h for all configurations
+#define CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE              48000
 
 #define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                 TUD_AUDIO_MIC_FOUR_CH_DESC_LEN
 
@@ -112,15 +113,27 @@ extern "C" {
 #define CFG_TUD_AUDIO_ENABLE_EP_IN                    1
 #define CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX    2         // This value is not required by the driver, it parses this information from the descriptor once the alternate interface is set by the host - we use it for the setup
 #define CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX            4         // This value is not required by the driver, it parses this information from the descriptor once the alternate interface is set by the host - we use it for the setup
-#define CFG_TUD_AUDIO_EP_SZ_IN                        (48 + 1) * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX      // 48 Samples (48 kHz) x 2 Bytes/Sample x CFG_TUD_AUDIO_N_CHANNELS_TX Channels - the Windows driver always needs an extra sample per channel of space more, otherwise it complains... found by trial and error
+#define CFG_TUD_AUDIO_EP_SZ_IN                        TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX)
+
+#define CFG_TUD_AUDIO_ENABLE_ENCODING                 1
+#define CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL              1
+
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
+
 #define CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX             CFG_TUD_AUDIO_EP_SZ_IN
 #define CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ          CFG_TUD_AUDIO_EP_SZ_IN
 
-#define CFG_TUD_AUDIO_ENABLE_ENCODING                 1
 #define CFG_TUD_AUDIO_ENABLE_TYPE_I_ENCODING          1
 #define CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX      2         // One I2S stream contains two channels, each stream is saved within one support FIFO - this value is currently fixed, the driver does not support a changing value
 #define CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO        (CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX / CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX)
-#define CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ       (CFG_TUD_AUDIO_EP_SZ_IN / CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO)
+#define CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ       (TUD_OPT_HIGH_SPEED ? 32 : 4) * (CFG_TUD_AUDIO_EP_SZ_IN / CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO) // Example write FIFO every 1ms, so it should be 8 times larger for HS device
+
+#else
+
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX             CFG_TUD_AUDIO_EP_SZ_IN
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ          (TUD_OPT_HIGH_SPEED ? 32 : 4) * CFG_TUD_AUDIO_EP_SZ_IN // Example write FIFO every 1ms, so it should be 8 times larger for HS device
+
+#endif
 
 #ifdef __cplusplus
 }
diff --git a/examples/device/audio_4_channel_mic/src/usb_descriptors.c b/examples/device/audio_4_channel_mic/src/usb_descriptors.c
index 8929f3057..728a5f9ce 100644
--- a/examples/device/audio_4_channel_mic/src/usb_descriptors.c
+++ b/examples/device/audio_4_channel_mic/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -44,7 +45,7 @@ tusb_desc_device_t const desc_device =
     .bDescriptorType    = TUSB_DESC_DEVICE,
     .bcdUSB             = 0x0200,
 
-    // Use Interface Association Descriptor (IAD) for CDC
+    // Use Interface Association Descriptor (IAD) for Audio
     // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
     .bDeviceClass       = TUSB_CLASS_MISC,
     .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
@@ -96,7 +97,7 @@ enum
 
 uint8_t const desc_configuration[] =
 {
-  // Interface count, string index, total length, attribute, power in mA
+  // Config number, interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
 
   // Interface number, string index, EP Out & EP In address, EP size
@@ -116,50 +117,63 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
-{
-    (const char[]) { 0x09, 0x04 }, 	// 0: is supported language is English (0x0409)
-    "PaniRCorp",                   	// 1: Manufacturer
-    "MicNode_4_Ch",    		// 2: Product
-    "123458",                      	// 3: Serials, should use chip ID
-    "UAC2",                 	 	// 4: Audio Interface
+char const* string_desc_arr [] = {
+    (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
+    "PaniRCorp",                   // 1: Manufacturer
+    "MicNode_4_Ch",                // 2: Product
+    NULL,                          // 3: Serials will use unique ID if possible
+    "UAC2",                        // 4: Audio Interface
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Convert ASCII string into UTF-16
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/audio_test/CMakeLists.txt b/examples/device/audio_test/CMakeLists.txt
index cb321f9a8..f61e1b640 100644
--- a/examples/device/audio_test/CMakeLists.txt
+++ b/examples/device/audio_test/CMakeLists.txt
@@ -1,28 +1,33 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
 target_sources(${PROJECT} PUBLIC
   ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
   ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
-)
+  )
 
 # Example include
 target_include_directories(${PROJECT} PUBLIC
   ${CMAKE_CURRENT_SOURCE_DIR}/src
-)
+  )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/audio_test/Makefile b/examples/device/audio_test/Makefile
index 5a455078e..7fa475da5 100644
--- a/examples/device/audio_test/Makefile
+++ b/examples/device/audio_test/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/audio_test/skip.txt b/examples/device/audio_test/skip.txt
index ae9b57f1f..65b137814 100644
--- a/examples/device/audio_test/skip.txt
+++ b/examples/device/audio_test/skip.txt
@@ -1,3 +1,4 @@
 mcu:SAMD11
 mcu:SAME5X
-mcu:SAMG
\ No newline at end of file
+mcu:SAMG
+family:espressif
diff --git a/examples/device/audio_test/src/main.c b/examples/device/audio_test/src/main.c
index d0849c7ac..06783ccfb 100644
--- a/examples/device/audio_test/src/main.c
+++ b/examples/device/audio_test/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Reinhard Panhuber
@@ -35,7 +35,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 //--------------------------------------------------------------------+
@@ -71,7 +71,7 @@ audio_control_range_2_n_t(1) volumeRng[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX+1];
 audio_control_range_4_n_t(1) sampleFreqRng; 						// Sample frequency range state
 
 // Audio test data
-uint16_t test_buffer_audio[CFG_TUD_AUDIO_EP_SZ_IN/2];
+uint16_t test_buffer_audio[(CFG_TUD_AUDIO_EP_SZ_IN - 2) / 2];
 uint16_t startVal = 0;
 
 void led_blinking_task(void);
@@ -85,6 +85,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   // Init values
   sampFreq = AUDIO_SAMPLE_RATE;
   clkValid = 1;
@@ -100,9 +104,6 @@ int main(void)
     led_blinking_task();
     audio_task();
   }
-
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -133,7 +134,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
@@ -291,7 +292,7 @@ bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const *
 
         // Those are dummy values for now
         ret.bNrChannels = 1;
-        ret.bmChannelConfig = 0;
+        ret.bmChannelConfig = (audio_channel_config_t) 0;
         ret.iChannelNames = 0;
 
         TU_LOG2("    Get terminal connector\r\n");
@@ -400,7 +401,7 @@ bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t itf, uint8_t ep_in, u
   (void) ep_in;
   (void) cur_alt_setting;
 
-  tud_audio_write ((uint8_t *)test_buffer_audio, CFG_TUD_AUDIO_EP_SZ_IN);
+  tud_audio_write ((uint8_t *)test_buffer_audio, CFG_TUD_AUDIO_EP_SZ_IN - 2);
 
   return true;
 }
@@ -413,7 +414,7 @@ bool tud_audio_tx_done_post_load_cb(uint8_t rhport, uint16_t n_bytes_copied, uin
   (void) ep_in;
   (void) cur_alt_setting;
 
-  for (size_t cnt = 0; cnt < CFG_TUD_AUDIO_EP_SZ_IN/2; cnt++)
+  for (size_t cnt = 0; cnt < (CFG_TUD_AUDIO_EP_SZ_IN - 2) / 2; cnt++)
   {
     test_buffer_audio[cnt] = startVal++;
   }
diff --git a/examples/device/audio_test/src/plot_audio_samples.py b/examples/device/audio_test/src/plot_audio_samples.py
index 6e3c4978e..1504684a6 100644
--- a/examples/device/audio_test/src/plot_audio_samples.py
+++ b/examples/device/audio_test/src/plot_audio_samples.py
@@ -2,6 +2,7 @@ import sounddevice as sd
 import matplotlib.pyplot as plt
 import numpy as np
 import platform
+import csv
 
 if __name__ == '__main__':
 
@@ -31,4 +32,6 @@ if __name__ == '__main__':
     plt.ylabel('Amplitude')
     plt.title('MicNode')
     plt.show()
-    
\ No newline at end of file
+
+    samples = np.array(myrecording)
+    np.savetxt('Output.csv', samples, delimiter=",", fmt='%s')
diff --git a/examples/device/audio_test/src/tusb_config.h b/examples/device/audio_test/src/tusb_config.h
index 355ed1011..9f38612a9 100644
--- a/examples/device/audio_test/src/tusb_config.h
+++ b/examples/device/audio_test/src/tusb_config.h
@@ -114,7 +114,7 @@ extern "C" {
 #define CFG_TUD_AUDIO_ENABLE_EP_IN                                    1
 #define CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX                    2                                       // Driver gets this info from the descriptors - we define it here to use it to setup the descriptors and to do calculations with it below
 #define CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX                            1                                       // Driver gets this info from the descriptors - we define it here to use it to setup the descriptors and to do calculations with it below - be aware: for different number of channels you need another descriptor!
-#define CFG_TUD_AUDIO_EP_SZ_IN                                        48 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX      // 48 Samples (48 kHz) x 2 Bytes/Sample x 1 Channel
+#define CFG_TUD_AUDIO_EP_SZ_IN                                        (48 + 1) * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX      // 48 Samples (48 kHz) x 2 Bytes/Sample x CFG_TUD_AUDIO_N_CHANNELS_TX Channels - One extra sample is needed for asynchronous transfer adjustment, see feedback EP
 #define CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX                             CFG_TUD_AUDIO_EP_SZ_IN                  // Maximum EP IN size for all AS alternate settings used
 #define CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ                          CFG_TUD_AUDIO_EP_SZ_IN + 1
 
diff --git a/examples/device/audio_test/src/usb_descriptors.c b/examples/device/audio_test/src/usb_descriptors.c
index da3e203d7..9864377f6 100644
--- a/examples/device/audio_test/src/usb_descriptors.c
+++ b/examples/device/audio_test/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -44,7 +45,7 @@ tusb_desc_device_t const desc_device =
     .bDescriptorType    = TUSB_DESC_DEVICE,
     .bcdUSB             = 0x0200,
 
-    // Use Interface Association Descriptor (IAD) for CDC
+    // Use Interface Association Descriptor (IAD) for Audio
     // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
     .bDeviceClass       = TUSB_CLASS_MISC,
     .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
@@ -96,7 +97,7 @@ enum
 
 uint8_t const desc_configuration[] =
 {
-    // Interface count, string index, total length, attribute, power in mA
+    // Config number, interface count, string index, total length, attribute, power in mA
     TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
 
     // Interface number, string index, EP Out & EP In address, EP size
@@ -116,50 +117,65 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
 char const* string_desc_arr [] =
 {
-    (const char[]) { 0x09, 0x04 }, 	// 0: is supported language is English (0x0409)
-    "PaniRCorp",                   	// 1: Manufacturer
-    "MicNode",              		// 2: Product
-    "123456",                      	// 3: Serials, should use chip ID
-    "UAC2",                 	 	// 4: Audio Interface
+    (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
+    "PaniRCorp",                   // 1: Manufacturer
+    "MicNode",                     // 2: Product
+    NULL,                          // 3: Serials will use unique ID if possible
+    "UAC2",                        // 4: Audio Interface
+
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Convert ASCII string into UTF-16
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/audio_test_multi_rate/CMakeLists.txt b/examples/device/audio_test_multi_rate/CMakeLists.txt
new file mode 100644
index 000000000..f61e1b640
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/CMakeLists.txt
@@ -0,0 +1,33 @@
+cmake_minimum_required(VERSION 3.17)
+
+include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
+
+# gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
+family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
+
+project(${PROJECT} C CXX ASM)
+
+# Checks this example is valid for the family and initializes the project
+family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
+add_executable(${PROJECT})
+
+# Example source
+target_sources(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
+
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
+
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/audio_test_multi_rate/Makefile b/examples/device/audio_test_multi_rate/Makefile
new file mode 100644
index 000000000..7fa475da5
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/Makefile
@@ -0,0 +1,11 @@
+include ../../build_system/make/make.mk
+
+INC += \
+  src \
+  $(TOP)/hw \
+
+# Example source
+EXAMPLE_SOURCE += $(wildcard src/*.c)
+SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
+
+include ../../build_system/make/rules.mk
diff --git a/examples/device/audio_test_multi_rate/skip.txt b/examples/device/audio_test_multi_rate/skip.txt
new file mode 100644
index 000000000..65b137814
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/skip.txt
@@ -0,0 +1,4 @@
+mcu:SAMD11
+mcu:SAME5X
+mcu:SAMG
+family:espressif
diff --git a/examples/device/audio_test_multi_rate/src/main.c b/examples/device/audio_test_multi_rate/src/main.c
new file mode 100644
index 000000000..3e7f40dac
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/src/main.c
@@ -0,0 +1,525 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Reinhard Panhuber
+ * Copyright (c) 2022 HiFiPhile
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+/* plot_audio_samples.py requires following modules:
+ * $ sudo apt install libportaudio
+ * $ pip3 install sounddevice matplotlib
+ *
+ * Then run
+ * $ python3 plot_audio_samples.py
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "bsp/board_api.h"
+#include "tusb.h"
+#include "usb_descriptors.h"
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF PROTYPES
+//--------------------------------------------------------------------+
+
+/* Blink pattern
+ * - 250 ms  : device not mounted
+ * - 1000 ms : device mounted
+ * - 2500 ms : device is suspended
+ */
+enum  {
+  BLINK_NOT_MOUNTED = 250,
+  BLINK_MOUNTED = 1000,
+  BLINK_SUSPENDED = 2500,
+};
+
+static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
+
+// Audio controls
+// Current states
+bool mute[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX + 1]; 				          // +1 for master channel 0
+uint16_t volume[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX + 1]; 					// +1 for master channel 0
+uint32_t sampFreq;
+uint8_t bytesPerSample;
+uint8_t clkValid;
+
+// Range states
+// List of supported sample rates
+static const uint32_t sampleRatesList[] =
+{
+    32000, 48000, 96000
+};
+
+#define N_sampleRates  TU_ARRAY_SIZE(sampleRatesList)
+
+// Bytes per format of every Alt settings
+static const uint8_t bytesPerSampleAltList[CFG_TUD_AUDIO_FUNC_1_N_FORMATS] =
+{
+    CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX,
+    CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX,
+};
+
+audio_control_range_2_n_t(1) volumeRng[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX+1]; 			// Volume range state
+
+
+// Audio test data
+CFG_TUSB_MEM_ALIGN uint8_t test_buffer_audio[CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX];
+uint16_t startVal = 0;
+
+void led_blinking_task(void);
+void audio_task(void);
+
+/*------------- MAIN -------------*/
+int main(void)
+{
+  board_init();
+
+  // init device stack on configured roothub port
+  tud_init(BOARD_TUD_RHPORT);
+
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
+  // Init values
+  sampFreq = sampleRatesList[0];
+  clkValid = 1;
+
+  while (1)
+  {
+    tud_task(); // tinyusb device task
+    led_blinking_task();
+    audio_task();
+  }
+
+
+  return 0;
+}
+
+//--------------------------------------------------------------------+
+// Device callbacks
+//--------------------------------------------------------------------+
+
+// Invoked when device is mounted
+void tud_mount_cb(void)
+{
+  blink_interval_ms = BLINK_MOUNTED;
+}
+
+// Invoked when device is unmounted
+void tud_umount_cb(void)
+{
+  blink_interval_ms = BLINK_NOT_MOUNTED;
+}
+
+// Invoked when usb bus is suspended
+// remote_wakeup_en : if host allow us  to perform remote wakeup
+// Within 7ms, device must draw an average of current less than 2.5 mA from bus
+void tud_suspend_cb(bool remote_wakeup_en)
+{
+  (void) remote_wakeup_en;
+  blink_interval_ms = BLINK_SUSPENDED;
+}
+
+// Invoked when usb bus is resumed
+void tud_resume_cb(void)
+{
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
+}
+
+//--------------------------------------------------------------------+
+// AUDIO Task
+//--------------------------------------------------------------------+
+
+void audio_task(void)
+{
+  // Yet to be filled - e.g. put meas data into TX FIFOs etc.
+  // asm("nop");
+}
+
+//--------------------------------------------------------------------+
+// Application Callback API Implementations
+//--------------------------------------------------------------------+
+
+// Invoked when set interface is called, typically on start/stop streaming or format change
+bool tud_audio_set_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request)
+{
+  (void)rhport;
+  //uint8_t const itf = tu_u16_low(tu_le16toh(p_request->wIndex));
+  uint8_t const alt = tu_u16_low(tu_le16toh(p_request->wValue));
+
+  // Clear buffer when streaming format is changed
+  if(alt != 0)
+  {
+    bytesPerSample = bytesPerSampleAltList[alt-1];
+  }
+  return true;
+}
+
+// Invoked when audio class specific set request received for an EP
+bool tud_audio_set_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff)
+{
+  (void) rhport;
+  (void) pBuff;
+
+  // We do not support any set range requests here, only current value requests
+  TU_VERIFY(p_request->bRequest == AUDIO_CS_REQ_CUR);
+
+  // Page 91 in UAC2 specification
+  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
+  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+  uint8_t ep = TU_U16_LOW(p_request->wIndex);
+
+  (void) channelNum; (void) ctrlSel; (void) ep;
+
+  return false; 	// Yet not implemented
+}
+
+// Invoked when audio class specific set request received for an interface
+bool tud_audio_set_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff)
+{
+  (void) rhport;
+  (void) pBuff;
+
+  // We do not support any set range requests here, only current value requests
+  TU_VERIFY(p_request->bRequest == AUDIO_CS_REQ_CUR);
+
+  // Page 91 in UAC2 specification
+  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
+  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+  uint8_t itf = TU_U16_LOW(p_request->wIndex);
+
+  (void) channelNum; (void) ctrlSel; (void) itf;
+
+  return false; 	// Yet not implemented
+}
+
+// Invoked when audio class specific set request received for an entity
+bool tud_audio_set_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff)
+{
+  (void) rhport;
+
+  // Page 91 in UAC2 specification
+  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
+  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+  uint8_t itf = TU_U16_LOW(p_request->wIndex);
+  uint8_t entityID = TU_U16_HIGH(p_request->wIndex);
+
+  (void) itf;
+
+  // We do not support any set range requests here, only current value requests
+  TU_VERIFY(p_request->bRequest == AUDIO_CS_REQ_CUR);
+
+  // If request is for our feature unit
+  if ( entityID == UAC2_ENTITY_FEATURE_UNIT )
+  {
+    switch ( ctrlSel )
+    {
+      case AUDIO_FU_CTRL_MUTE:
+        // Request uses format layout 1
+        TU_VERIFY(p_request->wLength == sizeof(audio_control_cur_1_t));
+
+        mute[channelNum] = ((audio_control_cur_1_t*) pBuff)->bCur;
+
+        TU_LOG2("    Set Mute: %d of channel: %u\r\n", mute[channelNum], channelNum);
+      return true;
+
+      case AUDIO_FU_CTRL_VOLUME:
+        // Request uses format layout 2
+        TU_VERIFY(p_request->wLength == sizeof(audio_control_cur_2_t));
+
+        volume[channelNum] = (uint16_t) ((audio_control_cur_2_t*) pBuff)->bCur;
+
+        TU_LOG2("    Set Volume: %d dB of channel: %u\r\n", volume[channelNum], channelNum);
+      return true;
+
+        // Unknown/Unsupported control
+      default:
+        TU_BREAKPOINT();
+      return false;
+    }
+  }
+
+  // Clock Source unit
+  if ( entityID == UAC2_ENTITY_CLOCK )
+  {
+    switch ( ctrlSel )
+    {
+      case AUDIO_CS_CTRL_SAM_FREQ:
+        TU_VERIFY(p_request->wLength == sizeof(audio_control_cur_4_t));
+
+        sampFreq = (uint32_t)((audio_control_cur_4_t *)pBuff)->bCur;
+
+        TU_LOG2("Clock set current freq: %lu\r\n", sampFreq);
+
+        return true;
+      break;
+
+      // Unknown/Unsupported control
+      default:
+        TU_BREAKPOINT();
+        return false;
+    }
+  }
+
+  return false;    // Yet not implemented
+}
+
+// Invoked when audio class specific get request received for an EP
+bool tud_audio_get_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request)
+{
+  (void) rhport;
+
+  // Page 91 in UAC2 specification
+  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
+  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+  uint8_t ep = TU_U16_LOW(p_request->wIndex);
+
+  (void) channelNum; (void) ctrlSel; (void) ep;
+
+  //	return tud_control_xfer(rhport, p_request, &tmp, 1);
+
+  return false; 	// Yet not implemented
+}
+
+// Invoked when audio class specific get request received for an interface
+bool tud_audio_get_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request)
+{
+  (void) rhport;
+
+  // Page 91 in UAC2 specification
+  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
+  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+  uint8_t itf = TU_U16_LOW(p_request->wIndex);
+
+  (void) channelNum; (void) ctrlSel; (void) itf;
+
+  return false; 	// Yet not implemented
+}
+
+// Invoked when audio class specific get request received for an entity
+bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request)
+{
+  (void) rhport;
+
+  // Page 91 in UAC2 specification
+  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
+  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+  // uint8_t itf = TU_U16_LOW(p_request->wIndex); 			// Since we have only one audio function implemented, we do not need the itf value
+  uint8_t entityID = TU_U16_HIGH(p_request->wIndex);
+
+  // Input terminal (Microphone input)
+  if (entityID == UAC2_ENTITY_INPUT_TERMINAL)
+  {
+    switch ( ctrlSel )
+    {
+      case AUDIO_TE_CTRL_CONNECTOR:
+      {
+        // The terminal connector control only has a get request with only the CUR attribute.
+        audio_desc_channel_cluster_t ret;
+
+        // Those are dummy values for now
+        ret.bNrChannels = 1;
+        ret.bmChannelConfig = 0;
+        ret.iChannelNames = 0;
+
+        TU_LOG2("    Get terminal connector\r\n");
+
+        return tud_audio_buffer_and_schedule_control_xfer(rhport, p_request, (void*) &ret, sizeof(ret));
+      }
+      break;
+
+        // Unknown/Unsupported control selector
+      default:
+        TU_BREAKPOINT();
+        return false;
+    }
+  }
+
+  // Feature unit
+  if (entityID == UAC2_ENTITY_FEATURE_UNIT)
+  {
+    switch ( ctrlSel )
+    {
+      case AUDIO_FU_CTRL_MUTE:
+        // Audio control mute cur parameter block consists of only one byte - we thus can send it right away
+        // There does not exist a range parameter block for mute
+        TU_LOG2("    Get Mute of channel: %u\r\n", channelNum);
+        return tud_control_xfer(rhport, p_request, &mute[channelNum], 1);
+
+      case AUDIO_FU_CTRL_VOLUME:
+        switch ( p_request->bRequest )
+        {
+          case AUDIO_CS_REQ_CUR:
+            TU_LOG2("    Get Volume of channel: %u\r\n", channelNum);
+            return tud_control_xfer(rhport, p_request, &volume[channelNum], sizeof(volume[channelNum]));
+
+          case AUDIO_CS_REQ_RANGE:
+            TU_LOG2("    Get Volume range of channel: %u\r\n", channelNum);
+
+            // Copy values - only for testing - better is version below
+            audio_control_range_2_n_t(1)
+            ret;
+
+            ret.wNumSubRanges = 1;
+            ret.subrange[0].bMin = -90;    // -90 dB
+            ret.subrange[0].bMax = 30;		// +30 dB
+            ret.subrange[0].bRes = 1; 		// 1 dB steps
+
+            return tud_audio_buffer_and_schedule_control_xfer(rhport, p_request, (void*) &ret, sizeof(ret));
+
+            // Unknown/Unsupported control
+          default:
+            TU_BREAKPOINT();
+            return false;
+        }
+      break;
+
+        // Unknown/Unsupported control
+      default:
+        TU_BREAKPOINT();
+        return false;
+    }
+  }
+
+  // Clock Source unit
+  if ( entityID == UAC2_ENTITY_CLOCK )
+  {
+    switch ( ctrlSel )
+    {
+      case AUDIO_CS_CTRL_SAM_FREQ:
+        // channelNum is always zero in this case
+        switch ( p_request->bRequest )
+        {
+          case AUDIO_CS_REQ_CUR:
+            TU_LOG2("    Get Sample Freq.\r\n");
+            return tud_control_xfer(rhport, p_request, &sampFreq, sizeof(sampFreq));
+
+          case AUDIO_CS_REQ_RANGE:
+          {
+            TU_LOG2("    Get Sample Freq. range\r\n");
+            audio_control_range_4_n_t(N_sampleRates) rangef =
+            {
+                .wNumSubRanges = tu_htole16(N_sampleRates)
+            };
+            TU_LOG1("Clock get %d freq ranges\r\n", N_sampleRates);
+            for(uint8_t i = 0; i < N_sampleRates; i++)
+            {
+                rangef.subrange[i].bMin = (int32_t)sampleRatesList[i];
+                rangef.subrange[i].bMax = (int32_t)sampleRatesList[i];
+                rangef.subrange[i].bRes = 0;
+                TU_LOG1("Range %d (%d, %d, %d)\r\n", i, (int)rangef.subrange[i].bMin, (int)rangef.subrange[i].bMax, (int)rangef.subrange[i].bRes);
+            }
+            return tud_audio_buffer_and_schedule_control_xfer(rhport, p_request, &rangef, sizeof(rangef));
+          }
+           // Unknown/Unsupported control
+          default:
+            TU_BREAKPOINT();
+            return false;
+        }
+      break;
+
+      case AUDIO_CS_CTRL_CLK_VALID:
+        // Only cur attribute exists for this request
+        TU_LOG2("    Get Sample Freq. valid\r\n");
+        return tud_control_xfer(rhport, p_request, &clkValid, sizeof(clkValid));
+
+      // Unknown/Unsupported control
+      default:
+        TU_BREAKPOINT();
+        return false;
+    }
+  }
+
+  TU_LOG2("  Unsupported entity: %d\r\n", entityID);
+  return false; 	// Yet not implemented
+}
+
+bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t itf, uint8_t ep_in, uint8_t cur_alt_setting)
+{
+  (void) rhport;
+  (void) itf;
+  (void) ep_in;
+  (void) cur_alt_setting;
+
+  tud_audio_write((uint8_t *)test_buffer_audio, (uint16_t)(sampFreq / (TUD_OPT_HIGH_SPEED ? 8000 : 1000) * bytesPerSample));
+
+  return true;
+}
+
+bool tud_audio_tx_done_post_load_cb(uint8_t rhport, uint16_t n_bytes_copied, uint8_t itf, uint8_t ep_in, uint8_t cur_alt_setting)
+{
+  (void) rhport;
+  (void) n_bytes_copied;
+  (void) itf;
+  (void) ep_in;
+  (void) cur_alt_setting;
+
+  // 16bit
+  if(bytesPerSample == 2)
+  {
+    uint16_t* pData_16 = (uint16_t*)((void*)test_buffer_audio);
+    for (size_t cnt = 0; cnt < sampFreq / (TUD_OPT_HIGH_SPEED ? 8000 : 1000); cnt++)
+    {
+      pData_16[cnt] = startVal++;
+    }
+  }
+  // 24bit in 32bit slot
+  else if(bytesPerSample == 4)
+  {
+    uint32_t* pData_32 = (uint32_t*)((void*)test_buffer_audio);
+    for (size_t cnt = 0; cnt < sampFreq / (TUD_OPT_HIGH_SPEED ? 8000 : 1000); cnt++)
+    {
+      pData_32[cnt] = (uint32_t)startVal++ << 16U;
+    }
+  }
+
+  return true;
+}
+
+bool tud_audio_set_itf_close_EP_cb(uint8_t rhport, tusb_control_request_t const * p_request)
+{
+  (void) rhport;
+  (void) p_request;
+  startVal = 0;
+
+  return true;
+}
+
+//--------------------------------------------------------------------+
+// BLINKING TASK
+//--------------------------------------------------------------------+
+void led_blinking_task(void)
+{
+  static uint32_t start_ms = 0;
+  static bool led_state = false;
+
+  // Blink every interval ms
+  if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
+  start_ms += blink_interval_ms;
+
+  board_led_write(led_state);
+  led_state = 1 - led_state; // toggle
+}
diff --git a/examples/device/audio_test_multi_rate/src/plot_audio_samples.py b/examples/device/audio_test_multi_rate/src/plot_audio_samples.py
new file mode 100644
index 000000000..c92e49957
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/src/plot_audio_samples.py
@@ -0,0 +1,37 @@
+import sounddevice as sd
+import matplotlib.pyplot as plt
+import numpy as np
+import platform
+import csv
+
+if __name__ == '__main__':
+
+    # If you got "ValueError: No input device matching", that is because your PC name example device
+    # differently from tested list below. Uncomment the next line to see full list and try to pick correct one
+    # print(sd.query_devices())
+
+    fs = 96000           # Sample rate
+    duration = 100e-3    # Duration of recording
+
+    if platform.system() == 'Windows':
+        # MME is needed since there are more than one MicNode device APIs (at least in Windows)
+        device = 'Microphone (MicNode) MME'
+    elif platform.system() == 'Darwin':
+        device = 'MicNode'
+    else:
+        device ='default'
+
+    myrecording = sd.rec(int(duration * fs), samplerate=fs, channels=1, dtype='int16', device=device)
+    print('Waiting...')
+    sd.wait()  # Wait until recording is finished
+    print('Done!')
+
+    time = np.arange(0, duration, 1 / fs)  # time vector
+    plt.plot(time, myrecording)
+    plt.xlabel('Time [s]')
+    plt.ylabel('Amplitude')
+    plt.title('MicNode')
+    plt.show()
+
+    samples = np.array(myrecording)
+    np.savetxt('Output.csv', samples, delimiter=",", fmt='%s')
diff --git a/examples/device/audio_test_multi_rate/src/tusb_config.h b/examples/device/audio_test_multi_rate/src/tusb_config.h
new file mode 100644
index 000000000..1c8288bce
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/src/tusb_config.h
@@ -0,0 +1,141 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _TUSB_CONFIG_H_
+#define _TUSB_CONFIG_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "usb_descriptors.h"
+
+//--------------------------------------------------------------------+
+// Board Specific Configuration
+//--------------------------------------------------------------------+
+
+// RHPort number used for device can be defined by board.mk, default to port 0
+#ifndef BOARD_TUD_RHPORT
+#define BOARD_TUD_RHPORT      0
+#endif
+
+// RHPort max operational speed can defined by board.mk
+#ifndef BOARD_TUD_MAX_SPEED
+#define BOARD_TUD_MAX_SPEED   OPT_MODE_DEFAULT_SPEED
+#endif
+
+//--------------------------------------------------------------------
+// COMMON CONFIGURATION
+//--------------------------------------------------------------------
+
+// defined by compiler flags for flexibility
+#ifndef CFG_TUSB_MCU
+#error CFG_TUSB_MCU must be defined
+#endif
+
+#ifndef CFG_TUSB_OS
+#define CFG_TUSB_OS                 OPT_OS_NONE
+#endif
+
+#ifndef CFG_TUSB_DEBUG
+#define CFG_TUSB_DEBUG              0
+#endif
+
+// Enable Device stack
+#define CFG_TUD_ENABLED       1
+
+// Default is max speed that hardware controller could support with on-chip PHY
+#define CFG_TUD_MAX_SPEED     BOARD_TUD_MAX_SPEED
+
+// CFG_TUSB_DEBUG is defined by compiler in DEBUG build
+// #define CFG_TUSB_DEBUG           0
+
+/* USB DMA on some MCUs can only access a specific SRAM region with restriction on alignment.
+ * Tinyusb use follows macros to declare transferring memory so that they can be put
+ * into those specific section.
+ * e.g
+ * - CFG_TUSB_MEM SECTION : __attribute__ (( section(".usb_ram") ))
+ * - CFG_TUSB_MEM_ALIGN   : __attribute__ ((aligned(4)))
+ */
+#ifndef CFG_TUSB_MEM_SECTION
+#define CFG_TUSB_MEM_SECTION
+#endif
+
+#ifndef CFG_TUSB_MEM_ALIGN
+#define CFG_TUSB_MEM_ALIGN          __attribute__ ((aligned(4)))
+#endif
+
+//--------------------------------------------------------------------
+// DEVICE CONFIGURATION
+//--------------------------------------------------------------------
+
+#ifndef CFG_TUD_ENDPOINT0_SIZE
+#define CFG_TUD_ENDPOINT0_SIZE    64
+#endif
+
+//------------- CLASS -------------//
+#define CFG_TUD_AUDIO             1
+#define CFG_TUD_CDC               0
+#define CFG_TUD_MSC               0
+#define CFG_TUD_HID               0
+#define CFG_TUD_MIDI              0
+#define CFG_TUD_VENDOR            0
+
+//--------------------------------------------------------------------
+// AUDIO CLASS DRIVER CONFIGURATION
+//--------------------------------------------------------------------
+
+#define CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE                         96000
+
+// How many formats are used, need to adjust USB descriptor if changed
+#define CFG_TUD_AUDIO_FUNC_1_N_FORMATS                               2
+
+// 16bit in 16bit slots
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX          2
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX                  16
+
+// 24bit in 32bit slots
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX          4
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_RX                  24
+
+// Have a look into audio_device.h for all configurations
+
+#define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                                 TUD_AUDIO_MIC_ONE_CH_2_FORMAT_DESC_LEN
+#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT                                 1                                       // Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
+#define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ                              64                                      // Size of control request buffer
+
+#define CFG_TUD_AUDIO_ENABLE_EP_IN                                    1
+#define CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX                            1                                       // Driver gets this info from the descriptors - we define it here to use it to setup the descriptors and to do calculations with it below - be aware: for different number of channels you need another descriptor!
+
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN                        TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX)
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_IN                        TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX)
+
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX                             TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_IN)                  // Maximum EP IN size for all AS alternate settings used
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ                          CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _TUSB_CONFIG_H_ */
diff --git a/examples/device/audio_test_multi_rate/src/usb_descriptors.c b/examples/device/audio_test_multi_rate/src/usb_descriptors.c
new file mode 100644
index 000000000..f50e70a25
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/src/usb_descriptors.c
@@ -0,0 +1,185 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ * Copyright (c) 2022 HiFiPhile
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "bsp/board_api.h"
+#include "tusb.h"
+#include "usb_descriptors.h"
+
+/* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
+ * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
+ *
+ * Auto ProductID layout's Bitmap:
+ *   [MSB]     AUDIO | MIDI | HID | MSC | CDC          [LSB]
+ */
+#define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
+#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
+    _PID_MAP(MIDI, 3) | _PID_MAP(AUDIO, 4) | _PID_MAP(VENDOR, 5) )
+
+//--------------------------------------------------------------------+
+// Device Descriptors
+//--------------------------------------------------------------------+
+tusb_desc_device_t const desc_device =
+{
+    .bLength            = sizeof(tusb_desc_device_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bcdUSB             = 0x0200,
+
+    // Use Interface Association Descriptor (IAD) for Audio
+    // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+
+    .idVendor           = 0xCafe,
+    .idProduct          = USB_PID,
+    .bcdDevice          = 0x0100,
+
+    .iManufacturer      = 0x01,
+    .iProduct           = 0x02,
+    .iSerialNumber      = 0x03,
+
+    .bNumConfigurations = 0x01
+};
+
+// Invoked when received GET DEVICE DESCRIPTOR
+// Application return pointer to descriptor
+uint8_t const * tud_descriptor_device_cb(void)
+{
+  return (uint8_t const *) &desc_device;
+}
+
+//--------------------------------------------------------------------+
+// Configuration Descriptor
+//--------------------------------------------------------------------+
+enum
+{
+  ITF_NUM_AUDIO_CONTROL = 0,
+  ITF_NUM_AUDIO_STREAMING,
+  ITF_NUM_TOTAL
+};
+
+#define CONFIG_TOTAL_LEN    	(TUD_CONFIG_DESC_LEN + CFG_TUD_AUDIO * TUD_AUDIO_MIC_ONE_CH_2_FORMAT_DESC_LEN)
+
+#if CFG_TUSB_MCU == OPT_MCU_LPC175X_6X || CFG_TUSB_MCU == OPT_MCU_LPC177X_8X || CFG_TUSB_MCU == OPT_MCU_LPC40XX
+  // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
+  // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In etc ...
+  #define EPNUM_AUDIO   0x03
+
+#elif TU_CHECK_MCU(OPT_MCU_NRF5X)
+  // nRF5x ISO can only be endpoint 8
+  #define EPNUM_AUDIO   0x08
+
+#else
+  #define EPNUM_AUDIO   0x01
+#endif
+
+uint8_t const desc_configuration[] =
+{
+    // Config number, interface count, string index, total length, attribute, power in mA
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
+
+    // Interface number, string index, EP Out & EP In address, EP size
+    TUD_AUDIO_MIC_ONE_CH_2_FORMAT_DESCRIPTOR(/*_itfnum*/ ITF_NUM_AUDIO_CONTROL, /*_stridx*/ 0, /*_epin*/ 0x80 | EPNUM_AUDIO)
+};
+
+TU_VERIFY_STATIC(sizeof(desc_configuration) == CONFIG_TOTAL_LEN, "Incorrect size");
+
+// Invoked when received GET CONFIGURATION DESCRIPTOR
+// Application return pointer to descriptor
+// Descriptor contents must exist long enough for transfer to complete
+uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
+{
+  (void) index; // for multiple configurations
+  return desc_configuration;
+}
+
+//--------------------------------------------------------------------+
+// String Descriptors
+//--------------------------------------------------------------------+
+
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
+// array of pointer to string descriptors
+char const* string_desc_arr [] =
+{
+    (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
+    "PaniRCorp",                   // 1: Manufacturer
+    "MicNode",                     // 2: Product
+    NULL,                          // 3: Serials will use unique ID if possible
+    "UAC2",                        // 4: Audio Interface
+
+};
+
+static uint16_t _desc_str[32 + 1];
+
+// Invoked when received GET STRING DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
+  (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
+
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
+
+      const char *str = string_desc_arr[index];
+
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
+
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
+  }
+
+  // first byte is length (including header), second byte is string type
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
+
+  return _desc_str;
+}
diff --git a/examples/device/audio_test_multi_rate/src/usb_descriptors.h b/examples/device/audio_test_multi_rate/src/usb_descriptors.h
new file mode 100644
index 000000000..8381e31f5
--- /dev/null
+++ b/examples/device/audio_test_multi_rate/src/usb_descriptors.h
@@ -0,0 +1,102 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 HiFiPhile
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _USB_DESCRIPTORS_H_
+#define _USB_DESCRIPTORS_H_
+
+// #include "tusb.h"
+
+// Unit numbers are arbitrary selected
+#define UAC2_ENTITY_CLOCK                   0x04
+#define UAC2_ENTITY_INPUT_TERMINAL          0x01
+#define UAC2_ENTITY_OUTPUT_TERMINAL         0x03
+#define UAC2_ENTITY_FEATURE_UNIT            0x02
+
+
+#define TUD_AUDIO_MIC_ONE_CH_2_FORMAT_DESC_LEN (TUD_AUDIO_DESC_IAD_LEN\
+    + TUD_AUDIO_DESC_STD_AC_LEN\
+    + TUD_AUDIO_DESC_CS_AC_LEN\
+    + TUD_AUDIO_DESC_CLK_SRC_LEN\
+    + TUD_AUDIO_DESC_INPUT_TERM_LEN\
+    + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
+    + TUD_AUDIO_DESC_FEATURE_UNIT_ONE_CHANNEL_LEN\
+    /* Interface 1, Alternate 0 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    /* Interface 1, Alternate 1 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
+    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
+    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
+    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
+    /* Interface 1, Alternate 2 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
+    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
+    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
+    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN)
+
+
+#define TUD_AUDIO_MIC_ONE_CH_2_FORMAT_DESCRIPTOR(_itfnum, _stridx, _epin) \
+  /* Standard Interface Association Descriptor (IAD) */\
+  TUD_AUDIO_DESC_IAD(/*_firstitf*/ _itfnum, /*_nitfs*/ 0x02, /*_stridx*/ 0x00),\
+  /* Standard AC Interface Descriptor(4.7.1) */\
+  TUD_AUDIO_DESC_STD_AC(/*_itfnum*/ _itfnum, /*_nEPs*/ 0x00, /*_stridx*/ _stridx),\
+  /* Class-Specific AC Interface Header Descriptor(4.7.2) */\
+  TUD_AUDIO_DESC_CS_AC(/*_bcdADC*/ 0x0200, /*_category*/ AUDIO_FUNC_MICROPHONE, /*_totallen*/ TUD_AUDIO_DESC_CLK_SRC_LEN+TUD_AUDIO_DESC_INPUT_TERM_LEN+TUD_AUDIO_DESC_OUTPUT_TERM_LEN+TUD_AUDIO_DESC_FEATURE_UNIT_ONE_CHANNEL_LEN, /*_ctrl*/ AUDIO_CS_AS_INTERFACE_CTRL_LATENCY_POS),\
+  /* Clock Source Descriptor(4.7.2.1) */\
+  TUD_AUDIO_DESC_CLK_SRC(/*_clkid*/ UAC2_ENTITY_CLOCK, /*_attr*/ AUDIO_CLOCK_SOURCE_ATT_INT_PRO_CLK, /*_ctrl*/ AUDIO_CTRL_RW << AUDIO_CLOCK_SOURCE_CTRL_CLK_FRQ_POS | AUDIO_CTRL_R << AUDIO_CLOCK_SOURCE_CTRL_CLK_VAL_POS, /*_assocTerm*/ 0x01,  /*_stridx*/ 0x00),\
+  /* Input Terminal Descriptor(4.7.2.4) */\
+  TUD_AUDIO_DESC_INPUT_TERM(/*_termid*/ UAC2_ENTITY_INPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_IN_GENERIC_MIC, /*_assocTerm*/ UAC2_ENTITY_OUTPUT_TERMINAL, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_nchannelslogical*/ 0x01, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_idxchannelnames*/ 0x00, /*_ctrl*/ AUDIO_CTRL_R << AUDIO_IN_TERM_CTRL_CONNECTOR_POS, /*_stridx*/ 0x00),\
+  /* Output Terminal Descriptor(4.7.2.5) */\
+  TUD_AUDIO_DESC_OUTPUT_TERM(/*_termid*/ UAC2_ENTITY_OUTPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_USB_STREAMING, /*_assocTerm*/ UAC2_ENTITY_INPUT_TERMINAL, /*_srcid*/ UAC2_ENTITY_FEATURE_UNIT, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_ctrl*/ 0x0000, /*_stridx*/ 0x00),\
+  /* Feature Unit Descriptor(4.7.2.8) */\
+  TUD_AUDIO_DESC_FEATURE_UNIT_ONE_CHANNEL(/*_unitid*/ UAC2_ENTITY_FEATURE_UNIT, /*_srcid*/ 0x01, /*_ctrlch0master*/ AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS, /*_ctrlch1*/ AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS, /*_stridx*/ 0x00),\
+  /* Standard AS Interface Descriptor(4.9.1) */\
+  /* Interface 1, Alternate 0 - default alternate setting with 0 bandwidth */\
+  TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)((_itfnum)+1), /*_altset*/ 0x00, /*_nEPs*/ 0x00, /*_stridx*/ 0x00),\
+  /* Standard AS Interface Descriptor(4.9.1) */\
+  /* Interface 1, Alternate 1 - alternate interface for data streaming */\
+  TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)((_itfnum)+1), /*_altset*/ 0x01, /*_nEPs*/ 0x01, /*_stridx*/ 0x00),\
+  /* Class-Specific AS Interface Descriptor(4.9.2) */\
+  TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_OUTPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ 0x01, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
+  /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
+  TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX),\
+  /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
+  TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN, /*_interval*/ 0x01),\
+  /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
+  TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000),\
+  /* Interface 1, Alternate 2 - alternate interface for data streaming */\
+  TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)((_itfnum)+1), /*_altset*/ 0x02, /*_nEPs*/ 0x01, /*_stridx*/ 0x00),\
+  /* Class-Specific AS Interface Descriptor(4.9.2) */\
+  TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_OUTPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ 0x01, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
+  /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
+  TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_RX),\
+  /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
+  TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_IN, /*_interval*/ 0x01),\
+  /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
+  TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000)
+
+
+#endif
diff --git a/examples/device/board_test/CMakeLists.txt b/examples/device/board_test/CMakeLists.txt
index 37113578e..012eff095 100644
--- a/examples/device/board_test/CMakeLists.txt
+++ b/examples/device/board_test/CMakeLists.txt
@@ -1,42 +1,32 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
-# Check for -DFAMILY=
-if(FAMILY MATCHES "^esp32s[2-3]")
-  # use BOARD-Directory name for project id
-  get_filename_component(PROJECT ${CMAKE_CURRENT_SOURCE_DIR} NAME)
-  set(PROJECT ${BOARD}-${PROJECT})
+# gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
+family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-  # TOP is absolute path to root directory of TinyUSB git repo
-  set(TOP "../../..")
-  get_filename_component(TOP "${TOP}" REALPATH)
+project(${PROJECT} C CXX ASM)
 
-  project(${PROJECT})
+# Checks this example is valid for the family and initializes the project
+family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
-else()
-
-  # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
-  family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
-
-  project(${PROJECT})
-
-  # Checks this example is valid for the family and initializes the project
-  family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
-  add_executable(${PROJECT})
+add_executable(${PROJECT})
 
-  # Example source
-  target_sources(${PROJECT} PUBLIC
-          ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
-          )
+# Example source
+target_sources(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  )
 
-  # Example include
-  target_include_directories(${PROJECT} PUBLIC
-          ${CMAKE_CURRENT_SOURCE_DIR}/src
-          )
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
 
-  # Configure compilation flags and libraries for the example... see the corresponding function
-  # in hw/bsp/FAMILY/family.cmake for details.
-  family_configure_device_example(${PROJECT})
-endif()
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/board_test/Makefile b/examples/device/board_test/Makefile
index b65575ce6..7fa475da5 100644
--- a/examples/device/board_test/Makefile
+++ b/examples/device/board_test/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
@@ -9,10 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-# board_test example is special example that doesn't enable device or host stack
-# This can cause some TinyUSB API missing, this hack to allow us to fill those API
-# to pass the compilation process
-CFLAGS +=	\
-	-D"tud_int_handler(x)= " \
-
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/board_test/src/CMakeLists.txt b/examples/device/board_test/src/CMakeLists.txt
index e4e1f4e9a..8d85dcafd 100644
--- a/examples/device/board_test/src/CMakeLists.txt
+++ b/examples/device/board_test/src/CMakeLists.txt
@@ -1,17 +1,3 @@
-# FAMILY = esp32sx
 idf_component_register(SRCS "main.c"
                     INCLUDE_DIRS "."
-                    REQUIRES freertos soc)
-                    
-file(TO_NATIVE_PATH "${TOP}/hw/bsp/${FAMILY}/boards/${BOARD}/board.cmake" board_cmake)
-
-if(EXISTS ${board_cmake})
-    include(${board_cmake})
-endif()
-
-idf_component_get_property( FREERTOS_ORIG_INCLUDE_PATH freertos ORIG_INCLUDE_PATH)
-target_include_directories(${COMPONENT_TARGET} PUBLIC
-  "${FREERTOS_ORIG_INCLUDE_PATH}"
-  "${TOP}/hw"
-  "${TOP}/src"
-)
+                    REQUIRES boards tinyusb_src)
diff --git a/examples/device/board_test/src/main.c b/examples/device/board_test/src/main.c
index 5e28cbb27..91799eb89 100644
--- a/examples/device/board_test/src/main.c
+++ b/examples/device/board_test/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -26,39 +26,31 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-
-#include "bsp/board.h"
-
-//--------------------------------------------------------------------+
-// MACRO CONSTANT TYPEDEF PROTYPES
-//--------------------------------------------------------------------+
+#include "bsp/board_api.h"
 
 /* Blink pattern
  * - 250 ms  : button is not pressed
  * - 1000 ms : button is pressed (and hold)
  */
-enum  {
+enum {
   BLINK_PRESSED = 250,
   BLINK_UNPRESSED = 1000
 };
 
 #define HELLO_STR   "Hello from TinyUSB\r\n"
 
-int main(void)
-{
+int main(void) {
   board_init();
   board_led_write(true);
 
   uint32_t start_ms = 0;
   bool led_state = false;
 
-  while (1)
-  {
+  while (1) {
     uint32_t interval_ms = board_button_read() ? BLINK_PRESSED : BLINK_UNPRESSED;
 
-    // Blink every interval ms
-    if ( !(board_millis() - start_ms < interval_ms) )
-    {
+    // Blink and print every interval ms
+    if (!(board_millis() - start_ms < interval_ms)) {
       board_uart_write(HELLO_STR, strlen(HELLO_STR));
 
       start_ms = board_millis();
@@ -66,14 +58,17 @@ int main(void)
       board_led_write(led_state);
       led_state = 1 - led_state; // toggle
     }
-  }
 
-  return 0;
+    // echo
+    uint8_t ch;
+    if (board_uart_read(&ch, 1) > 0) {
+      board_uart_write(&ch, 1);
+    }
+  }
 }
 
 #if CFG_TUSB_MCU == OPT_MCU_ESP32S2 || CFG_TUSB_MCU == OPT_MCU_ESP32S3
-void app_main(void)
-{
+void app_main(void) {
   main();
 }
 #endif
diff --git a/examples/device/board_test/src/tusb_config.h b/examples/device/board_test/src/tusb_config.h
index 5aea4fd2c..1a27cc87f 100644
--- a/examples/device/board_test/src/tusb_config.h
+++ b/examples/device/board_test/src/tusb_config.h
@@ -30,6 +30,11 @@
  extern "C" {
 #endif
 
+// board_test example is special example that doesn't enable device or host stack
+// This can cause some TinyUSB API missing, this define hack to allow us to fill those API
+// to pass the compilation process
+#define tud_int_handler(x)
+
 //--------------------------------------------------------------------
 // COMMON CONFIGURATION
 //--------------------------------------------------------------------
@@ -43,6 +48,11 @@
   #define CFG_TUSB_OS               OPT_OS_NONE
 #endif
 
+// Espressif IDF requires "freertos/" prefix in include path
+#if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
+#define CFG_TUSB_OS_INC_PATH  freertos/
+#endif
+
 // This example only test LED & GPIO, disable both device and host stack
 #define CFG_TUD_ENABLED   0
 #define CFG_TUH_ENABLED   0
diff --git a/examples/device/cdc_dual_ports/CMakeLists.txt b/examples/device/cdc_dual_ports/CMakeLists.txt
index abc4d91da..f61e1b640 100644
--- a/examples/device/cdc_dual_ports/CMakeLists.txt
+++ b/examples/device/cdc_dual_ports/CMakeLists.txt
@@ -1,28 +1,33 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
 target_sources(${PROJECT} PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
-        )
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
 
 # Example include
 target_include_directories(${PROJECT} PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src
-        )
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/cdc_dual_ports/Makefile b/examples/device/cdc_dual_ports/Makefile
index 5a455078e..7fa475da5 100644
--- a/examples/device/cdc_dual_ports/Makefile
+++ b/examples/device/cdc_dual_ports/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/cdc_dual_ports/src/main.c b/examples/device/cdc_dual_ports/src/main.c
index 0264f0566..1167a5d50 100644
--- a/examples/device/cdc_dual_ports/src/main.c
+++ b/examples/device/cdc_dual_ports/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -28,44 +28,53 @@
 #include <string.h>
 #include <ctype.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
-//------------- prototypes -------------//
+/* Blink pattern
+ * - 250 ms  : device not mounted
+ * - 1000 ms : device mounted
+ * - 2500 ms : device is suspended
+ */
+enum {
+  BLINK_NOT_MOUNTED = 250,
+  BLINK_MOUNTED = 1000,
+  BLINK_SUSPENDED = 2500,
+};
+
+static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
+
+static void led_blinking_task(void);
 static void cdc_task(void);
 
 /*------------- MAIN -------------*/
-int main(void)
-{
+int main(void) {
   board_init();
 
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
-  while (1)
-  {
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
+  while (1) {
     tud_task(); // tinyusb device task
     cdc_task();
+    led_blinking_task();
   }
-
-  return 0;
 }
 
 // echo to either Serial0 or Serial1
 // with Serial0 as all lower case, Serial1 as all upper case
-static void echo_serial_port(uint8_t itf, uint8_t buf[], uint32_t count)
-{
+static void echo_serial_port(uint8_t itf, uint8_t buf[], uint32_t count) {
   uint8_t const case_diff = 'a' - 'A';
 
-  for(uint32_t i=0; i<count; i++)
-  {
-    if (itf == 0)
-    {
+  for (uint32_t i = 0; i < count; i++) {
+    if (itf == 0) {
       // echo back 1st port as lower case
       if (isupper(buf[i])) buf[i] += case_diff;
-    }
-    else
-    {
+    } else {
       // echo back 2nd port as upper case
       if (islower(buf[i])) buf[i] -= case_diff;
     }
@@ -75,21 +84,29 @@ static void echo_serial_port(uint8_t itf, uint8_t buf[], uint32_t count)
   tud_cdc_n_write_flush(itf);
 }
 
+// Invoked when device is mounted
+void tud_mount_cb(void) {
+  blink_interval_ms = BLINK_MOUNTED;
+}
+
+// Invoked when device is unmounted
+void tud_umount_cb(void) {
+  blink_interval_ms = BLINK_NOT_MOUNTED;
+}
+
+
 //--------------------------------------------------------------------+
 // USB CDC
 //--------------------------------------------------------------------+
-static void cdc_task(void)
-{
+static void cdc_task(void) {
   uint8_t itf;
 
-  for (itf = 0; itf < CFG_TUD_CDC; itf++)
-  {
+  for (itf = 0; itf < CFG_TUD_CDC; itf++) {
     // connected() check for DTR bit
     // Most but not all terminal client set this when making connection
     // if ( tud_cdc_n_connected(itf) )
     {
-      if ( tud_cdc_n_available(itf) )
-      {
+      if (tud_cdc_n_available(itf)) {
         uint8_t buf[64];
 
         uint32_t count = tud_cdc_n_read(itf, buf, sizeof(buf));
@@ -101,3 +118,18 @@ static void cdc_task(void)
     }
   }
 }
+
+//--------------------------------------------------------------------+
+// BLINKING TASK
+//--------------------------------------------------------------------+
+void led_blinking_task(void) {
+  static uint32_t start_ms = 0;
+  static bool led_state = false;
+
+  // Blink every interval ms
+  if (board_millis() - start_ms < blink_interval_ms) return; // not enough time
+  start_ms += blink_interval_ms;
+
+  board_led_write(led_state);
+  led_state = 1 - led_state; // toggle
+}
diff --git a/examples/device/cdc_dual_ports/src/usb_descriptors.c b/examples/device/cdc_dual_ports/src/usb_descriptors.c
index cda1b63b6..de2505c07 100644
--- a/examples/device/cdc_dual_ports/src/usb_descriptors.c
+++ b/examples/device/cdc_dual_ports/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,13 +23,14 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
  * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
  *
  * Auto ProductID layout's Bitmap:
- *   [MSB]       MIDI | HID | MSC | CDC          [LSB]
+ *   [MSB]         HID | MSC | CDC          [LSB]
  */
 #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
@@ -108,6 +109,17 @@ enum
   #define EPNUM_CDC_1_OUT     0x05
   #define EPNUM_CDC_1_IN      0x86
 
+#elif CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X
+  // FT9XX doesn't support a same endpoint number with different direction IN and OUT
+  //    e.g EP1 OUT & EP1 IN cannot exist together
+  #define EPNUM_CDC_0_NOTIF   0x81
+  #define EPNUM_CDC_0_OUT     0x02
+  #define EPNUM_CDC_0_IN      0x83
+
+  #define EPNUM_CDC_1_NOTIF   0x84
+  #define EPNUM_CDC_1_OUT     0x05
+  #define EPNUM_CDC_1_IN      0x86
+
 #else
   #define EPNUM_CDC_0_NOTIF   0x81
   #define EPNUM_CDC_0_OUT     0x02
@@ -202,52 +214,64 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
   "TinyUSB CDC",                 // 4: CDC Interface
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/cdc_msc/CMakeLists.txt b/examples/device/cdc_msc/CMakeLists.txt
index fa6e83b7e..9415f8c68 100644
--- a/examples/device/cdc_msc/CMakeLists.txt
+++ b/examples/device/cdc_msc/CMakeLists.txt
@@ -1,29 +1,35 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
+set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
 target_sources(${PROJECT} PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/msc_disk.c
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
-        )
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/msc_disk.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
 
 # Example include
 target_include_directories(${PROJECT} PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src
-        )
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
 
 # Configure compilation flags and libraries for the example... see the corresponding function
 # in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/cdc_msc/Makefile b/examples/device/cdc_msc/Makefile
index 69b633fea..0c2e37180 100644
--- a/examples/device/cdc_msc/Makefile
+++ b/examples/device/cdc_msc/Makefile
@@ -1,12 +1,15 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
 	$(TOP)/hw \
 
 # Example source
-EXAMPLE_SOURCE += $(wildcard src/*.c)
+EXAMPLE_SOURCE += \
+  src/main.c \
+  src/msc_disk.c \
+  src/usb_descriptors.c \
+
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/cdc_msc/skip.txt b/examples/device/cdc_msc/skip.txt
index d844feae8..833fd072c 100644
--- a/examples/device/cdc_msc/skip.txt
+++ b/examples/device/cdc_msc/skip.txt
@@ -1 +1,2 @@
-mcu:SAMD11
\ No newline at end of file
+mcu:SAMD11
+family:espressif
diff --git a/examples/device/cdc_msc/src/main.c b/examples/device/cdc_msc/src/main.c
index c3666763b..0d3f97c8f 100644
--- a/examples/device/cdc_msc/src/main.c
+++ b/examples/device/cdc_msc/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 //--------------------------------------------------------------------+
@@ -39,7 +39,7 @@
  * - 1000 ms : device mounted
  * - 2500 ms : device is suspended
  */
-enum  {
+enum {
   BLINK_NOT_MOUNTED = 250,
   BLINK_MOUNTED = 1000,
   BLINK_SUSPENDED = 2500,
@@ -51,22 +51,22 @@ void led_blinking_task(void);
 void cdc_task(void);
 
 /*------------- MAIN -------------*/
-int main(void)
-{
+int main(void) {
   board_init();
 
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
-  while (1)
-  {
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
+  while (1) {
     tud_task(); // tinyusb device task
     led_blinking_task();
 
     cdc_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -74,46 +74,40 @@ int main(void)
 //--------------------------------------------------------------------+
 
 // Invoked when device is mounted
-void tud_mount_cb(void)
-{
+void tud_mount_cb(void) {
   blink_interval_ms = BLINK_MOUNTED;
 }
 
 // Invoked when device is unmounted
-void tud_umount_cb(void)
-{
+void tud_umount_cb(void) {
   blink_interval_ms = BLINK_NOT_MOUNTED;
 }
 
 // Invoked when usb bus is suspended
 // remote_wakeup_en : if host allow us  to perform remote wakeup
 // Within 7ms, device must draw an average of current less than 2.5 mA from bus
-void tud_suspend_cb(bool remote_wakeup_en)
-{
+void tud_suspend_cb(bool remote_wakeup_en) {
   (void) remote_wakeup_en;
   blink_interval_ms = BLINK_SUSPENDED;
 }
 
 // Invoked when usb bus is resumed
-void tud_resume_cb(void)
-{
-  blink_interval_ms = BLINK_MOUNTED;
+void tud_resume_cb(void) {
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 
 //--------------------------------------------------------------------+
 // USB CDC
 //--------------------------------------------------------------------+
-void cdc_task(void)
-{
+void cdc_task(void) {
   // connected() check for DTR bit
   // Most but not all terminal client set this when making connection
   // if ( tud_cdc_connected() )
   {
     // connected and there are data available
-    if ( tud_cdc_available() )
-    {
-      // read datas
+    if (tud_cdc_available()) {
+      // read data
       char buf[64];
       uint32_t count = tud_cdc_read(buf, sizeof(buf));
       (void) count;
@@ -129,37 +123,32 @@ void cdc_task(void)
 }
 
 // Invoked when cdc when line state changed e.g connected/disconnected
-void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts)
-{
+void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
   (void) itf;
   (void) rts;
 
   // TODO set some indicator
-  if ( dtr )
-  {
+  if (dtr) {
     // Terminal connected
-  }else
-  {
+  } else {
     // Terminal disconnected
   }
 }
 
 // Invoked when CDC interface received data from host
-void tud_cdc_rx_cb(uint8_t itf)
-{
+void tud_cdc_rx_cb(uint8_t itf) {
   (void) itf;
 }
 
 //--------------------------------------------------------------------+
 // BLINKING TASK
 //--------------------------------------------------------------------+
-void led_blinking_task(void)
-{
+void led_blinking_task(void) {
   static uint32_t start_ms = 0;
   static bool led_state = false;
 
   // Blink every interval ms
-  if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
+  if (board_millis() - start_ms < blink_interval_ms) return; // not enough time
   start_ms += blink_interval_ms;
 
   board_led_write(led_state);
diff --git a/examples/device/cdc_msc/src/msc_disk.c b/examples/device/cdc_msc/src/msc_disk.c
index e67e381ce..d2f8628f1 100644
--- a/examples/device/cdc_msc/src/msc_disk.c
+++ b/examples/device/cdc_msc/src/msc_disk.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,7 +23,7 @@
  *
  */
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #if CFG_TUD_MSC
diff --git a/examples/device/cdc_msc/src/usb_descriptors.c b/examples/device/cdc_msc/src/usb_descriptors.c
index 6b59ed50f..2afa24903 100644
--- a/examples/device/cdc_msc/src/usb_descriptors.c
+++ b/examples/device/cdc_msc/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -41,35 +42,33 @@
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
-tusb_desc_device_t const desc_device =
-{
-  .bLength            = sizeof(tusb_desc_device_t),
-  .bDescriptorType    = TUSB_DESC_DEVICE,
-  .bcdUSB             = USB_BCD,
+tusb_desc_device_t const desc_device = {
+    .bLength            = sizeof(tusb_desc_device_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bcdUSB             = USB_BCD,
 
-  // Use Interface Association Descriptor (IAD) for CDC
-  // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
-  .bDeviceClass       = TUSB_CLASS_MISC,
-  .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
-  .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+    // Use Interface Association Descriptor (IAD) for CDC
+    // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
 
-  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
-  .idVendor           = USB_VID,
-  .idProduct          = USB_PID,
-  .bcdDevice          = 0x0100,
+    .idVendor           = USB_VID,
+    .idProduct          = USB_PID,
+    .bcdDevice          = 0x0100,
 
-  .iManufacturer      = 0x01,
-  .iProduct           = 0x02,
-  .iSerialNumber      = 0x03,
+    .iManufacturer      = 0x01,
+    .iProduct           = 0x02,
+    .iSerialNumber      = 0x03,
 
-  .bNumConfigurations = 0x01
+    .bNumConfigurations = 0x01
 };
 
 // Invoked when received GET DEVICE DESCRIPTOR
 // Application return pointer to descriptor
-uint8_t const * tud_descriptor_device_cb(void)
-{
+uint8_t const *tud_descriptor_device_cb(void) {
   return (uint8_t const *) &desc_device;
 }
 
@@ -77,8 +76,7 @@ uint8_t const * tud_descriptor_device_cb(void)
 // Configuration Descriptor
 //--------------------------------------------------------------------+
 
-enum
-{
+enum {
   ITF_NUM_CDC = 0,
   ITF_NUM_CDC_DATA,
   ITF_NUM_MSC,
@@ -95,7 +93,7 @@ enum
   #define EPNUM_MSC_OUT     0x05
   #define EPNUM_MSC_IN      0x85
 
-#elif CFG_TUSB_MCU == OPT_MCU_SAMG  || CFG_TUSB_MCU ==  OPT_MCU_SAMX7X
+#elif CFG_TUSB_MCU == OPT_MCU_SAMG || CFG_TUSB_MCU == OPT_MCU_SAMX7X
   // SAMG & SAME70 don't support a same endpoint number with different direction IN and OUT
   //    e.g EP1 OUT & EP1 IN cannot exist together
   #define EPNUM_CDC_NOTIF   0x81
@@ -140,67 +138,62 @@ enum
 #define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_MSC_DESC_LEN)
 
 // full speed configuration
-uint8_t const desc_fs_configuration[] =
-{
-  // Config number, interface count, string index, total length, attribute, power in mA
-  TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
+uint8_t const desc_fs_configuration[] = {
+    // Config number, interface count, string index, total length, attribute, power in mA
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
 
-  // Interface number, string index, EP notification address and size, EP data address (out, in) and size.
-  TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64),
+    // Interface number, string index, EP notification address and size, EP data address (out, in) and size.
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64),
 
-  // Interface number, string index, EP Out & EP In address, EP size
-  TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 5, EPNUM_MSC_OUT, EPNUM_MSC_IN, 64),
+    // Interface number, string index, EP Out & EP In address, EP size
+    TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 5, EPNUM_MSC_OUT, EPNUM_MSC_IN, 64),
 };
 
 #if TUD_OPT_HIGH_SPEED
 // Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
 
 // high speed configuration
-uint8_t const desc_hs_configuration[] =
-{
-  // Config number, interface count, string index, total length, attribute, power in mA
-  TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
+uint8_t const desc_hs_configuration[] = {
+    // Config number, interface count, string index, total length, attribute, power in mA
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
 
-  // Interface number, string index, EP notification address and size, EP data address (out, in) and size.
-  TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 512),
+    // Interface number, string index, EP notification address and size, EP data address (out, in) and size.
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 512),
 
-  // Interface number, string index, EP Out & EP In address, EP size
-  TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 5, EPNUM_MSC_OUT, EPNUM_MSC_IN, 512),
+    // Interface number, string index, EP Out & EP In address, EP size
+    TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 5, EPNUM_MSC_OUT, EPNUM_MSC_IN, 512),
 };
 
 // other speed configuration
 uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];
 
 // device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
-tusb_desc_device_qualifier_t const desc_device_qualifier =
-{
-  .bLength            = sizeof(tusb_desc_device_qualifier_t),
-  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
-  .bcdUSB             = USB_BCD,
+tusb_desc_device_qualifier_t const desc_device_qualifier = {
+    .bLength            = sizeof(tusb_desc_device_qualifier_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
+    .bcdUSB             = USB_BCD,
 
-  .bDeviceClass       = TUSB_CLASS_MISC,
-  .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
-  .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
 
-  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
-  .bNumConfigurations = 0x01,
-  .bReserved          = 0x00
+    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+    .bNumConfigurations = 0x01,
+    .bReserved          = 0x00
 };
 
 // Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
 // device_qualifier descriptor describes information about a high-speed capable device that would
 // change if the device were operating at the other speed. If not highspeed capable stall this request.
-uint8_t const* tud_descriptor_device_qualifier_cb(void)
-{
-  return (uint8_t const*) &desc_device_qualifier;
+uint8_t const *tud_descriptor_device_qualifier_cb(void) {
+  return (uint8_t const *) &desc_device_qualifier;
 }
 
 // Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
 // Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
-uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index)
-{
+uint8_t const *tud_descriptor_other_speed_configuration_cb(uint8_t index) {
   (void) index; // for multiple configurations
 
   // if link speed is high return fullspeed config, and vice versa
@@ -220,13 +213,12 @@ uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index)
 // Invoked when received GET CONFIGURATION DESCRIPTOR
 // Application return pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete
-uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
-{
+uint8_t const *tud_descriptor_configuration_cb(uint8_t index) {
   (void) index; // for multiple configurations
 
 #if TUD_OPT_HIGH_SPEED
   // Although we are highspeed, host may be fullspeed.
-  return (tud_speed_get() == TUSB_SPEED_HIGH) ?  desc_hs_configuration : desc_fs_configuration;
+  return (tud_speed_get() == TUSB_SPEED_HIGH) ? desc_hs_configuration : desc_fs_configuration;
 #else
   return desc_fs_configuration;
 #endif
@@ -236,53 +228,64 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
-{
-  (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
-  "TinyUSB",                     // 1: Manufacturer
-  "TinyUSB Device",              // 2: Product
-  "123456789012",                // 3: Serials, should use chip ID
-  "TinyUSB CDC",                 // 4: CDC Interface
-  "TinyUSB MSC",                 // 5: MSC Interface
+char const *string_desc_arr[] = {
+    (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
+    "TinyUSB",                     // 1: Manufacturer
+    "TinyUSB Device",              // 2: Product
+    NULL,                          // 3: Serials will use unique ID if possible
+    "TinyUSB CDC",                 // 4: CDC Interface
+    "TinyUSB MSC",                 // 5: MSC Interface
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/cdc_msc_freertos/CMakeLists.txt b/examples/device/cdc_msc_freertos/CMakeLists.txt
index 639dde99a..33c7a1ec0 100644
--- a/examples/device/cdc_msc_freertos/CMakeLists.txt
+++ b/examples/device/cdc_msc_freertos/CMakeLists.txt
@@ -1,22 +1,35 @@
-cmake_minimum_required(VERSION 3.5)
-
-# TOP is absolute path to root directory of TinyUSB git repo
-# needed for esp32sx build. TOOD could be removed later on
-set(TOP "../../..")
-get_filename_component(TOP "${TOP}" REALPATH)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
-# Check for -DFAMILY=
-if(FAMILY MATCHES "^esp32s[2-3]")
-else()
-  message(FATAL_ERROR "Invalid FAMILY specified: ${FAMILY}")
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
 endif()
+
+add_executable(${PROJECT})
+
+# Example source
+target_sources(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/freertos_hook.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/msc_disk.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
+
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
+
+# Configure compilation flags and libraries for the example with FreeRTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} freertos)
diff --git a/examples/device/cdc_msc_freertos/Makefile b/examples/device/cdc_msc_freertos/Makefile
index 3352dd37d..13f336f99 100644
--- a/examples/device/cdc_msc_freertos/Makefile
+++ b/examples/device/cdc_msc_freertos/Makefile
@@ -1,17 +1,15 @@
-DEPS_SUBMODULES += lib/FreeRTOS-Kernel
-
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 FREERTOS_SRC = lib/FreeRTOS-Kernel
+FREERTOS_PORTABLE_PATH= $(FREERTOS_SRC)/portable/$(if $(USE_IAR),IAR,GCC)
 
 INC += \
 	src \
 	src/FreeRTOSConfig \
 	$(TOP)/hw \
 	$(TOP)/$(FREERTOS_SRC)/include \
-	$(TOP)/$(FREERTOS_SRC)/portable/GCC/$(FREERTOS_PORT)
-	
+	$(TOP)/$(FREERTOS_PORTABLE_SRC) \
+
 # Example source
 EXAMPLE_SOURCE = \
 	src/freertos_hook.c \
@@ -27,12 +25,22 @@ SRC_C += \
 	$(FREERTOS_SRC)/queue.c \
 	$(FREERTOS_SRC)/tasks.c \
 	$(FREERTOS_SRC)/timers.c \
-	$(subst ../../../,,$(wildcard ../../../$(FREERTOS_SRC)/portable/GCC/$(FREERTOS_PORT)/*.c))
+	$(subst $(TOP)/,,$(wildcard $(TOP)/$(FREERTOS_PORTABLE_SRC)/*.c))
+
+SRC_S += \
+	$(subst $(TOP)/,,$(wildcard $(TOP)/$(FREERTOS_PORTABLE_SRC)/*.s))
+
+# include heap manage if configSUPPORT_DYNAMIC_ALLOCATION = 1
+# SRC_C += $(FREERTOS_SRC)/portable/MemMang/heap_1.c
+# CFLAGS += -Wno-error=sign-compare
+
+# Suppress FreeRTOSConfig.h warnings
+CFLAGS_GCC += -Wno-error=redundant-decls
 
-# Suppress FreeRTOS warnings
-CFLAGS += -Wno-error=cast-qual -Wno-error=redundant-decls
+# Suppress FreeRTOS source warnings
+CFLAGS_GCC += -Wno-error=cast-qual
 
 # FreeRTOS (lto + Os) linker issue
-LDFLAGS += -Wl,--undefined=vTaskSwitchContext
+LDFLAGS_GCC += -Wl,--undefined=vTaskSwitchContext
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/cdc_msc_freertos/skip.txt b/examples/device/cdc_msc_freertos/skip.txt
index 1ee51a9d4..a6f96b288 100644
--- a/examples/device/cdc_msc_freertos/skip.txt
+++ b/examples/device/cdc_msc_freertos/skip.txt
@@ -1,3 +1,4 @@
+mcu:CH32V307
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103
@@ -7,5 +8,6 @@ mcu:RP2040
 mcu:SAMD11
 mcu:SAMX7X
 mcu:VALENTYUSB_EPTRI
+mcu:RAXXX
 family:broadcom_32bit
-family:broadcom_64bit
\ No newline at end of file
+family:broadcom_64bit
diff --git a/examples/device/cdc_msc_freertos/src/CMakeLists.txt b/examples/device/cdc_msc_freertos/src/CMakeLists.txt
index 9216e2b49..fee264363 100644
--- a/examples/device/cdc_msc_freertos/src/CMakeLists.txt
+++ b/examples/device/cdc_msc_freertos/src/CMakeLists.txt
@@ -1,35 +1,4 @@
+# This file is for ESP-IDF only
 idf_component_register(SRCS "main.c" "usb_descriptors.c" "msc_disk.c"
                     INCLUDE_DIRS "."
-                    REQUIRES freertos soc)
-
-file(TO_NATIVE_PATH "${TOP}/hw/bsp/${FAMILY}/boards/${BOARD}/board.cmake" board_cmake)
-
-if(EXISTS ${board_cmake})
-    include(${board_cmake})
-endif()
-
-target_include_directories(${COMPONENT_TARGET} PUBLIC
-  "${TOP}/hw"
-  "${TOP}/src"
-)
-
-target_compile_definitions(${COMPONENT_TARGET} PUBLIC
-  ESP_PLATFORM
-)
-
-target_sources(${COMPONENT_TARGET} PUBLIC
-  "${TOP}/src/tusb.c"
-  "${TOP}/src/common/tusb_fifo.c"
-  "${TOP}/src/device/usbd.c"
-  "${TOP}/src/device/usbd_control.c"
-  "${TOP}/src/class/cdc/cdc_device.c"
-  "${TOP}/src/class/dfu/dfu_rt_device.c"
-  "${TOP}/src/class/hid/hid_device.c"
-  "${TOP}/src/class/midi/midi_device.c"
-  "${TOP}/src/class/msc/msc_device.c"
-  "${TOP}/src/class/net/ecm_rndis_device.c"
-  "${TOP}/src/class/net/ncm_device.c"
-  "${TOP}/src/class/usbtmc/usbtmc_device.c"
-  "${TOP}/src/class/vendor/vendor_device.c"
-  "${TOP}/src/portable/synopsys/dwc2/dcd_dwc2.c"
-)
+                    REQUIRES boards tinyusb_src)
diff --git a/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h b/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
index 6a3630dbc..6cc7a6577 100644
--- a/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
+++ b/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
@@ -42,6 +42,9 @@
  * See http://www.freertos.org/a00110.html.
  *----------------------------------------------------------*/
 
+// skip if included from IAR assembler
+#ifndef __IASMARM__
+
 // Include MCU header
 #include "bsp/board_mcu.h"
 
@@ -57,6 +60,8 @@
   extern uint32_t SystemCoreClock;
 #endif
 
+#endif
+
 /* Cortex M23/M33 port configuration. */
 #define configENABLE_MPU								        0
 #define configENABLE_FPU								        1
@@ -69,14 +74,14 @@
 #define configTICK_RATE_HZ                      ( 1000 )
 #define configMAX_PRIORITIES                    ( 5 )
 #define configMINIMAL_STACK_SIZE                ( 128 )
-#define configTOTAL_HEAP_SIZE                   ( 0*1024 ) // dynamic is not used
+#define configTOTAL_HEAP_SIZE                   ( configSUPPORT_DYNAMIC_ALLOCATION*4*1024 )
 #define configMAX_TASK_NAME_LEN                 16
 #define configUSE_16_BIT_TICKS                  0
 #define configIDLE_SHOULD_YIELD                 1
 #define configUSE_MUTEXES                       1
 #define configUSE_RECURSIVE_MUTEXES             1
 #define configUSE_COUNTING_SEMAPHORES           1
-#define configQUEUE_REGISTRY_SIZE               2
+#define configQUEUE_REGISTRY_SIZE               4
 #define configUSE_QUEUE_SETS                    0
 #define configUSE_TIME_SLICING                  0
 #define configUSE_NEWLIB_REENTRANT              0
@@ -91,6 +96,7 @@
 #define configUSE_TICK_HOOK                    0
 #define configUSE_MALLOC_FAILED_HOOK           0 // cause nested extern warning
 #define configCHECK_FOR_STACK_OVERFLOW         2
+#define configCHECK_HANDLER_INSTALLATION       0
 
 /* Run time and task stats gathering related definitions. */
 #define configGENERATE_RUN_TIME_STATS          0
@@ -125,29 +131,12 @@
 #define INCLUDE_xEventGroupSetBitFromISR       0
 #define INCLUDE_xTimerPendFunctionCall         0
 
-/* Define to trap errors during development. */
-// Halt CPU (breakpoint) when hitting error, only apply for Cortex M3, M4, M7
-#if defined(__ARM_ARCH_7M__) || defined (__ARM_ARCH_7EM__)
-  #define configASSERT(_exp) \
-    do {\
-      if ( !(_exp) ) { \
-        volatile uint32_t* ARM_CM_DHCSR =  ((volatile uint32_t*) 0xE000EDF0UL); /* Cortex M CoreDebug->DHCSR */ \
-        if ( (*ARM_CM_DHCSR) & 1UL ) {  /* Only halt mcu if debugger is attached */ \
-          taskDISABLE_INTERRUPTS(); \
-           __asm("BKPT #0\n"); \
-        }\
-      }\
-    } while(0)
-#else
-  #define configASSERT( x )
-#endif
-
 #ifdef __RX__
 /* Renesas RX series */
-#define vSoftwareInterruptISR					INT_Excep_ICU_SWINT
-#define vTickISR								INT_Excep_CMT0_CMI0
-#define configPERIPHERAL_CLOCK_HZ				(configCPU_CLOCK_HZ/2)
-#define configKERNEL_INTERRUPT_PRIORITY			1
+#define vSoftwareInterruptISR					        INT_Excep_ICU_SWINT
+#define vTickISR								              INT_Excep_CMT0_CMI0
+#define configPERIPHERAL_CLOCK_HZ				      (configCPU_CLOCK_HZ/2)
+#define configKERNEL_INTERRUPT_PRIORITY			  1
 #define configMAX_SYSCALL_INTERRUPT_PRIORITY	4
 
 #else
@@ -163,9 +152,18 @@
 #if defined(__NVIC_PRIO_BITS)
   // For Cortex-M specific: __NVIC_PRIO_BITS is defined in core_cmx.h
 	#define configPRIO_BITS       __NVIC_PRIO_BITS
+
 #elif defined(__ECLIC_INTCTLBITS)
   // RISC-V Bumblebee core from nuclei
   #define configPRIO_BITS       __ECLIC_INTCTLBITS
+
+#elif defined(__IASMARM__)
+  // FIXME: IAR Assembler cannot include mcu header directly to get __NVIC_PRIO_BITS.
+  // Therefore we will hard coded it to minimum value of 2 to get pass ci build.
+  // IAR user must update this to correct value of the target MCU
+  #message "configPRIO_BITS is hard coded to 2 to pass IAR build only. User should update it per MCU"
+  #define configPRIO_BITS       2
+
 #else
   #error "FreeRTOS configPRIO_BITS to be defined"
 #endif
diff --git a/examples/device/cdc_msc_freertos/src/main.c b/examples/device/cdc_msc_freertos/src/main.c
index 755220c13..e94e8eaec 100644
--- a/examples/device/cdc_msc_freertos/src/main.c
+++ b/examples/device/cdc_msc_freertos/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
@@ -41,6 +41,7 @@
 
   #define USBD_STACK_SIZE     4096
 #else
+
   #include "FreeRTOS.h"
   #include "semphr.h"
   #include "queue.h"
@@ -51,8 +52,11 @@
   #define USBD_STACK_SIZE    (3*configMINIMAL_STACK_SIZE/2) * (CFG_TUSB_DEBUG ? 2 : 1)
 #endif
 
+#define CDC_STACK_SIZE      configMINIMAL_STACK_SIZE
+#define BLINKY_STACK_SIZE   configMINIMAL_STACK_SIZE
+
 //--------------------------------------------------------------------+
-// MACRO CONSTANT TYPEDEF PROTYPES
+// MACRO CONSTANT TYPEDEF PROTOTYPES
 //--------------------------------------------------------------------+
 
 /* Blink pattern
@@ -60,47 +64,51 @@
  * - 1000 ms : device mounted
  * - 2500 ms : device is suspended
  */
-enum  {
+enum {
   BLINK_NOT_MOUNTED = 250,
   BLINK_MOUNTED = 1000,
   BLINK_SUSPENDED = 2500,
 };
 
-// static timer
-StaticTimer_t blinky_tmdef;
-TimerHandle_t blinky_tm;
-
 // static task
+#if configSUPPORT_STATIC_ALLOCATION
+StackType_t blinky_stack[BLINKY_STACK_SIZE];
+StaticTask_t blinky_taskdef;
+
 StackType_t  usb_device_stack[USBD_STACK_SIZE];
 StaticTask_t usb_device_taskdef;
 
-// static task for cdc
-#define CDC_STACK_SZIE      configMINIMAL_STACK_SIZE
-StackType_t  cdc_stack[CDC_STACK_SZIE];
+StackType_t  cdc_stack[CDC_STACK_SIZE];
 StaticTask_t cdc_taskdef;
+#endif
 
+static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
 
-void led_blinky_cb(TimerHandle_t xTimer);
-void usb_device_task(void* param);
-void cdc_task(void* params);
+static void usb_device_task(void *param);
+void led_blinking_task(void* param);
+void cdc_task(void *params);
 
 //--------------------------------------------------------------------+
 // Main
 //--------------------------------------------------------------------+
 
-int main(void)
-{
+int main(void) {
   board_init();
 
-  // soft timer for blinky
-  blinky_tm = xTimerCreateStatic(NULL, pdMS_TO_TICKS(BLINK_NOT_MOUNTED), true, NULL, led_blinky_cb, &blinky_tmdef);
-  xTimerStart(blinky_tm, 0);
+#if configSUPPORT_STATIC_ALLOCATION
+  // blinky task
+  xTaskCreateStatic(led_blinking_task, "blinky", BLINKY_STACK_SIZE, NULL, 1, blinky_stack, &blinky_taskdef);
 
   // Create a task for tinyusb device stack
-  (void) xTaskCreateStatic( usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);
+  xTaskCreateStatic(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);
 
   // Create CDC task
-  (void) xTaskCreateStatic( cdc_task, "cdc", CDC_STACK_SZIE, NULL, configMAX_PRIORITIES-2, cdc_stack, &cdc_taskdef);
+  xTaskCreateStatic(cdc_task, "cdc", CDC_STACK_SIZE, NULL, configMAX_PRIORITIES - 2, cdc_stack, &cdc_taskdef);
+#else
+  xTaskCreate(led_blinking_task, "blinky", BLINKY_STACK_SIZE, NULL, 1, NULL);
+  xTaskCreate(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, NULL);
+  xTaskCreate(cdc_task, "cdc", CDC_STACK_SZIE, NULL, configMAX_PRIORITIES - 2, NULL);
+#endif
 
   // skip starting scheduler (and return) for ESP32-S2 or ESP32-S3
 #if !TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
@@ -111,16 +119,14 @@ int main(void)
 }
 
 #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
-void app_main(void)
-{
+void app_main(void) {
   main();
 }
 #endif
 
 // USB Device Driver task
 // This top level thread process all usb events and invoke callbacks
-void usb_device_task(void* param)
-{
+static void usb_device_task(void *param) {
   (void) param;
 
   // init device stack on configured roothub port
@@ -128,9 +134,12 @@ void usb_device_task(void* param)
   // Otherwise it could cause kernel issue since USB IRQ handler does use RTOS queue API.
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   // RTOS forever loop
-  while (1)
-  {
+  while (1) {
     // put this thread to waiting state until there is new events
     tud_task();
 
@@ -144,49 +153,42 @@ void usb_device_task(void* param)
 //--------------------------------------------------------------------+
 
 // Invoked when device is mounted
-void tud_mount_cb(void)
-{
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_MOUNTED), 0);
+void tud_mount_cb(void) {
+  blink_interval_ms = BLINK_MOUNTED;
 }
 
 // Invoked when device is unmounted
-void tud_umount_cb(void)
-{
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_NOT_MOUNTED), 0);
+void tud_umount_cb(void) {
+  blink_interval_ms = BLINK_NOT_MOUNTED;
 }
 
 // Invoked when usb bus is suspended
 // remote_wakeup_en : if host allow us  to perform remote wakeup
 // Within 7ms, device must draw an average of current less than 2.5 mA from bus
-void tud_suspend_cb(bool remote_wakeup_en)
-{
+void tud_suspend_cb(bool remote_wakeup_en) {
   (void) remote_wakeup_en;
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_SUSPENDED), 0);
+  blink_interval_ms = BLINK_SUSPENDED;
 }
 
 // Invoked when usb bus is resumed
-void tud_resume_cb(void)
-{
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_MOUNTED), 0);
+void tud_resume_cb(void) {
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
 // USB CDC
 //--------------------------------------------------------------------+
-void cdc_task(void* params)
-{
+void cdc_task(void *params) {
   (void) params;
 
   // RTOS forever loop
-  while ( 1 )
-  {
+  while (1) {
     // connected() check for DTR bit
     // Most but not all terminal client set this when making connection
     // if ( tud_cdc_connected() )
     {
       // There are data available
-      while ( tud_cdc_available() )
-      {
+      while (tud_cdc_available()) {
         uint8_t buf[64];
 
         // read and echo back
@@ -209,35 +211,37 @@ void cdc_task(void* params)
 }
 
 // Invoked when cdc when line state changed e.g connected/disconnected
-void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts)
-{
+void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
   (void) itf;
   (void) rts;
 
   // TODO set some indicator
-  if ( dtr )
-  {
+  if (dtr) {
     // Terminal connected
-  }else
-  {
+  } else {
     // Terminal disconnected
   }
 }
 
 // Invoked when CDC interface received data from host
-void tud_cdc_rx_cb(uint8_t itf)
-{
+void tud_cdc_rx_cb(uint8_t itf) {
   (void) itf;
 }
 
 //--------------------------------------------------------------------+
 // BLINKING TASK
 //--------------------------------------------------------------------+
-void led_blinky_cb(TimerHandle_t xTimer)
-{
-  (void) xTimer;
+void led_blinking_task(void* param) {
+  (void) param;
+  static uint32_t start_ms = 0;
   static bool led_state = false;
 
-  board_led_write(led_state);
-  led_state = 1 - led_state; // toggle
+  while (1) {
+    // Blink every interval ms
+    vTaskDelay(blink_interval_ms / portTICK_PERIOD_MS);
+    start_ms += blink_interval_ms;
+
+    board_led_write(led_state);
+    led_state = 1 - led_state; // toggle
+  }
 }
diff --git a/examples/device/cdc_msc_freertos/src/msc_disk.c b/examples/device/cdc_msc_freertos/src/msc_disk.c
index a895f4738..c8a04bb74 100644
--- a/examples/device/cdc_msc_freertos/src/msc_disk.c
+++ b/examples/device/cdc_msc_freertos/src/msc_disk.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,7 +23,7 @@
  *
  */
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #if CFG_TUD_MSC
@@ -184,7 +184,7 @@ int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buff
   uint8_t const* addr = msc_disk[lba] + offset;
   memcpy(buffer, addr, bufsize);
 
-  return bufsize;
+  return (int32_t) bufsize;
 }
 
 // Callback invoked when received WRITE10 command.
@@ -203,7 +203,7 @@ int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t*
   (void) lba; (void) offset; (void) buffer;
 #endif
 
-  return bufsize;
+  return (int32_t) bufsize;
 }
 
 // Callback invoked when received an SCSI command not in built-in list below
@@ -237,14 +237,14 @@ int32_t tud_msc_scsi_cb (uint8_t lun, uint8_t const scsi_cmd[16], void* buffer,
   {
     if(in_xfer)
     {
-      memcpy(buffer, response, resplen);
+      memcpy(buffer, response, (size_t) resplen);
     }else
     {
       // SCSI output
     }
   }
 
-  return resplen;
+  return (int32_t) resplen;
 }
 
 #endif
diff --git a/examples/device/cdc_msc_freertos/src/tusb_config.h b/examples/device/cdc_msc_freertos/src/tusb_config.h
index 0ec8896b9..91efe7d40 100644
--- a/examples/device/cdc_msc_freertos/src/tusb_config.h
+++ b/examples/device/cdc_msc_freertos/src/tusb_config.h
@@ -54,7 +54,9 @@
 #endif
 
 // This examples use FreeRTOS
+#ifndef CFG_TUSB_OS
 #define CFG_TUSB_OS           OPT_OS_FREERTOS
+#endif
 
 // Espressif IDF requires "freertos/" prefix in include path
 #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
diff --git a/examples/device/cdc_msc_freertos/src/usb_descriptors.c b/examples/device/cdc_msc_freertos/src/usb_descriptors.c
index 30a712275..9c29701c7 100644
--- a/examples/device/cdc_msc_freertos/src/usb_descriptors.c
+++ b/examples/device/cdc_msc_freertos/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -212,53 +213,65 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456789012",                // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
   "TinyUSB CDC",                 // 4: CDC Interface
   "TinyUSB MSC",                 // 5: MSC Interface
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/cdc_uac2/CMakeLists.txt b/examples/device/cdc_uac2/CMakeLists.txt
new file mode 100644
index 000000000..64e4374e9
--- /dev/null
+++ b/examples/device/cdc_uac2/CMakeLists.txt
@@ -0,0 +1,38 @@
+cmake_minimum_required(VERSION 3.17)
+
+include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
+
+# gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
+family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
+
+project(${PROJECT} C CXX ASM)
+
+# Checks this example is valid for the family and initializes the project
+family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
+add_executable(${PROJECT})
+
+# Example source
+target_sources(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/cdc_app.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/uac2_app.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
+
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
+
+# Configure compilation flags and libraries for the example... see the corresponding function
+# in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
+
+# Uncomment me to enable UART based debugging
+# pico_enable_stdio_uart(${PROJECT} 1)
diff --git a/examples/device/cdc_uac2/Makefile b/examples/device/cdc_uac2/Makefile
new file mode 100644
index 000000000..21dcdb0b2
--- /dev/null
+++ b/examples/device/cdc_uac2/Makefile
@@ -0,0 +1,16 @@
+include ../../build_system/make/make.mk
+
+INC += \
+	src \
+	$(TOP)/hw \
+
+# Example source
+EXAMPLE_SOURCE += \
+  src/cdc_app.c \
+  src/main.c \
+  src/uac2_app.c \
+  src/usb_descriptors.c \
+
+SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
+
+include ../../build_system/make/rules.mk
diff --git a/examples/device/cdc_uac2/README.md b/examples/device/cdc_uac2/README.md
new file mode 100644
index 000000000..5d120be7d
--- /dev/null
+++ b/examples/device/cdc_uac2/README.md
@@ -0,0 +1,52 @@
+#### Composite CDC + UAC2 on Pico
+
+This example provides a composite CDC + UAC2 device on top of a Raspberry Pi
+Pico board.
+
+
+#### Use Cases
+
+- The CDC + UAC2 composite device happens to be important, especially in the
+  amateur radio community.
+
+  Modern radios (`rigs`) like Icom IC-7300 + IC-705 expose a sound card and a
+  serial device (`composite device`) to the computer over a single USB cable.
+  This allows for Audio I/O and CAT control over a single USB cable which is
+  very convenient.
+
+  By including and maintaining this example in TinyUSB repository, we enable
+  the amateur radio community to build (`homebrew`) radios with similar
+  functionality as the (expensive) commercial rigs.
+
+  This PR is important in bridging this specific gap between the commercial
+  rigs and homebrew equipment.
+
+- https://digirig.net/digirig-mobile-rev-1-9/ is a digital interface for
+  interfacing radios (that lack an inbuilt digital interface) with computers.
+  Digirig Mobile works brilliantly (is OSS!) and is a big improvement over
+  traditional digital interfaces (like the SignaLink USB Interface). By using a
+  Raspberry Pi Pico powered CDC + UAC2 composite device, we can simplify the
+  Digirig Mobile schematic, drastically reduce the manufacturing cost, and
+  (again) enable the homebrewers community to homebrew a modern digital interface
+  with ease themselves.
+
+
+#### Build Steps
+
+```
+cd examples/device/cdc_uac2
+
+export PICO_SDK_PATH=$HOME/pico-sdk
+
+cmake -DFAMILY=rp2040 pico .
+
+cmake -DFAMILY=rp2040 -DCMAKE_BUILD_TYPE=Debug # use this for debugging
+
+make BOARD=raspberry_pi_pico all
+```
+
+
+#### Development Notes
+
+Please try to keep this code synchronized with the `uac2_headset` example
+included in this repository.
diff --git a/examples/device/cdc_uac2/src/cdc_app.c b/examples/device/cdc_uac2/src/cdc_app.c
new file mode 100644
index 000000000..2166c1d6b
--- /dev/null
+++ b/examples/device/cdc_uac2/src/cdc_app.c
@@ -0,0 +1,72 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ * Copyright (c) 2022 Angel Molina ([email protected])
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "bsp/board_api.h"
+#include "tusb.h"
+#include "common.h"
+
+// Invoked when cdc when line state changed e.g connected/disconnected
+void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts)
+{
+  (void) itf;
+  (void) rts;
+
+  if (dtr)
+  {
+    // Terminal connected
+  }
+  else
+  {
+    // Terminal disconnected
+  }
+}
+
+// Invoked when CDC interface received data from host
+void tud_cdc_rx_cb(uint8_t itf)
+{
+  uint8_t buf[64];
+  uint32_t count;
+
+  // connected() check for DTR bit
+  // Most but not all terminal client set this when making connection
+  if (tud_cdc_connected())
+  {
+    if (tud_cdc_available()) // data is available
+    {
+      count = tud_cdc_n_read(itf, buf, sizeof(buf));
+      (void) count;
+
+      tud_cdc_n_write(itf, buf, count);
+      tud_cdc_n_write_flush(itf);
+      // dummy code to check that cdc serial is responding
+      board_led_write(0);
+      board_delay(50);
+      board_led_write(1);
+      board_delay(50);
+      board_led_write(0);
+    }
+  }
+}
diff --git a/examples/device/cdc_uac2/src/common.h b/examples/device/cdc_uac2/src/common.h
new file mode 100644
index 000000000..f281024c7
--- /dev/null
+++ b/examples/device/cdc_uac2/src/common.h
@@ -0,0 +1,34 @@
+#ifndef __COMMON_H__
+#define __COMMON_H__
+
+/* Blink pattern
+ * - 25 ms   : streaming data
+ * - 250 ms  : device not mounted
+ * - 1000 ms : device mounted
+ * - 2500 ms : device is suspended
+ */
+enum
+{
+  BLINK_STREAMING = 25,
+  BLINK_NOT_MOUNTED = 250,
+  BLINK_MOUNTED = 1000,
+  BLINK_SUSPENDED = 2500,
+};
+
+enum
+{
+  VOLUME_CTRL_0_DB = 0,
+  VOLUME_CTRL_10_DB = 2560,
+  VOLUME_CTRL_20_DB = 5120,
+  VOLUME_CTRL_30_DB = 7680,
+  VOLUME_CTRL_40_DB = 10240,
+  VOLUME_CTRL_50_DB = 12800,
+  VOLUME_CTRL_60_DB = 15360,
+  VOLUME_CTRL_70_DB = 17920,
+  VOLUME_CTRL_80_DB = 20480,
+  VOLUME_CTRL_90_DB = 23040,
+  VOLUME_CTRL_100_DB = 25600,
+  VOLUME_CTRL_SILENCE = 0x8000,
+};
+
+#endif
diff --git a/examples/device/cdc_uac2/src/main.c b/examples/device/cdc_uac2/src/main.c
new file mode 100644
index 000000000..25b2cd9a5
--- /dev/null
+++ b/examples/device/cdc_uac2/src/main.c
@@ -0,0 +1,99 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Jerzy Kasenberg
+ * Copyright (c) 2022 Angel Molina <[email protected]>
+ * Copyright (c) 2023 Dhiru Kholia <[email protected]>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "bsp/board_api.h"
+#include "tusb.h"
+#include "common.h"
+
+extern uint32_t blink_interval_ms;
+
+#if (CFG_TUSB_MCU == OPT_MCU_RP2040)
+#include "pico/stdlib.h"
+#endif
+
+void led_blinking_task(void);
+
+/*------------- MAIN -------------*/
+int main(void)
+{
+  board_init();
+
+  // init device stack on configured roothub port
+  tud_init(BOARD_TUD_RHPORT);
+
+#if (CFG_TUSB_MCU == OPT_MCU_RP2040)
+  stdio_init_all();
+#endif
+
+  TU_LOG1("CDC UAC2 example running\r\n");
+
+  while (1)
+  {
+    tud_task(); // TinyUSB device task
+    led_blinking_task();
+
+#if (CFG_TUSB_MCU == OPT_MCU_RP2040)
+    // printf("Hello, world!\r\n");
+#endif
+  }
+
+  return 0;
+}
+
+//--------------------------------------------------------------------+
+// Device callbacks
+//--------------------------------------------------------------------+
+
+// Invoked when device is mounted
+void tud_mount_cb(void)
+{
+  blink_interval_ms = BLINK_MOUNTED;
+}
+
+// Invoked when device is unmounted
+void tud_umount_cb(void)
+{
+  blink_interval_ms = BLINK_NOT_MOUNTED;
+}
+
+// Invoked when usb bus is suspended
+// remote_wakeup_en : if host allow us  to perform remote wakeup
+// Within 7ms, device must draw an average of current less than 2.5 mA from bus
+void tud_suspend_cb(bool remote_wakeup_en)
+{
+  (void)remote_wakeup_en;
+  blink_interval_ms = BLINK_SUSPENDED;
+}
+
+// Invoked when usb bus is resumed
+void tud_resume_cb(void)
+{
+  blink_interval_ms = BLINK_MOUNTED;
+}
diff --git a/examples/device/cdc_uac2/src/tusb_config.h b/examples/device/cdc_uac2/src/tusb_config.h
new file mode 100644
index 000000000..93489cf62
--- /dev/null
+++ b/examples/device/cdc_uac2/src/tusb_config.h
@@ -0,0 +1,174 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Ha Thach (tinyusb.org)
+ * Copyright (c) 2020 Jerzy Kasenberg
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _TUSB_CONFIG_H_
+#define _TUSB_CONFIG_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "usb_descriptors.h"
+
+//--------------------------------------------------------------------+
+// Board Specific Configuration
+//--------------------------------------------------------------------+
+
+// RHPort number used for device can be defined by board.mk, default to port 0
+#ifndef BOARD_TUD_RHPORT
+#define BOARD_TUD_RHPORT      0
+#endif
+
+// RHPort max operational speed can defined by board.mk
+#ifndef BOARD_TUD_MAX_SPEED
+#define BOARD_TUD_MAX_SPEED   OPT_MODE_DEFAULT_SPEED
+#endif
+
+//--------------------------------------------------------------------
+// Common Configuration
+//--------------------------------------------------------------------
+
+// defined by compiler flags for flexibility
+#ifndef CFG_TUSB_MCU
+#error CFG_TUSB_MCU must be defined
+#endif
+
+#ifndef CFG_TUSB_OS
+#define CFG_TUSB_OS           OPT_OS_NONE
+#endif
+
+#ifndef CFG_TUSB_DEBUG
+#define CFG_TUSB_DEBUG        0
+#endif
+
+// Enable Device stack
+#define CFG_TUD_ENABLED       1
+
+// Default is max speed that hardware controller could support with on-chip PHY
+#define CFG_TUD_MAX_SPEED     BOARD_TUD_MAX_SPEED
+
+/* USB DMA on some MCUs can only access a specific SRAM region with restriction on alignment.
+ * Tinyusb use follows macros to declare transferring memory so that they can be put
+ * into those specific section.
+ * e.g
+ * - CFG_TUSB_MEM SECTION : __attribute__ (( section(".usb_ram") ))
+ * - CFG_TUSB_MEM_ALIGN   : __attribute__ ((aligned(4)))
+ */
+#ifndef CFG_TUSB_MEM_SECTION
+#define CFG_TUSB_MEM_SECTION
+#endif
+
+#ifndef CFG_TUSB_MEM_ALIGN
+#define CFG_TUSB_MEM_ALIGN        __attribute__ ((aligned(4)))
+#endif
+
+//--------------------------------------------------------------------
+// DEVICE CONFIGURATION
+//--------------------------------------------------------------------
+
+#ifndef CFG_TUD_ENDPOINT0_SIZE
+#define CFG_TUD_ENDPOINT0_SIZE    64
+#endif
+
+//------------- CLASS -------------//
+#define CFG_TUD_CDC               1
+#define CFG_TUD_MSC               0
+#define CFG_TUD_HID               0
+#define CFG_TUD_MIDI              0
+#define CFG_TUD_AUDIO             1
+#define CFG_TUD_VENDOR            0
+
+//--------------------------------------------------------------------
+// AUDIO CLASS DRIVER CONFIGURATION
+//--------------------------------------------------------------------
+
+#define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                                TUD_AUDIO_HEADSET_STEREO_DESC_LEN
+
+// How many formats are used, need to adjust USB descriptor if changed
+#define CFG_TUD_AUDIO_FUNC_1_N_FORMATS                               2
+
+// Audio format type I specifications
+#if defined(__RX__)
+#define CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE                         48000     // 16bit/48kHz is the best quality for Renesas RX
+#else
+#define CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE                         96000     // 24bit/96kHz is the best quality for full-speed, high-speed is needed beyond this
+#endif
+#define CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX                           1
+#define CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX                           1         // Changed
+
+// 16bit in 16bit slots
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX          2
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_TX                  16
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX          2
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX                  16
+
+#if defined(__RX__)
+// 8bit in 8bit slots
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX          1
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_TX                  8
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX          1
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_RX                  8
+#else
+// 24bit in 32bit slots
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX          4
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_TX                  24
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX          4
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_RX                  24
+#endif
+
+// EP and buffer size - for isochronous EP´s, the buffer and EP size are equal (different sizes would not make sense)
+#define CFG_TUD_AUDIO_ENABLE_EP_IN                1
+
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN    TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX)
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_IN    TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX)
+
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ      TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN)
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX         TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_IN) // Maximum EP IN size for all AS alternate settings used
+
+// EP and buffer size - for isochronous EP´s, the buffer and EP size are equal (different sizes would not make sense)
+#define CFG_TUD_AUDIO_ENABLE_EP_OUT               1
+
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT   TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX)
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_OUT   TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX)
+
+#define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ     TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT)
+#define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX        TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT) // Maximum EP IN size for all AS alternate settings used
+
+// Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
+#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT 	          2
+
+// Size of control request buffer
+#define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ          64
+
+// CDC FIFO size of TX and RX
+#define CFG_TUD_CDC_RX_BUFSIZE                    64
+#define CFG_TUD_CDC_TX_BUFSIZE                    64
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _TUSB_CONFIG_H_ */
diff --git a/examples/device/cdc_uac2/src/uac2_app.c b/examples/device/cdc_uac2/src/uac2_app.c
new file mode 100644
index 000000000..98659ea68
--- /dev/null
+++ b/examples/device/cdc_uac2/src/uac2_app.c
@@ -0,0 +1,316 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Jerzy Kasenberg
+ * Copyright (c) 2022 Angel Molina ([email protected])
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "bsp/board_api.h"
+#include "tusb.h"
+#include "usb_descriptors.h"
+#include "common.h"
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF PROTOTYPES
+//--------------------------------------------------------------------+
+
+// List of supported sample rates
+const uint32_t sample_rates[] = {44100, 48000};
+uint32_t current_sample_rate  = 44100;
+
+#define N_SAMPLE_RATES  TU_ARRAY_SIZE(sample_rates)
+
+uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
+
+// Audio controls
+// Current states
+int8_t mute[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX + 1];       // +1 for master channel 0
+int16_t volume[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX + 1];    // +1 for master channel 0
+
+// Buffer for microphone data
+int32_t mic_buf[CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ / 4];
+// Buffer for speaker data
+int32_t spk_buf[CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ / 4];
+// Speaker data size received in the last frame
+int spk_data_size;
+// Resolution per format
+const uint8_t resolutions_per_format[CFG_TUD_AUDIO_FUNC_1_N_FORMATS] = {CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX};
+// Current resolution, update on format change
+uint8_t current_resolution;
+
+// Helper for clock get requests
+static bool tud_audio_clock_get_request(uint8_t rhport, audio_control_request_t const *request)
+{
+  TU_ASSERT(request->bEntityID == UAC2_ENTITY_CLOCK);
+
+  if (request->bControlSelector == AUDIO_CS_CTRL_SAM_FREQ)
+  {
+    if (request->bRequest == AUDIO_CS_REQ_CUR)
+    {
+      TU_LOG1("Clock get current freq %lu\r\n", current_sample_rate);
+
+      audio_control_cur_4_t curf = { (int32_t) tu_htole32(current_sample_rate) };
+      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &curf, sizeof(curf));
+    }
+    else if (request->bRequest == AUDIO_CS_REQ_RANGE)
+    {
+      audio_control_range_4_n_t(N_SAMPLE_RATES) rangef =
+      {
+        .wNumSubRanges = tu_htole16(N_SAMPLE_RATES)
+      };
+      TU_LOG1("Clock get %d freq ranges\r\n", N_SAMPLE_RATES);
+      for(uint8_t i = 0; i < N_SAMPLE_RATES; i++)
+      {
+        rangef.subrange[i].bMin = (int32_t) sample_rates[i];
+        rangef.subrange[i].bMax = (int32_t) sample_rates[i];
+        rangef.subrange[i].bRes = 0;
+        TU_LOG1("Range %d (%d, %d, %d)\r\n", i, (int)rangef.subrange[i].bMin, (int)rangef.subrange[i].bMax, (int)rangef.subrange[i].bRes);
+      }
+
+      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &rangef, sizeof(rangef));
+    }
+  }
+  else if (request->bControlSelector == AUDIO_CS_CTRL_CLK_VALID &&
+           request->bRequest == AUDIO_CS_REQ_CUR)
+  {
+    audio_control_cur_1_t cur_valid = { .bCur = 1 };
+    TU_LOG1("Clock get is valid %u\r\n", cur_valid.bCur);
+    return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &cur_valid, sizeof(cur_valid));
+  }
+  TU_LOG1("Clock get request not supported, entity = %u, selector = %u, request = %u\r\n",
+          request->bEntityID, request->bControlSelector, request->bRequest);
+  return false;
+}
+
+// Helper for clock set requests
+static bool tud_audio_clock_set_request(uint8_t rhport, audio_control_request_t const *request, uint8_t const *buf)
+{
+  (void)rhport;
+
+  TU_ASSERT(request->bEntityID == UAC2_ENTITY_CLOCK);
+  TU_VERIFY(request->bRequest == AUDIO_CS_REQ_CUR);
+
+  if (request->bControlSelector == AUDIO_CS_CTRL_SAM_FREQ)
+  {
+    TU_VERIFY(request->wLength == sizeof(audio_control_cur_4_t));
+
+    current_sample_rate = (uint32_t) ((audio_control_cur_4_t const *)buf)->bCur;
+
+    TU_LOG1("Clock set current freq: %ld\r\n", current_sample_rate);
+
+    return true;
+  }
+  else
+  {
+    TU_LOG1("Clock set request not supported, entity = %u, selector = %u, request = %u\r\n",
+            request->bEntityID, request->bControlSelector, request->bRequest);
+    return false;
+  }
+}
+
+// Helper for feature unit get requests
+static bool tud_audio_feature_unit_get_request(uint8_t rhport, audio_control_request_t const *request)
+{
+  TU_ASSERT(request->bEntityID == UAC2_ENTITY_SPK_FEATURE_UNIT);
+
+  if (request->bControlSelector == AUDIO_FU_CTRL_MUTE && request->bRequest == AUDIO_CS_REQ_CUR)
+  {
+    audio_control_cur_1_t mute1 = { .bCur = mute[request->bChannelNumber] };
+    TU_LOG1("Get channel %u mute %d\r\n", request->bChannelNumber, mute1.bCur);
+    return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &mute1, sizeof(mute1));
+  }
+  else if (UAC2_ENTITY_SPK_FEATURE_UNIT && request->bControlSelector == AUDIO_FU_CTRL_VOLUME)
+  {
+    if (request->bRequest == AUDIO_CS_REQ_RANGE)
+    {
+      audio_control_range_2_n_t(1) range_vol = {
+        .wNumSubRanges = tu_htole16(1),
+        .subrange[0] = { .bMin = tu_htole16(-VOLUME_CTRL_50_DB), tu_htole16(VOLUME_CTRL_0_DB), tu_htole16(256) }
+      };
+      TU_LOG1("Get channel %u volume range (%d, %d, %u) dB\r\n", request->bChannelNumber,
+              range_vol.subrange[0].bMin / 256, range_vol.subrange[0].bMax / 256, range_vol.subrange[0].bRes / 256);
+      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &range_vol, sizeof(range_vol));
+    }
+    else if (request->bRequest == AUDIO_CS_REQ_CUR)
+    {
+      audio_control_cur_2_t cur_vol = { .bCur = tu_htole16(volume[request->bChannelNumber]) };
+      TU_LOG1("Get channel %u volume %d dB\r\n", request->bChannelNumber, cur_vol.bCur / 256);
+      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &cur_vol, sizeof(cur_vol));
+    }
+  }
+  TU_LOG1("Feature unit get request not supported, entity = %u, selector = %u, request = %u\r\n",
+          request->bEntityID, request->bControlSelector, request->bRequest);
+
+  return false;
+}
+
+// Helper for feature unit set requests
+static bool tud_audio_feature_unit_set_request(uint8_t rhport, audio_control_request_t const *request, uint8_t const *buf)
+{
+  (void)rhport;
+
+  TU_ASSERT(request->bEntityID == UAC2_ENTITY_SPK_FEATURE_UNIT);
+  TU_VERIFY(request->bRequest == AUDIO_CS_REQ_CUR);
+
+  if (request->bControlSelector == AUDIO_FU_CTRL_MUTE)
+  {
+    TU_VERIFY(request->wLength == sizeof(audio_control_cur_1_t));
+
+    mute[request->bChannelNumber] = ((audio_control_cur_1_t const *)buf)->bCur;
+
+    TU_LOG1("Set channel %d Mute: %d\r\n", request->bChannelNumber, mute[request->bChannelNumber]);
+
+    return true;
+  }
+  else if (request->bControlSelector == AUDIO_FU_CTRL_VOLUME)
+  {
+    TU_VERIFY(request->wLength == sizeof(audio_control_cur_2_t));
+
+    volume[request->bChannelNumber] = ((audio_control_cur_2_t const *)buf)->bCur;
+
+    TU_LOG1("Set channel %d volume: %d dB\r\n", request->bChannelNumber, volume[request->bChannelNumber] / 256);
+
+    return true;
+  }
+  else
+  {
+    TU_LOG1("Feature unit set request not supported, entity = %u, selector = %u, request = %u\r\n",
+            request->bEntityID, request->bControlSelector, request->bRequest);
+    return false;
+  }
+}
+
+//--------------------------------------------------------------------+
+// Application Callback API Implementations
+//--------------------------------------------------------------------+
+
+// Invoked when audio class specific get request received for an entity
+bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const *p_request)
+{
+  audio_control_request_t const *request = (audio_control_request_t const *)p_request;
+
+  if (request->bEntityID == UAC2_ENTITY_CLOCK)
+    return tud_audio_clock_get_request(rhport, request);
+  if (request->bEntityID == UAC2_ENTITY_SPK_FEATURE_UNIT)
+    return tud_audio_feature_unit_get_request(rhport, request);
+  else
+  {
+    TU_LOG1("Get request not handled, entity = %d, selector = %d, request = %d\r\n",
+            request->bEntityID, request->bControlSelector, request->bRequest);
+  }
+  return false;
+}
+
+// Invoked when audio class specific set request received for an entity
+bool tud_audio_set_req_entity_cb(uint8_t rhport, tusb_control_request_t const *p_request, uint8_t *buf)
+{
+  audio_control_request_t const *request = (audio_control_request_t const *)p_request;
+
+  if (request->bEntityID == UAC2_ENTITY_SPK_FEATURE_UNIT)
+    return tud_audio_feature_unit_set_request(rhport, request, buf);
+  if (request->bEntityID == UAC2_ENTITY_CLOCK)
+    return tud_audio_clock_set_request(rhport, request, buf);
+  TU_LOG1("Set request not handled, entity = %d, selector = %d, request = %d\r\n",
+          request->bEntityID, request->bControlSelector, request->bRequest);
+
+  return false;
+}
+
+bool tud_audio_set_itf_close_EP_cb(uint8_t rhport, tusb_control_request_t const * p_request)
+{
+  (void)rhport;
+
+  uint8_t const itf = tu_u16_low(tu_le16toh(p_request->wIndex));
+  uint8_t const alt = tu_u16_low(tu_le16toh(p_request->wValue));
+
+  if (ITF_NUM_AUDIO_STREAMING_SPK == itf && alt == 0) {
+    // Audio streaming stop
+    blink_interval_ms = BLINK_MOUNTED;
+  }
+
+  return true;
+}
+
+bool tud_audio_set_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request)
+{
+  (void)rhport;
+  uint8_t const itf = tu_u16_low(tu_le16toh(p_request->wIndex));
+  uint8_t const alt = tu_u16_low(tu_le16toh(p_request->wValue));
+
+  TU_LOG2("Set interface %d alt %d\r\n", itf, alt);
+  if (ITF_NUM_AUDIO_STREAMING_SPK == itf && alt != 0) {
+    // Audio streaming start
+    blink_interval_ms = BLINK_STREAMING;
+  }
+
+  // Clear buffer when streaming format is changed
+  spk_data_size = 0;
+  if(alt != 0)
+  {
+    current_resolution = resolutions_per_format[alt-1];
+  }
+
+  return true;
+}
+
+bool tud_audio_rx_done_pre_read_cb(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out, uint8_t cur_alt_setting)
+{
+  (void)rhport;
+  (void)func_id;
+  (void)ep_out;
+  (void)cur_alt_setting;
+
+  spk_data_size = tud_audio_read(spk_buf, n_bytes_received);
+  tud_audio_write(spk_buf, n_bytes_received);
+
+  return true;
+}
+
+bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t itf, uint8_t ep_in, uint8_t cur_alt_setting)
+{
+  (void)rhport;
+  (void)itf;
+  (void)ep_in;
+  (void)cur_alt_setting;
+
+  // This callback could be used to fill microphone data separately
+  return true;
+}
+
+//--------------------------------------------------------------------+
+// BLINKING TASK
+//--------------------------------------------------------------------+
+void led_blinking_task(void)
+{
+  static uint32_t start_ms = 0;
+  static bool led_state = false;
+
+  // Blink every interval ms
+  if (board_millis() - start_ms < blink_interval_ms) return;
+  start_ms += blink_interval_ms;
+
+  board_led_write(led_state);
+  led_state = 1 - led_state;
+}
diff --git a/examples/device/cdc_uac2/src/usb_descriptors.c b/examples/device/cdc_uac2/src/usb_descriptors.c
new file mode 100644
index 000000000..72a695622
--- /dev/null
+++ b/examples/device/cdc_uac2/src/usb_descriptors.c
@@ -0,0 +1,216 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Ha Thach (tinyusb.org)
+ * Copyright (c) 2020 Jerzy Kasenberg
+ * Copyright (c) 2022 Angel Molina ([email protected])
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "bsp/board_api.h"
+#include "tusb.h"
+#include "usb_descriptors.h"
+
+/* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
+ * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
+ *
+ * Auto ProductID layout's Bitmap:
+ *   [MSB]     AUDIO | MIDI | HID | MSC | CDC          [LSB]
+ */
+#define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
+#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
+    _PID_MAP(MIDI, 3) | _PID_MAP(AUDIO, 4) | _PID_MAP(VENDOR, 5) )
+
+//--------------------------------------------------------------------+
+// Device Descriptors
+//--------------------------------------------------------------------+
+tusb_desc_device_t const desc_device =
+{
+    .bLength            = sizeof(tusb_desc_device_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bcdUSB             = 0x0200,
+
+    // Use Interface Association Descriptor (IAD)
+    // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+
+    .idVendor           = 0xCafe,
+    .idProduct          = USB_PID,
+    .bcdDevice          = 0x0100,
+
+    .iManufacturer      = 0x01,
+    .iProduct           = 0x02,
+    .iSerialNumber      = 0x03,
+
+    .bNumConfigurations = 0x01
+};
+
+// Invoked when received GET DEVICE DESCRIPTOR
+// Application return pointer to descriptor
+uint8_t const * tud_descriptor_device_cb(void)
+{
+  return (uint8_t const *)&desc_device;
+}
+
+//--------------------------------------------------------------------+
+// Configuration Descriptor
+//--------------------------------------------------------------------+
+#define CONFIG_TOTAL_LEN    	(TUD_CONFIG_DESC_LEN + CFG_TUD_AUDIO * TUD_AUDIO_HEADSET_STEREO_DESC_LEN + CFG_TUD_CDC * TUD_CDC_DESC_LEN)
+
+#if CFG_TUSB_MCU == OPT_MCU_LPC175X_6X || CFG_TUSB_MCU == OPT_MCU_LPC177X_8X || CFG_TUSB_MCU == OPT_MCU_LPC40XX
+  // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
+  // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In etc ...
+  #define EPNUM_AUDIO_IN    0x03
+  #define EPNUM_AUDIO_OUT   0x03
+
+  #define EPNUM_CDC_NOTIF   0x84
+  #define EPNUM_CDC_OUT     0x05
+  #define EPNUM_CDC_IN      0x85
+
+#elif CFG_TUSB_MCU == OPT_MCU_NRF5X
+  // ISO endpoints for NRF5x are fixed to 0x08 (0x88)
+  #define EPNUM_AUDIO_IN    0x08
+  #define EPNUM_AUDIO_OUT   0x08
+
+  #define EPNUM_CDC_NOTIF   0x81
+  #define EPNUM_CDC_OUT     0x02
+  #define EPNUM_CDC_IN      0x82
+
+#elif CFG_TUSB_MCU == OPT_MCU_SAMG  || CFG_TUSB_MCU ==  OPT_MCU_SAMX7X
+  // SAMG & SAME70 don't support a same endpoint number with different direction IN and OUT
+  //    e.g EP1 OUT & EP1 IN cannot exist together
+  #define EPNUM_AUDIO_IN    0x01
+  #define EPNUM_AUDIO_OUT   0x02
+
+  #define EPNUM_CDC_NOTIF   0x83
+  #define EPNUM_CDC_OUT     0x04
+  #define EPNUM_CDC_IN      0x85
+
+#elif CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X
+  // FT9XX doesn't support a same endpoint number with different direction IN and OUT
+  //    e.g EP1 OUT & EP1 IN cannot exist together
+  #define EPNUM_AUDIO_IN    0x01
+  #define EPNUM_AUDIO_OUT   0x02
+
+  #define EPNUM_CDC_NOTIF   0x83
+  #define EPNUM_CDC_OUT     0x04
+  #define EPNUM_CDC_IN      0x85
+
+#else
+  #define EPNUM_AUDIO_IN    0x01
+  #define EPNUM_AUDIO_OUT   0x01
+
+  #define EPNUM_CDC_NOTIF   0x83
+  #define EPNUM_CDC_OUT     0x04
+  #define EPNUM_CDC_IN      0x84
+#endif
+
+uint8_t const desc_configuration[] =
+{
+    // Config number, interface count, string index, total length, attribute, power in mA
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
+
+    // Interface number, string index, EP Out & EP In address, EP size
+    TUD_AUDIO_HEADSET_STEREO_DESCRIPTOR(2, EPNUM_AUDIO_OUT, EPNUM_AUDIO_IN | 0x80),
+
+    // CDC: Interface number, string index, EP notification address and size, EP data address (out, in) and size.
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 6, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64)
+};
+
+// Invoked when received GET CONFIGURATION DESCRIPTOR
+// Application return pointer to descriptor
+// Descriptor contents must exist long enough for transfer to complete
+uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
+{
+  (void)index; // for multiple configurations
+  return desc_configuration;
+}
+
+//--------------------------------------------------------------------+
+// String Descriptors
+//--------------------------------------------------------------------+
+
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
+// array of pointer to string descriptors
+char const *string_desc_arr[] =
+{
+  (const char[]) { 0x09, 0x04 },  // 0: is supported language is English (0x0409)
+  "TinyUSB",                      // 1: Manufacturer
+  "TinyUSB headset",              // 2: Product
+  NULL,                           // 3: Serials will use unique ID if possible
+  "TinyUSB Speakers",             // 4: Audio Interface
+  "TinyUSB Microphone",           // 5: Audio Interface
+  "TinyUSB CDC",                  // 6: Audio Interface
+};
+
+static uint16_t _desc_str[32 + 1];
+
+// Invoked when received GET STRING DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
+  (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
+
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
+
+      const char *str = string_desc_arr[index];
+
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
+
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
+  }
+
+  // first byte is length (including header), second byte is string type
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
+
+  return _desc_str;
+}
diff --git a/examples/device/cdc_uac2/src/usb_descriptors.h b/examples/device/cdc_uac2/src/usb_descriptors.h
new file mode 100644
index 000000000..736feeefe
--- /dev/null
+++ b/examples/device/cdc_uac2/src/usb_descriptors.h
@@ -0,0 +1,158 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Jerzy Kasenbreg
+ * Copyright (c) 2022 Angel Molina ([email protected])
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _USB_DESCRIPTORS_H_
+#define _USB_DESCRIPTORS_H_
+
+// #include "tusb.h"
+
+// Unit numbers are arbitrary selected
+#define UAC2_ENTITY_CLOCK               0x04
+// Speaker path
+#define UAC2_ENTITY_SPK_INPUT_TERMINAL  0x01
+#define UAC2_ENTITY_SPK_FEATURE_UNIT    0x02
+#define UAC2_ENTITY_SPK_OUTPUT_TERMINAL 0x03
+// Microphone path
+#define UAC2_ENTITY_MIC_INPUT_TERMINAL  0x11
+#define UAC2_ENTITY_MIC_OUTPUT_TERMINAL 0x13
+
+enum
+{
+  ITF_NUM_AUDIO_CONTROL = 0,
+  ITF_NUM_AUDIO_STREAMING_SPK,
+  ITF_NUM_AUDIO_STREAMING_MIC,
+  ITF_NUM_CDC,
+  ITF_NUM_CDC_DATA,
+  ITF_NUM_TOTAL
+};
+
+#define TUD_AUDIO_HEADSET_STEREO_DESC_LEN (TUD_AUDIO_DESC_IAD_LEN\
+    + TUD_AUDIO_DESC_STD_AC_LEN\
+    + TUD_AUDIO_DESC_CS_AC_LEN\
+    + TUD_AUDIO_DESC_CLK_SRC_LEN\
+    + TUD_AUDIO_DESC_INPUT_TERM_LEN\
+    + TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL_LEN\
+    + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
+    + TUD_AUDIO_DESC_INPUT_TERM_LEN\
+    + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
+    /* Interface 1, Alternate 0 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    /* Interface 1, Alternate 0 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
+    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
+    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
+    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
+    /* Interface 1, Alternate 2 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
+    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
+    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
+    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
+    /* Interface 2, Alternate 0 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    /* Interface 2, Alternate 1 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
+    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
+    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
+    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
+    /* Interface 2, Alternate 2 */\
+    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
+    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
+    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
+    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
+    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN)
+
+#define TUD_AUDIO_HEADSET_STEREO_DESCRIPTOR(_stridx, _epout, _epin) \
+    /* Standard Interface Association Descriptor (IAD) */\
+    TUD_AUDIO_DESC_IAD(/*_firstitfs*/ ITF_NUM_AUDIO_CONTROL, /*_nitfs*/ 3, /*_stridx*/ 0x00),\
+    /* Standard AC Interface Descriptor(4.7.1) */\
+    TUD_AUDIO_DESC_STD_AC(/*_itfnum*/ ITF_NUM_AUDIO_CONTROL, /*_nEPs*/ 0x00, /*_stridx*/ _stridx),\
+    /* Class-Specific AC Interface Header Descriptor(4.7.2) */\
+    TUD_AUDIO_DESC_CS_AC(/*_bcdADC*/ 0x0200, /*_category*/ AUDIO_FUNC_HEADSET, /*_totallen*/ TUD_AUDIO_DESC_CLK_SRC_LEN+TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL_LEN+TUD_AUDIO_DESC_INPUT_TERM_LEN+TUD_AUDIO_DESC_OUTPUT_TERM_LEN+TUD_AUDIO_DESC_INPUT_TERM_LEN+TUD_AUDIO_DESC_OUTPUT_TERM_LEN, /*_ctrl*/ AUDIO_CS_AS_INTERFACE_CTRL_LATENCY_POS),\
+    /* Clock Source Descriptor(4.7.2.1) */\
+    TUD_AUDIO_DESC_CLK_SRC(/*_clkid*/ UAC2_ENTITY_CLOCK, /*_attr*/ 3, /*_ctrl*/ 7, /*_assocTerm*/ 0x00,  /*_stridx*/ 0x00),    \
+    /* Input Terminal Descriptor(4.7.2.4) */\
+    TUD_AUDIO_DESC_INPUT_TERM(/*_termid*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_USB_STREAMING, /*_assocTerm*/ 0x00, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_nchannelslogical*/ 0x02, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_idxchannelnames*/ 0x00, /*_ctrl*/ 0 * (AUDIO_CTRL_R << AUDIO_IN_TERM_CTRL_CONNECTOR_POS), /*_stridx*/ 0x00),\
+    /* Feature Unit Descriptor(4.7.2.8) */\
+    TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL(/*_unitid*/ UAC2_ENTITY_SPK_FEATURE_UNIT, /*_srcid*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_ctrlch0master*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_ctrlch1*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_ctrlch2*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_stridx*/ 0x00),\
+    /* Output Terminal Descriptor(4.7.2.5) */\
+    TUD_AUDIO_DESC_OUTPUT_TERM(/*_termid*/ UAC2_ENTITY_SPK_OUTPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_OUT_HEADPHONES, /*_assocTerm*/ 0x00, /*_srcid*/ UAC2_ENTITY_SPK_FEATURE_UNIT, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_ctrl*/ 0x0000, /*_stridx*/ 0x00),\
+    /* Input Terminal Descriptor(4.7.2.4) */\
+    TUD_AUDIO_DESC_INPUT_TERM(/*_termid*/ UAC2_ENTITY_MIC_INPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_IN_GENERIC_MIC, /*_assocTerm*/ 0x00, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_nchannelslogical*/ 0x01, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_idxchannelnames*/ 0x00, /*_ctrl*/ 0 * (AUDIO_CTRL_R << AUDIO_IN_TERM_CTRL_CONNECTOR_POS), /*_stridx*/ 0x00),\
+    /* Output Terminal Descriptor(4.7.2.5) */\
+    TUD_AUDIO_DESC_OUTPUT_TERM(/*_termid*/ UAC2_ENTITY_MIC_OUTPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_USB_STREAMING, /*_assocTerm*/ 0x00, /*_srcid*/ UAC2_ENTITY_MIC_INPUT_TERMINAL, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_ctrl*/ 0x0000, /*_stridx*/ 0x00),\
+    /* Standard AS Interface Descriptor(4.9.1) */\
+    /* Interface 1, Alternate 0 - default alternate setting with 0 bandwidth */\
+    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_SPK), /*_altset*/ 0x00, /*_nEPs*/ 0x00, /*_stridx*/ 0x05),\
+    /* Standard AS Interface Descriptor(4.9.1) */\
+    /* Interface 1, Alternate 1 - alternate interface for data streaming */\
+    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_SPK), /*_altset*/ 0x01, /*_nEPs*/ 0x01, /*_stridx*/ 0x05),\
+    /* Class-Specific AS Interface Descriptor(4.9.2) */\
+    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
+    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
+    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX),\
+    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ADAPTIVE | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
+    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
+    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC, /*_lockdelay*/ 0x0001),\
+    /* Interface 1, Alternate 2 - alternate interface for data streaming */\
+    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_SPK), /*_altset*/ 0x02, /*_nEPs*/ 0x01, /*_stridx*/ 0x05),\
+    /* Class-Specific AS Interface Descriptor(4.9.2) */\
+    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
+    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
+    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_RX),\
+    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ADAPTIVE | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
+    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
+    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC, /*_lockdelay*/ 0x0001),\
+    /* Standard AS Interface Descriptor(4.9.1) */\
+    /* Interface 2, Alternate 0 - default alternate setting with 0 bandwidth */\
+    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_MIC), /*_altset*/ 0x00, /*_nEPs*/ 0x00, /*_stridx*/ 0x04),\
+    /* Standard AS Interface Descriptor(4.9.1) */\
+    /* Interface 2, Alternate 1 - alternate interface for data streaming */\
+    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_MIC), /*_altset*/ 0x01, /*_nEPs*/ 0x01, /*_stridx*/ 0x04),\
+    /* Class-Specific AS Interface Descriptor(4.9.2) */\
+    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_MIC_OUTPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
+    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
+    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_TX),\
+    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX), /*_interval*/ 0x01),\
+    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
+    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000),\
+    /* Interface 2, Alternate 2 - alternate interface for data streaming */\
+    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_MIC), /*_altset*/ 0x02, /*_nEPs*/ 0x01, /*_stridx*/ 0x04),\
+    /* Class-Specific AS Interface Descriptor(4.9.2) */\
+    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_MIC_OUTPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
+    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
+    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_TX),\
+    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX), /*_interval*/ 0x01),\
+    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
+    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000)
+
+#endif
diff --git a/examples/device/dfu/CMakeLists.txt b/examples/device/dfu/CMakeLists.txt
index acaa54198..a01eb3456 100644
--- a/examples/device/dfu/CMakeLists.txt
+++ b/examples/device/dfu/CMakeLists.txt
@@ -1,14 +1,18 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
 
@@ -23,6 +27,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/dfu/Makefile b/examples/device/dfu/Makefile
index 69b633fea..52a24cdb0 100644
--- a/examples/device/dfu/Makefile
+++ b/examples/device/dfu/Makefile
@@ -1,12 +1,14 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
 	$(TOP)/hw \
 
 # Example source
-EXAMPLE_SOURCE += $(wildcard src/*.c)
+EXAMPLE_SOURCE = \
+	src/main.c \
+	src/usb_descriptors.c
+
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/dfu/skip.txt b/examples/device/dfu/skip.txt
index 9ac346bad..9dde06c30 100644
--- a/examples/device/dfu/skip.txt
+++ b/examples/device/dfu/skip.txt
@@ -1,2 +1,3 @@
 mcu:TM4C123
 mcu:BCM2835
+family:espressif
diff --git a/examples/device/dfu/src/main.c b/examples/device/dfu/src/main.c
index 6bb183819..81fc0a62c 100644
--- a/examples/device/dfu/src/main.c
+++ b/examples/device/dfu/src/main.c
@@ -42,7 +42,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 //--------------------------------------------------------------------+
@@ -77,13 +77,15 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
     led_blinking_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -114,7 +116,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
diff --git a/examples/device/dfu/src/usb_descriptors.c b/examples/device/dfu/src/usb_descriptors.c
index 51a0d09f5..fd469aaf2 100644
--- a/examples/device/dfu/src/usb_descriptors.c
+++ b/examples/device/dfu/src/usb_descriptors.c
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "class/dfu/dfu_device.h"
 
@@ -116,56 +117,65 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
   "FLASH",                       // 4: DFU Partition 1
   "EEPROM",                      // 5: DFU Partition 2
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
-
   size_t chr_count;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }
-  else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
+
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) {
-      chr_count = 31;
-    }
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t)((((uint16_t)TUSB_DESC_STRING) << 8 ) | (2u*chr_count + 2u));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/dfu_runtime/CMakeLists.txt b/examples/device/dfu_runtime/CMakeLists.txt
index abc4d91da..a01eb3456 100644
--- a/examples/device/dfu_runtime/CMakeLists.txt
+++ b/examples/device/dfu_runtime/CMakeLists.txt
@@ -1,14 +1,18 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
 
@@ -23,6 +27,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/dfu_runtime/Makefile b/examples/device/dfu_runtime/Makefile
index 69b633fea..1b4d398cf 100644
--- a/examples/device/dfu_runtime/Makefile
+++ b/examples/device/dfu_runtime/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/dfu_runtime/src/main.c b/examples/device/dfu_runtime/src/main.c
index 55b380353..170dde932 100644
--- a/examples/device/dfu_runtime/src/main.c
+++ b/examples/device/dfu_runtime/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -31,7 +31,7 @@
  *
  * $ dfu-util -e
  *
- * This will send DETTACH command to put device into bootloader. Since this example
+ * This will send DETACH command to put device into bootloader. Since this example
  * is minimal, it doesn't actually go into DFU mode but rather change the LED blinking
  * pattern to fast rate as indicator.
  */
@@ -40,7 +40,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 //--------------------------------------------------------------------+
@@ -72,13 +72,15 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
     led_blinking_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -109,7 +111,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 // Invoked on DFU_DETACH request to reboot to the bootloader
diff --git a/examples/device/dfu_runtime/src/usb_descriptors.c b/examples/device/dfu_runtime/src/usb_descriptors.c
index 1b0a60551..7ac53d255 100644
--- a/examples/device/dfu_runtime/src/usb_descriptors.c
+++ b/examples/device/dfu_runtime/src/usb_descriptors.c
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "class/dfu/dfu_rt_device.h"
 
@@ -112,55 +113,64 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
   "TinyUSB DFU runtime",         // 4: DFU runtime
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
-
   size_t chr_count;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }
-  else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
+
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) {
-      chr_count = 31;
-    }
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/dynamic_configuration/CMakeLists.txt b/examples/device/dynamic_configuration/CMakeLists.txt
index fa6e83b7e..2b20d2234 100644
--- a/examples/device/dynamic_configuration/CMakeLists.txt
+++ b/examples/device/dynamic_configuration/CMakeLists.txt
@@ -1,14 +1,18 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
 
@@ -24,6 +28,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/dynamic_configuration/Makefile b/examples/device/dynamic_configuration/Makefile
index 69b633fea..1b4d398cf 100644
--- a/examples/device/dynamic_configuration/Makefile
+++ b/examples/device/dynamic_configuration/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/dynamic_configuration/skip.txt b/examples/device/dynamic_configuration/skip.txt
index d844feae8..833fd072c 100644
--- a/examples/device/dynamic_configuration/skip.txt
+++ b/examples/device/dynamic_configuration/skip.txt
@@ -1 +1,2 @@
-mcu:SAMD11
\ No newline at end of file
+mcu:SAMD11
+family:espressif
diff --git a/examples/device/dynamic_configuration/src/main.c b/examples/device/dynamic_configuration/src/main.c
index 33a603343..b6409c8e1 100644
--- a/examples/device/dynamic_configuration/src/main.c
+++ b/examples/device/dynamic_configuration/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 //--------------------------------------------------------------------+
@@ -59,6 +59,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
@@ -66,8 +70,6 @@ int main(void)
     cdc_task();
     midi_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -98,7 +100,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 
diff --git a/examples/device/dynamic_configuration/src/msc_disk.c b/examples/device/dynamic_configuration/src/msc_disk.c
index e8cb03fdd..10c3ac6fe 100644
--- a/examples/device/dynamic_configuration/src/msc_disk.c
+++ b/examples/device/dynamic_configuration/src/msc_disk.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,7 +23,7 @@
  *
  */
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #if CFG_TUD_MSC
diff --git a/examples/device/dynamic_configuration/src/usb_descriptors.c b/examples/device/dynamic_configuration/src/usb_descriptors.c
index 457f774d0..7f35b4b22 100644
--- a/examples/device/dynamic_configuration/src/usb_descriptors.c
+++ b/examples/device/dynamic_configuration/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,8 +23,8 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
-#include "bsp/board.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
  * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
@@ -145,6 +145,19 @@ enum
   #define EPNUM_1_MSC_OUT     0x01
   #define EPNUM_1_MSC_IN      0x82
 
+#elif CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X
+  // FT9XX doesn't support a same endpoint number with different direction IN and OUT
+  //    e.g EP1 OUT & EP1 IN cannot exist together
+  #define EPNUM_0_CDC_NOTIF   0x81
+  #define EPNUM_0_CDC_OUT     0x02
+  #define EPNUM_0_CDC_IN      0x83
+
+  #define EPNUM_0_MIDI_OUT    0x04
+  #define EPNUM_0_MIDI_IN     0x85
+
+  #define EPNUM_1_MSC_OUT     0x01
+  #define EPNUM_1_MSC_IN      0x82
+
 #else
   #define EPNUM_0_CDC_NOTIF   0x81
   #define EPNUM_0_CDC_OUT     0x02
@@ -170,7 +183,7 @@ uint8_t const desc_configuration_0[] =
 };
 
 
-uint8_t const desc_configuraiton_1[] =
+uint8_t const desc_configuration_1[] =
 {
   // Config number, interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(1, ITF_1_NUM_TOTAL, 0, CONFIG_1_TOTAL_LEN, 0x00, 100),
@@ -186,58 +199,70 @@ uint8_t const desc_configuraiton_1[] =
 uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 {
   (void) index; // for multiple configurations
-  return mode ? desc_configuraiton_1 : desc_configuration_0;
+  return mode ? desc_configuration_1 : desc_configuration_0;
 }
 
 //--------------------------------------------------------------------+
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/hid_boot_interface/CMakeLists.txt b/examples/device/hid_boot_interface/CMakeLists.txt
index abc4d91da..a01eb3456 100644
--- a/examples/device/hid_boot_interface/CMakeLists.txt
+++ b/examples/device/hid_boot_interface/CMakeLists.txt
@@ -1,14 +1,18 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
 
@@ -23,6 +27,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/hid_boot_interface/Makefile b/examples/device/hid_boot_interface/Makefile
index c6a9c5b21..52a24cdb0 100644
--- a/examples/device/hid_boot_interface/Makefile
+++ b/examples/device/hid_boot_interface/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
@@ -9,7 +8,7 @@ INC += \
 EXAMPLE_SOURCE = \
 	src/main.c \
 	src/usb_descriptors.c
-	
+
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/hid_boot_interface/src/main.c b/examples/device/hid_boot_interface/src/main.c
index 71afa3f46..7ad5c53c2 100644
--- a/examples/device/hid_boot_interface/src/main.c
+++ b/examples/device/hid_boot_interface/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -59,6 +59,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
@@ -98,7 +102,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
@@ -157,11 +161,11 @@ void hid_task(void)
       {
         uint8_t const report_id   = 0;
         uint8_t const button_mask = 0;
-        uint8_t const veritical   = 0;
+        uint8_t const vertical    = 0;
         uint8_t const horizontal  = 0;
         int8_t  const delta       = 5;
 
-        tud_hid_n_mouse_report(ITF_NUM_MOUSE, report_id, button_mask, delta, delta, veritical, horizontal);
+        tud_hid_n_mouse_report(ITF_NUM_MOUSE, report_id, button_mask, delta, delta, vertical, horizontal);
       }
     }
   }
@@ -175,13 +179,13 @@ void tud_hid_set_protocol_cb(uint8_t instance, uint8_t protocol)
   (void) protocol;
 
   // nothing to do since we use the same compatible boot report for both Boot and Report mode.
-  // TOOD set a indicator for user
+  // TODO set a indicator for user
 }
 
 // Invoked when sent REPORT successfully to host
 // Application can use this to send the next report
 // Note: For composite reports, report[0] is report ID
-void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, /*uint16_t*/ uint8_t len)
+void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, uint16_t len)
 {
   (void) instance;
   (void) report;
diff --git a/examples/device/hid_boot_interface/src/usb_descriptors.c b/examples/device/hid_boot_interface/src/usb_descriptors.c
index a0d7e9f15..d68ef16d9 100644
--- a/examples/device/hid_boot_interface/src/usb_descriptors.c
+++ b/examples/device/hid_boot_interface/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -130,51 +131,63 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/hid_boot_interface/src/usb_descriptors.h b/examples/device/hid_boot_interface/src/usb_descriptors.h
index 57cf0e2c0..6fee9e223 100644
--- a/examples/device/hid_boot_interface/src/usb_descriptors.h
+++ b/examples/device/hid_boot_interface/src/usb_descriptors.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
diff --git a/examples/device/hid_composite/CMakeLists.txt b/examples/device/hid_composite/CMakeLists.txt
index abc4d91da..a01eb3456 100644
--- a/examples/device/hid_composite/CMakeLists.txt
+++ b/examples/device/hid_composite/CMakeLists.txt
@@ -1,14 +1,18 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
 
@@ -23,6 +27,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/hid_composite/Makefile b/examples/device/hid_composite/Makefile
index 69b633fea..1b4d398cf 100644
--- a/examples/device/hid_composite/Makefile
+++ b/examples/device/hid_composite/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/hid_composite/src/main.c b/examples/device/hid_composite/src/main.c
index f7d76cfc7..dcf13079f 100644
--- a/examples/device/hid_composite/src/main.c
+++ b/examples/device/hid_composite/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #include "usb_descriptors.h"
@@ -60,6 +60,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
@@ -67,8 +71,6 @@ int main(void)
 
     hid_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -99,7 +101,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
@@ -225,7 +227,7 @@ void hid_task(void)
 // Invoked when sent REPORT successfully to host
 // Application can use this to send the next report
 // Note: For composite reports, report[0] is report ID
-void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, /*uint16_t*/ uint8_t len)
+void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, uint16_t len)
 {
   (void) instance;
   (void) len;
diff --git a/examples/device/hid_composite/src/usb_descriptors.c b/examples/device/hid_composite/src/usb_descriptors.c
index 2988baee2..e174db46d 100644
--- a/examples/device/hid_composite/src/usb_descriptors.c
+++ b/examples/device/hid_composite/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -177,51 +178,63 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/hid_composite/src/usb_descriptors.h b/examples/device/hid_composite/src/usb_descriptors.h
index ca8925ad9..e733d31dd 100644
--- a/examples/device/hid_composite/src/usb_descriptors.h
+++ b/examples/device/hid_composite/src/usb_descriptors.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
diff --git a/examples/device/hid_composite_freertos/CMakeLists.txt b/examples/device/hid_composite_freertos/CMakeLists.txt
index ed734b954..eb22014fb 100644
--- a/examples/device/hid_composite_freertos/CMakeLists.txt
+++ b/examples/device/hid_composite_freertos/CMakeLists.txt
@@ -1,17 +1,34 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
-# use BOARD-Directory name for project id
-get_filename_component(PROJECT ${CMAKE_CURRENT_SOURCE_DIR} NAME)
-set(PROJECT ${BOARD}-${PROJECT})
+include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
-# TOP is absolute path to root directory of TinyUSB git repo
-set(TOP "../../..")
-get_filename_component(TOP "${TOP}" REALPATH)
+# gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
+family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-# Check for -DFAMILY=
-if(FAMILY MATCHES "^esp32s[2-3]")
-  include(${TOP}/hw/bsp/${FAMILY}/family.cmake)
-  project(${PROJECT})
-else()
-  message(FATAL_ERROR "Invalid FAMILY specified: ${FAMILY}")
+project(${PROJECT} C CXX ASM)
+
+# Checks this example is valid for the family and initializes the project
+family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
 endif()
+
+add_executable(${PROJECT})
+
+# Example source
+target_sources(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/freertos_hook.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
+
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
+
+# Configure compilation flags and libraries for the example with FreeRTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} freertos)
diff --git a/examples/device/hid_composite_freertos/Makefile b/examples/device/hid_composite_freertos/Makefile
index 6c8c43ddd..add9e9814 100644
--- a/examples/device/hid_composite_freertos/Makefile
+++ b/examples/device/hid_composite_freertos/Makefile
@@ -1,23 +1,23 @@
 DEPS_SUBMODULES += lib/FreeRTOS-Kernel
 
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 FREERTOS_SRC = lib/FreeRTOS-Kernel
+FREERTOS_PORTABLE_PATH= $(FREERTOS_SRC)/portable/$(if $(USE_IAR),IAR,GCC)
 
 INC += \
 	src \
 	src/FreeRTOSConfig \
 	$(TOP)/hw \
 	$(TOP)/$(FREERTOS_SRC)/include \
-	$(TOP)/$(FREERTOS_SRC)/portable/GCC/$(FREERTOS_PORT)	
+	$(TOP)/$(FREERTOS_PORTABLE_SRC)
 
 # Example source
 EXAMPLE_SOURCE = \
 	src/freertos_hook.c \
 	src/main.c \
 	src/usb_descriptors.c
-	
+
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
 # FreeRTOS source, all files in port folder
@@ -26,12 +26,22 @@ SRC_C += \
 	$(FREERTOS_SRC)/queue.c \
 	$(FREERTOS_SRC)/tasks.c \
 	$(FREERTOS_SRC)/timers.c \
-	$(subst ../../../,,$(wildcard ../../../$(FREERTOS_SRC)/portable/GCC/$(FREERTOS_PORT)/*.c))
+	$(subst $(TOP)/,,$(wildcard $(TOP)/$(FREERTOS_PORTABLE_SRC)/*.c))
+
+SRC_S += \
+	$(subst $(TOP)/,,$(wildcard $(TOP)/$(FREERTOS_PORTABLE_SRC)/*.s))
+
+# include heap manage if configSUPPORT_DYNAMIC_ALLOCATION = 1
+# SRC_C += $(FREERTOS_SRC)/portable/MemMang/heap_1.c
+# CFLAGS += -Wno-error=sign-compare
+
+# Suppress FreeRTOSConfig.h warnings
+CFLAGS_GCC += -Wno-error=redundant-decls
 
-# Suppress FreeRTOS warnings
-CFLAGS += -Wno-error=cast-qual -Wno-error=redundant-decls
+# Suppress FreeRTOS source warnings
+CFLAGS_GCC += -Wno-error=cast-qual
 
 # FreeRTOS (lto + Os) linker issue
-LDFLAGS += -Wl,--undefined=vTaskSwitchContext
+LDFLAGS_GCC += -Wl,--undefined=vTaskSwitchContext
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/hid_composite_freertos/skip.txt b/examples/device/hid_composite_freertos/skip.txt
index 1ee51a9d4..a6f96b288 100644
--- a/examples/device/hid_composite_freertos/skip.txt
+++ b/examples/device/hid_composite_freertos/skip.txt
@@ -1,3 +1,4 @@
+mcu:CH32V307
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103
@@ -7,5 +8,6 @@ mcu:RP2040
 mcu:SAMD11
 mcu:SAMX7X
 mcu:VALENTYUSB_EPTRI
+mcu:RAXXX
 family:broadcom_32bit
-family:broadcom_64bit
\ No newline at end of file
+family:broadcom_64bit
diff --git a/examples/device/hid_composite_freertos/src/CMakeLists.txt b/examples/device/hid_composite_freertos/src/CMakeLists.txt
index 25da8fcd7..6d912854f 100644
--- a/examples/device/hid_composite_freertos/src/CMakeLists.txt
+++ b/examples/device/hid_composite_freertos/src/CMakeLists.txt
@@ -1,35 +1,3 @@
 idf_component_register(SRCS "main.c" "usb_descriptors.c"
                     INCLUDE_DIRS "."
-                    REQUIRES freertos soc)
-
-file(TO_NATIVE_PATH "${TOP}/hw/bsp/${FAMILY}/boards/${BOARD}/board.cmake" board_cmake)
-
-if(EXISTS ${board_cmake})
-    include(${board_cmake})
-endif()
-
-target_include_directories(${COMPONENT_TARGET} PUBLIC
-  "${TOP}/hw"
-  "${TOP}/src"
-)
-
-target_compile_definitions(${COMPONENT_TARGET} PUBLIC
-  ESP_PLATFORM
-)
-
-target_sources(${COMPONENT_TARGET} PUBLIC
-  "${TOP}/src/tusb.c"
-  "${TOP}/src/common/tusb_fifo.c"
-  "${TOP}/src/device/usbd.c"
-  "${TOP}/src/device/usbd_control.c"
-  "${TOP}/src/class/cdc/cdc_device.c"
-  "${TOP}/src/class/dfu/dfu_rt_device.c"
-  "${TOP}/src/class/hid/hid_device.c"
-  "${TOP}/src/class/midi/midi_device.c"
-  "${TOP}/src/class/msc/msc_device.c"
-  "${TOP}/src/class/net/ecm_rndis_device.c"
-  "${TOP}/src/class/net/ncm_device.c"
-  "${TOP}/src/class/usbtmc/usbtmc_device.c"
-  "${TOP}/src/class/vendor/vendor_device.c"
-  "${TOP}/src/portable/synopsys/dwc2/dcd_dwc2.c"
-)
+                    REQUIRES boards tinyusb_src)
diff --git a/examples/device/hid_composite_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h b/examples/device/hid_composite_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
index bfdf1e926..6cc7a6577 100644
--- a/examples/device/hid_composite_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
+++ b/examples/device/hid_composite_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
@@ -42,20 +42,26 @@
  * See http://www.freertos.org/a00110.html.
  *----------------------------------------------------------*/
 
+// skip if included from IAR assembler
+#ifndef __IASMARM__
+
 // Include MCU header
 #include "bsp/board_mcu.h"
 
 #if CFG_TUSB_MCU == OPT_MCU_ESP32S2 || CFG_TUSB_MCU == OPT_MCU_ESP32S3
-#error "ESP32-Sx should use IDF's FreeRTOSConfig.h"
+  #error "ESP32-Sx should use IDF's FreeRTOSConfig.h"
 #endif
 
+// TODO fix later
 #if CFG_TUSB_MCU == OPT_MCU_MM32F327X
-  // TODO fix/remove later  
   extern u32 SystemCoreClock;
 #else
+  // FIXME cause redundant-decls warnings
   extern uint32_t SystemCoreClock;
 #endif
 
+#endif
+
 /* Cortex M23/M33 port configuration. */
 #define configENABLE_MPU								        0
 #define configENABLE_FPU								        1
@@ -68,14 +74,14 @@
 #define configTICK_RATE_HZ                      ( 1000 )
 #define configMAX_PRIORITIES                    ( 5 )
 #define configMINIMAL_STACK_SIZE                ( 128 )
-#define configTOTAL_HEAP_SIZE                   ( 0*1024 ) // dynamic is not used
+#define configTOTAL_HEAP_SIZE                   ( configSUPPORT_DYNAMIC_ALLOCATION*4*1024 )
 #define configMAX_TASK_NAME_LEN                 16
 #define configUSE_16_BIT_TICKS                  0
 #define configIDLE_SHOULD_YIELD                 1
 #define configUSE_MUTEXES                       1
 #define configUSE_RECURSIVE_MUTEXES             1
 #define configUSE_COUNTING_SEMAPHORES           1
-#define configQUEUE_REGISTRY_SIZE               2
+#define configQUEUE_REGISTRY_SIZE               4
 #define configUSE_QUEUE_SETS                    0
 #define configUSE_TIME_SLICING                  0
 #define configUSE_NEWLIB_REENTRANT              0
@@ -90,6 +96,7 @@
 #define configUSE_TICK_HOOK                    0
 #define configUSE_MALLOC_FAILED_HOOK           0 // cause nested extern warning
 #define configCHECK_FOR_STACK_OVERFLOW         2
+#define configCHECK_HANDLER_INSTALLATION       0
 
 /* Run time and task stats gathering related definitions. */
 #define configGENERATE_RUN_TIME_STATS          0
@@ -124,29 +131,12 @@
 #define INCLUDE_xEventGroupSetBitFromISR       0
 #define INCLUDE_xTimerPendFunctionCall         0
 
-/* Define to trap errors during development. */
-// Halt CPU (breakpoint) when hitting error, only apply for Cortex M3, M4, M7
-#if defined(__ARM_ARCH_7M__) || defined (__ARM_ARCH_7EM__)
-  #define configASSERT(_exp) \
-    do {\
-      if ( !(_exp) ) { \
-        volatile uint32_t* ARM_CM_DHCSR =  ((volatile uint32_t*) 0xE000EDF0UL); /* Cortex M CoreDebug->DHCSR */ \
-        if ( (*ARM_CM_DHCSR) & 1UL ) {  /* Only halt mcu if debugger is attached */ \
-          taskDISABLE_INTERRUPTS(); \
-           __asm("BKPT #0\n"); \
-        }\
-      }\
-    } while(0)
-#else
-  #define configASSERT( x )
-#endif
-
 #ifdef __RX__
 /* Renesas RX series */
-#define vSoftwareInterruptISR					INT_Excep_ICU_SWINT
-#define vTickISR								INT_Excep_CMT0_CMI0
-#define configPERIPHERAL_CLOCK_HZ				(configCPU_CLOCK_HZ/2)
-#define configKERNEL_INTERRUPT_PRIORITY			1
+#define vSoftwareInterruptISR					        INT_Excep_ICU_SWINT
+#define vTickISR								              INT_Excep_CMT0_CMI0
+#define configPERIPHERAL_CLOCK_HZ				      (configCPU_CLOCK_HZ/2)
+#define configKERNEL_INTERRUPT_PRIORITY			  1
 #define configMAX_SYSCALL_INTERRUPT_PRIORITY	4
 
 #else
@@ -162,9 +152,18 @@
 #if defined(__NVIC_PRIO_BITS)
   // For Cortex-M specific: __NVIC_PRIO_BITS is defined in core_cmx.h
 	#define configPRIO_BITS       __NVIC_PRIO_BITS
+
 #elif defined(__ECLIC_INTCTLBITS)
   // RISC-V Bumblebee core from nuclei
   #define configPRIO_BITS       __ECLIC_INTCTLBITS
+
+#elif defined(__IASMARM__)
+  // FIXME: IAR Assembler cannot include mcu header directly to get __NVIC_PRIO_BITS.
+  // Therefore we will hard coded it to minimum value of 2 to get pass ci build.
+  // IAR user must update this to correct value of the target MCU
+  #message "configPRIO_BITS is hard coded to 2 to pass IAR build only. User should update it per MCU"
+  #define configPRIO_BITS       2
+
 #else
   #error "FreeRTOS configPRIO_BITS to be defined"
 #endif
diff --git a/examples/device/hid_composite_freertos/src/main.c b/examples/device/hid_composite_freertos/src/main.c
index b67c10937..ff2cb635e 100644
--- a/examples/device/hid_composite_freertos/src/main.c
+++ b/examples/device/hid_composite_freertos/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -53,6 +53,8 @@
   #define USBD_STACK_SIZE    (3*configMINIMAL_STACK_SIZE/2) * (CFG_TUSB_DEBUG ? 2 : 1)
 #endif
 
+#define HID_STACK_SZIE      configMINIMAL_STACK_SIZE
+
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF PROTYPES
 //--------------------------------------------------------------------+
@@ -68,19 +70,18 @@ enum  {
   BLINK_SUSPENDED = 2500,
 };
 
-// static timer
+// static timer & task
+#if configSUPPORT_STATIC_ALLOCATION
 StaticTimer_t blinky_tmdef;
-TimerHandle_t blinky_tm;
 
-// static task
 StackType_t  usb_device_stack[USBD_STACK_SIZE];
 StaticTask_t usb_device_taskdef;
 
-// static task for hid
-#define HID_STACK_SZIE      configMINIMAL_STACK_SIZE
 StackType_t  hid_stack[HID_STACK_SZIE];
 StaticTask_t hid_taskdef;
+#endif
 
+TimerHandle_t blinky_tm;
 
 void led_blinky_cb(TimerHandle_t xTimer);
 void usb_device_task(void* param);
@@ -94,15 +95,22 @@ int main(void)
 {
   board_init();
 
+#if configSUPPORT_STATIC_ALLOCATION
   // soft timer for blinky
   blinky_tm = xTimerCreateStatic(NULL, pdMS_TO_TICKS(BLINK_NOT_MOUNTED), true, NULL, led_blinky_cb, &blinky_tmdef);
-  xTimerStart(blinky_tm, 0);
 
   // Create a task for tinyusb device stack
-  (void) xTaskCreateStatic( usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);
+  xTaskCreateStatic(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);
 
   // Create HID task
-  (void) xTaskCreateStatic( hid_task, "hid", HID_STACK_SZIE, NULL, configMAX_PRIORITIES-2, hid_stack, &hid_taskdef);
+  xTaskCreateStatic(hid_task, "hid", HID_STACK_SZIE, NULL, configMAX_PRIORITIES-2, hid_stack, &hid_taskdef);
+#else
+  blinky_tm = xTimerCreate(NULL, pdMS_TO_TICKS(BLINK_NOT_MOUNTED), true, NULL, led_blinky_cb);
+  xTaskCreate(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, NULL);
+  xTaskCreate(hid_task, "hid", HID_STACK_SZIE, NULL, configMAX_PRIORITIES-2, NULL);
+#endif
+
+  xTimerStart(blinky_tm, 0);
 
   // skip starting scheduler (and return) for ESP32-S2 or ESP32-S3
 #if !TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
@@ -130,6 +138,10 @@ void usb_device_task(void* param)
   // Otherwise it could cause kernel issue since USB IRQ handler does use RTOS queue API.
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   // RTOS forever loop
   while (1)
   {
@@ -168,7 +180,14 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_MOUNTED), 0);
+  if (tud_mounted())
+  {
+    xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_MOUNTED), 0);
+  }
+  else
+  {
+    xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_NOT_MOUNTED), 0);
+  }
 }
 
 //--------------------------------------------------------------------+
@@ -294,7 +313,7 @@ void hid_task(void* param)
 // Invoked when sent REPORT successfully to host
 // Application can use this to send the next report
 // Note: For composite reports, report[0] is report ID
-void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, /*uint16_t*/ uint8_t len)
+void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, uint16_t len)
 {
   (void) instance;
   (void) len;
diff --git a/examples/device/hid_composite_freertos/src/tusb_config.h b/examples/device/hid_composite_freertos/src/tusb_config.h
index 935ae9453..3ba9bf311 100644
--- a/examples/device/hid_composite_freertos/src/tusb_config.h
+++ b/examples/device/hid_composite_freertos/src/tusb_config.h
@@ -54,7 +54,9 @@
 #endif
 
 // This examples use FreeRTOS
+#ifndef CFG_TUSB_OS
 #define CFG_TUSB_OS           OPT_OS_FREERTOS
+#endif
 
 // Espressif IDF requires "freertos/" prefix in include path
 #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
diff --git a/examples/device/hid_composite_freertos/src/usb_descriptors.c b/examples/device/hid_composite_freertos/src/usb_descriptors.c
index 4df12d3db..85820de55 100644
--- a/examples/device/hid_composite_freertos/src/usb_descriptors.c
+++ b/examples/device/hid_composite_freertos/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -175,51 +176,63 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/hid_composite_freertos/src/usb_descriptors.h b/examples/device/hid_composite_freertos/src/usb_descriptors.h
index ca8925ad9..e733d31dd 100644
--- a/examples/device/hid_composite_freertos/src/usb_descriptors.h
+++ b/examples/device/hid_composite_freertos/src/usb_descriptors.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
diff --git a/examples/device/hid_generic_inout/CMakeLists.txt b/examples/device/hid_generic_inout/CMakeLists.txt
index abc4d91da..a01eb3456 100644
--- a/examples/device/hid_generic_inout/CMakeLists.txt
+++ b/examples/device/hid_generic_inout/CMakeLists.txt
@@ -1,14 +1,18 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
 
@@ -23,6 +27,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/hid_generic_inout/Makefile b/examples/device/hid_generic_inout/Makefile
index 69b633fea..1b4d398cf 100644
--- a/examples/device/hid_generic_inout/Makefile
+++ b/examples/device/hid_generic_inout/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/hid_generic_inout/hid_test.js b/examples/device/hid_generic_inout/hid_test.js
index daa958fd5..16bc723e2 100644
--- a/examples/device/hid_generic_inout/hid_test.js
+++ b/examples/device/hid_generic_inout/hid_test.js
@@ -48,7 +48,7 @@ if( deviceInfo ) {
 
 
 function anySupportedBoard(d) {
-	
+
 	for (var key in boards) {
 	    if (boards.hasOwnProperty(key)) {
 	        if (isDevice(boards[key],d)) {
@@ -65,4 +65,3 @@ function isDevice(board,d){
 	// product id 0xff is matches all
 	return d.vendorId==board[0] && (d.productId==board[1] || board[1] == 0xFFFF);
 }
-
diff --git a/examples/device/hid_generic_inout/hid_test.py b/examples/device/hid_generic_inout/hid_test.py
index 21fd3f421..5bdba9db0 100644
--- a/examples/device/hid_generic_inout/hid_test.py
+++ b/examples/device/hid_generic_inout/hid_test.py
@@ -13,8 +13,8 @@ for vid in  USB_VID:
         if dev:
             while True:
                 # Get input from console and encode to UTF8 for array of chars.
-                # hid generic inout is single report therefore by HIDAPI requirement
-                # it must be preceeded with 0x00 as dummy reportID
+                # hid generic in/out is single report therefore by HIDAPI requirement
+                # it must be preceded, with 0x00 as dummy reportID
                 str_out = b'\x00'
                 str_out += input("Send text to HID Device : ").encode('utf-8')
                 dev.write(str_out)
diff --git a/examples/device/hid_generic_inout/src/main.c b/examples/device/hid_generic_inout/src/main.c
index 5b7daf118..cfa9f6283 100644
--- a/examples/device/hid_generic_inout/src/main.c
+++ b/examples/device/hid_generic_inout/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* This example demonstrate HID Generic raw Input & Output.
@@ -83,13 +83,15 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
     led_blinking_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -120,7 +122,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
diff --git a/examples/device/hid_generic_inout/src/usb_descriptors.c b/examples/device/hid_generic_inout/src/usb_descriptors.c
index c2b4792c8..64f6d17ae 100644
--- a/examples/device/hid_generic_inout/src/usb_descriptors.c
+++ b/examples/device/hid_generic_inout/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -103,7 +104,7 @@ uint8_t const desc_configuration[] =
   // Config number, interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
 
-  // Interface number, string index, protocol, report descriptor len, EP In & Out address, size & polling interval
+  // Interface number, string index, protocol, report descriptor len, EP Out & In address, size & polling interval
   TUD_HID_INOUT_DESCRIPTOR(ITF_NUM_HID, 0, HID_ITF_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, 0x80 | EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 10)
 };
 
@@ -120,51 +121,63 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/hid_multiple_interface/CMakeLists.txt b/examples/device/hid_multiple_interface/CMakeLists.txt
index abc4d91da..a01eb3456 100644
--- a/examples/device/hid_multiple_interface/CMakeLists.txt
+++ b/examples/device/hid_multiple_interface/CMakeLists.txt
@@ -1,14 +1,18 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
 
@@ -23,6 +27,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/hid_multiple_interface/Makefile b/examples/device/hid_multiple_interface/Makefile
index 69b633fea..1b4d398cf 100644
--- a/examples/device/hid_multiple_interface/Makefile
+++ b/examples/device/hid_multiple_interface/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/hid_multiple_interface/src/main.c b/examples/device/hid_multiple_interface/src/main.c
index 29ba74398..30b4ae055 100644
--- a/examples/device/hid_multiple_interface/src/main.c
+++ b/examples/device/hid_multiple_interface/src/main.c
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 //--------------------------------------------------------------------+
@@ -64,6 +64,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
@@ -71,8 +75,6 @@ int main(void)
 
     hid_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -103,7 +105,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
diff --git a/examples/device/hid_multiple_interface/src/usb_descriptors.c b/examples/device/hid_multiple_interface/src/usb_descriptors.c
index 42471a961..86f567e8e 100644
--- a/examples/device/hid_multiple_interface/src/usb_descriptors.c
+++ b/examples/device/hid_multiple_interface/src/usb_descriptors.c
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -136,53 +137,65 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 },  // 0: is supported language is English (0x0409)
   "TinyUSB",                      // 1: Manufacturer
   "TinyUSB Device",               // 2: Product
-  "123456",                       // 3: Serials, should use chip ID
+  NULL,                           // 3: Serials will use unique ID if possible
   "Keyboard Interface",           // 4: Interface 1 String
   "Mouse Interface",              // 5: Interface 2 String
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
 
-  uint8_t chr_count;
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/midi_test/CMakeLists.txt b/examples/device/midi_test/CMakeLists.txt
index abc4d91da..e51f14c02 100644
--- a/examples/device/midi_test/CMakeLists.txt
+++ b/examples/device/midi_test/CMakeLists.txt
@@ -1,17 +1,20 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
 
 add_executable(${PROJECT})
-
 # Example source
 target_sources(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
@@ -23,6 +26,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/midi_test/Makefile b/examples/device/midi_test/Makefile
index 5a455078e..7fa475da5 100644
--- a/examples/device/midi_test/Makefile
+++ b/examples/device/midi_test/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/midi_test/src/main.c b/examples/device/midi_test/src/main.c
index 3310348bd..b1d51598f 100644
--- a/examples/device/midi_test/src/main.c
+++ b/examples/device/midi_test/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* This MIDI example send sequence of note (on/off) repeatedly. To test on PC, you need to install
@@ -65,15 +65,16 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
     led_blinking_task();
     midi_task();
   }
-
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -104,7 +105,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
diff --git a/examples/device/midi_test/src/usb_descriptors.c b/examples/device/midi_test/src/usb_descriptors.c
index c84a873b1..9781d3d6f 100644
--- a/examples/device/midi_test/src/usb_descriptors.c
+++ b/examples/device/midi_test/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,13 +23,14 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
  * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
  *
  * Auto ProductID layout's Bitmap:
- *   [MSB]       MIDI | HID | MSC | CDC          [LSB]
+ *   [MSB]         HID | MSC | CDC          [LSB]
  */
 #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
@@ -133,51 +134,63 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/msc_dual_lun/CMakeLists.txt b/examples/device/msc_dual_lun/CMakeLists.txt
index 9e834ae21..e69fead35 100644
--- a/examples/device/msc_dual_lun/CMakeLists.txt
+++ b/examples/device/msc_dual_lun/CMakeLists.txt
@@ -1,29 +1,34 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
 target_sources(${PROJECT} PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/msc_disk_dual.c
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
-        )
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/msc_disk_dual.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
 
 # Example include
 target_include_directories(${PROJECT} PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src
-        )
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/msc_dual_lun/Makefile b/examples/device/msc_dual_lun/Makefile
index 5a455078e..7fa475da5 100644
--- a/examples/device/msc_dual_lun/Makefile
+++ b/examples/device/msc_dual_lun/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/msc_dual_lun/skip.txt b/examples/device/msc_dual_lun/skip.txt
index 3549c702a..a9e3a99b1 100644
--- a/examples/device/msc_dual_lun/skip.txt
+++ b/examples/device/msc_dual_lun/skip.txt
@@ -1,2 +1,3 @@
 mcu:SAMD11
-mcu:MKL25ZXX
\ No newline at end of file
+mcu:MKL25ZXX
+family:espressif
diff --git a/examples/device/msc_dual_lun/src/main.c b/examples/device/msc_dual_lun/src/main.c
index 96790d20c..de402d3da 100644
--- a/examples/device/msc_dual_lun/src/main.c
+++ b/examples/device/msc_dual_lun/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 //--------------------------------------------------------------------+
@@ -57,13 +57,15 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
     led_blinking_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -94,7 +96,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
diff --git a/examples/device/msc_dual_lun/src/msc_disk_dual.c b/examples/device/msc_dual_lun/src/msc_disk_dual.c
index 2b773b43b..4f0f6410f 100644
--- a/examples/device/msc_dual_lun/src/msc_disk_dual.c
+++ b/examples/device/msc_dual_lun/src/msc_disk_dual.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,7 +23,7 @@
  *
  */
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #if CFG_TUD_MSC
diff --git a/examples/device/msc_dual_lun/src/usb_descriptors.c b/examples/device/msc_dual_lun/src/usb_descriptors.c
index 68a671c91..c0610945f 100644
--- a/examples/device/msc_dual_lun/src/usb_descriptors.c
+++ b/examples/device/msc_dual_lun/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -90,6 +91,12 @@ enum
   #define EPNUM_MSC_OUT   0x01
   #define EPNUM_MSC_IN    0x82
 
+#elif CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X
+  // FT9XX doesn't support a same endpoint number with different direction IN and OUT
+  //    e.g EP1 OUT & EP1 IN cannot exist together
+  #define EPNUM_MSC_OUT   0x01
+  #define EPNUM_MSC_IN    0x82
+
 #else
   #define EPNUM_MSC_OUT   0x01
   #define EPNUM_MSC_IN    0x81
@@ -135,51 +142,63 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456789012",                // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/net_lwip_webserver/CMakeLists.txt b/examples/device/net_lwip_webserver/CMakeLists.txt
index 9fe1a325e..a16b8bd71 100644
--- a/examples/device/net_lwip_webserver/CMakeLists.txt
+++ b/examples/device/net_lwip_webserver/CMakeLists.txt
@@ -1,83 +1,93 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
-set(TOP "../../..")
-get_filename_component(TOP "${TOP}" REALPATH)
+include(${CMAKE_CURRENT_LIST_DIR}/../../../hw/bsp/family_support.cmake)
 
-if (EXISTS ${TOP}/lib/lwip/src)
-    include(${TOP}/hw/bsp/family_support.cmake)
+# gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
+family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-    # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
-    family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
+set(LWIP ${TOP}/lib/lwip)
+if (NOT EXISTS ${LWIP}/src)
+  family_example_missing_dependency(${PROJECT} "lib/lwip")
+  return()
+endif()
 
-    project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
-    # Checks this example is valid for the family and initializes the project
-    family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+# Checks this example is valid for the family and initializes the project
+family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
-    add_executable(${PROJECT})
+add_executable(${PROJECT})
 
-    # Example source
-    target_sources(${PROJECT} PUBLIC
-            ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
-            ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
-            )
+# Example source
+target_sources(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_LIST_DIR}/src/main.c
+  ${CMAKE_CURRENT_LIST_DIR}/src/usb_descriptors.c
+  )
 
-    # Example include
-    target_include_directories(${PROJECT} PUBLIC
-            ${CMAKE_CURRENT_SOURCE_DIR}/src
-            ${TOP}/lib/lwip/src/include
-            ${TOP}/lib/lwip/src/include/ipv4
-            ${TOP}/lib/lwip/src/include/lwip/apps
-            ${TOP}/lib/networking
-            )
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_LIST_DIR}/src
+  ${LWIP}/src/include
+  ${LWIP}/src/include/ipv4
+  ${LWIP}/src/include/lwip/apps
+  ${TOP}/lib/networking
+  )
 
-    target_sources(${PROJECT} PUBLIC
-            ${TOP}/lib/lwip/src/core/altcp.c
-            ${TOP}/lib/lwip/src/core/altcp_alloc.c
-            ${TOP}/lib/lwip/src/core/altcp_tcp.c
-            ${TOP}/lib/lwip/src/core/def.c
-            ${TOP}/lib/lwip/src/core/dns.c
-            ${TOP}/lib/lwip/src/core/inet_chksum.c
-            ${TOP}/lib/lwip/src/core/init.c
-            ${TOP}/lib/lwip/src/core/ip.c
-            ${TOP}/lib/lwip/src/core/mem.c
-            ${TOP}/lib/lwip/src/core/memp.c
-            ${TOP}/lib/lwip/src/core/netif.c
-            ${TOP}/lib/lwip/src/core/pbuf.c
-            ${TOP}/lib/lwip/src/core/raw.c
-            ${TOP}/lib/lwip/src/core/stats.c
-            ${TOP}/lib/lwip/src/core/sys.c
-            ${TOP}/lib/lwip/src/core/tcp.c
-            ${TOP}/lib/lwip/src/core/tcp_in.c
-            ${TOP}/lib/lwip/src/core/tcp_out.c
-            ${TOP}/lib/lwip/src/core/timeouts.c
-            ${TOP}/lib/lwip/src/core/udp.c
-            ${TOP}/lib/lwip/src/core/ipv4/autoip.c
-            ${TOP}/lib/lwip/src/core/ipv4/dhcp.c
-            ${TOP}/lib/lwip/src/core/ipv4/etharp.c
-            ${TOP}/lib/lwip/src/core/ipv4/icmp.c
-            ${TOP}/lib/lwip/src/core/ipv4/igmp.c
-            ${TOP}/lib/lwip/src/core/ipv4/ip4.c
-            ${TOP}/lib/lwip/src/core/ipv4/ip4_addr.c
-            ${TOP}/lib/lwip/src/core/ipv4/ip4_frag.c
-            ${TOP}/lib/lwip/src/netif/ethernet.c
-            ${TOP}/lib/lwip/src/netif/slipif.c
-            ${TOP}/lib/lwip/src/apps/http/httpd.c
-            ${TOP}/lib/lwip/src/apps/http/fs.c
-            ${TOP}/lib/networking/dhserver.c
-            ${TOP}/lib/networking/dnserver.c
-            ${TOP}/lib/networking/rndis_reports.c
-            )
+# lib/networking sources
+target_sources(${PROJECT} PUBLIC
+  ${TOP}/lib/networking/dhserver.c
+  ${TOP}/lib/networking/dnserver.c
+  ${TOP}/lib/networking/rndis_reports.c
+  )
 
-    # due to warnings from other net source, we need to prevent error from some of the warnings options
-    target_compile_options(${PROJECT} PUBLIC
-        -Wno-error=null-dereference
-        -Wno-error=conversion
-        -Wno-error=sign-conversion
-        -Wno-error=sign-compare
-        )
+# lwip sources
+target_sources(${PROJECT} PUBLIC
+  ${LWIP}/src/core/altcp.c
+  ${LWIP}/src/core/altcp_alloc.c
+  ${LWIP}/src/core/altcp_tcp.c
+  ${LWIP}/src/core/def.c
+  ${LWIP}/src/core/dns.c
+  ${LWIP}/src/core/inet_chksum.c
+  ${LWIP}/src/core/init.c
+  ${LWIP}/src/core/ip.c
+  ${LWIP}/src/core/mem.c
+  ${LWIP}/src/core/memp.c
+  ${LWIP}/src/core/netif.c
+  ${LWIP}/src/core/pbuf.c
+  ${LWIP}/src/core/raw.c
+  ${LWIP}/src/core/stats.c
+  ${LWIP}/src/core/sys.c
+  ${LWIP}/src/core/tcp.c
+  ${LWIP}/src/core/tcp_in.c
+  ${LWIP}/src/core/tcp_out.c
+  ${LWIP}/src/core/timeouts.c
+  ${LWIP}/src/core/udp.c
+  ${LWIP}/src/core/ipv4/autoip.c
+  ${LWIP}/src/core/ipv4/dhcp.c
+  ${LWIP}/src/core/ipv4/etharp.c
+  ${LWIP}/src/core/ipv4/icmp.c
+  ${LWIP}/src/core/ipv4/igmp.c
+  ${LWIP}/src/core/ipv4/ip4.c
+  ${LWIP}/src/core/ipv4/ip4_addr.c
+  ${LWIP}/src/core/ipv4/ip4_frag.c
+  ${LWIP}/src/netif/ethernet.c
+  ${LWIP}/src/netif/slipif.c
+  ${LWIP}/src/apps/http/httpd.c
+  ${LWIP}/src/apps/http/fs.c
+  )
 
-    # Configure compilation flags and libraries for the example... see the corresponding function
-    # in hw/bsp/FAMILY/family.cmake for details.
-    family_configure_device_example(${PROJECT})
-endif()
\ No newline at end of file
+# due to warnings from other net source, we need to prevent error from some of the warnings options
+if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
+  target_compile_options(${PROJECT} PUBLIC
+    -Wno-error=null-dereference
+    -Wno-error=conversion
+    -Wno-error=sign-conversion
+    -Wno-error=sign-compare
+    )
+elseif (CMAKE_C_COMPILER_ID STREQUAL "IAR")
+
+endif ()
+
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/net_lwip_webserver/Makefile b/examples/device/net_lwip_webserver/Makefile
index 881866a56..22426ba0d 100644
--- a/examples/device/net_lwip_webserver/Makefile
+++ b/examples/device/net_lwip_webserver/Makefile
@@ -1,10 +1,9 @@
 DEPS_SUBMODULES += lib/lwip
 
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 # suppress warning caused by lwip
-CFLAGS += \
+CFLAGS_GCC += \
   -Wno-error=null-dereference \
   -Wno-error=unused-parameter \
   -Wno-error=unused-variable
@@ -68,4 +67,4 @@ SRC_C += \
   lib/networking/dnserver.c \
   lib/networking/rndis_reports.c
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/net_lwip_webserver/skip.txt b/examples/device/net_lwip_webserver/skip.txt
index 68761b058..75aa2ef14 100644
--- a/examples/device/net_lwip_webserver/skip.txt
+++ b/examples/device/net_lwip_webserver/skip.txt
@@ -4,7 +4,9 @@ mcu:MSP430x5xx
 mcu:NUC121
 mcu:SAMD11
 mcu:STM32L0
-mcu:MKL25ZXX
+mcu:KINETIS_KL
 family:broadcom_64bit
 family:broadcom_32bit
-board:curiosity_nano
\ No newline at end of file
+board:curiosity_nano
+board:frdm_kl25z
+family:espressif
diff --git a/examples/device/net_lwip_webserver/src/arch/bpstruct.h b/examples/device/net_lwip_webserver/src/arch/bpstruct.h
new file mode 100644
index 000000000..74ead358f
--- /dev/null
+++ b/examples/device/net_lwip_webserver/src/arch/bpstruct.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <[email protected]>
+ *
+ */
+
+#if defined(__ICCARM__)
+#pragma pack(1)
+#endif
diff --git a/examples/device/net_lwip_webserver/src/arch/cc.h b/examples/device/net_lwip_webserver/src/arch/cc.h
index 56a0cacf7..9f30b91cb 100644
--- a/examples/device/net_lwip_webserver/src/arch/cc.h
+++ b/examples/device/net_lwip_webserver/src/arch/cc.h
@@ -1,8 +1,8 @@
 /*
  * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
- * All rights reserved. 
- * 
- * Redistribution and use in source and binary forms, with or without modification, 
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright notice,
@@ -11,21 +11,21 @@
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission. 
+ *    derived from this software without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
- * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  * OF SUCH DAMAGE.
  *
  * This file is part of the lwIP TCP/IP stack.
- * 
+ *
  * Author: Adam Dunkels <[email protected]>
  *
  */
@@ -42,7 +42,7 @@ typedef int sys_prot_t;
 #if defined (__ICCARM__)
 
 #define PACK_STRUCT_BEGIN
-#define PACK_STRUCT_STRUCT 
+#define PACK_STRUCT_STRUCT
 #define PACK_STRUCT_END
 #define PACK_STRUCT_FIELD(x) x
 #define PACK_STRUCT_USE_INCLUDES
@@ -50,7 +50,7 @@ typedef int sys_prot_t;
 #elif defined (__CC_ARM)
 
 #define PACK_STRUCT_BEGIN __packed
-#define PACK_STRUCT_STRUCT 
+#define PACK_STRUCT_STRUCT
 #define PACK_STRUCT_END
 #define PACK_STRUCT_FIELD(x) x
 
diff --git a/examples/device/net_lwip_webserver/src/arch/epstruct.h b/examples/device/net_lwip_webserver/src/arch/epstruct.h
new file mode 100644
index 000000000..f6390959e
--- /dev/null
+++ b/examples/device/net_lwip_webserver/src/arch/epstruct.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <[email protected]>
+ *
+ */
+
+#if defined(__ICCARM__)
+#pragma pack()
+#endif
diff --git a/examples/device/net_lwip_webserver/src/lwipopts.h b/examples/device/net_lwip_webserver/src/lwipopts.h
index a215017c7..336c9243d 100644
--- a/examples/device/net_lwip_webserver/src/lwipopts.h
+++ b/examples/device/net_lwip_webserver/src/lwipopts.h
@@ -1,8 +1,8 @@
 /*
  * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
- * All rights reserved. 
- * 
- * Redistribution and use in source and binary forms, with or without modification, 
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright notice,
@@ -11,21 +11,21 @@
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission. 
+ *    derived from this software without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
- * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  * OF SUCH DAMAGE.
  *
  * This file is part of the lwIP TCP/IP stack.
- * 
+ *
  * Author: Simon Goldschmidt
  *
  */
diff --git a/examples/device/net_lwip_webserver/src/main.c b/examples/device/net_lwip_webserver/src/main.c
index 33b4d38b6..7d98aacbc 100644
--- a/examples/device/net_lwip_webserver/src/main.c
+++ b/examples/device/net_lwip_webserver/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Peter Lawrence
@@ -39,11 +39,11 @@ and likely their manufacturer has not tested such functionality.  Some code work
 The smartphone may only have an ECM driver, but refuse to automatically pick ECM (unlike the OSes above);
 try modifying ./examples/devices/net_lwip_webserver/usb_descriptors.c so that CONFIG_ID_ECM is default.
 
-The smartphone may be artificially picky about which Ethernet MAC address to recognize; if this happens, 
+The smartphone may be artificially picky about which Ethernet MAC address to recognize; if this happens,
 try changing the first byte of tud_network_mac_address[] below from 0x02 to 0x00 (clearing bit 1).
 */
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #include "dhserver.h"
@@ -64,7 +64,7 @@ static struct pbuf *received_frame;
 /* this is used by this code, ./class/net/net_driver.c, and usb_descriptors.c */
 /* ideally speaking, this should be generated from the hardware's unique ID (if available) */
 /* it is suggested that the first byte is 0x02 to indicate a link-local address */
-const uint8_t tud_network_mac_address[6] = {0x02,0x02,0x84,0x6A,0x96,0x00};
+uint8_t tud_network_mac_address[6] = {0x02,0x02,0x84,0x6A,0x96,0x00};
 
 /* network parameters of this MCU */
 static const ip4_addr_t ipaddr  = INIT_IP4(192, 168, 7, 1);
@@ -170,7 +170,7 @@ bool dns_query_proc(const char *name, ip4_addr_t *addr)
 
 bool tud_network_recv_cb(const uint8_t *src, uint16_t size)
 {
-  /* this shouldn't happen, but if we get another packet before 
+  /* this shouldn't happen, but if we get another packet before
   parsing the previous, we must signal our inability to accept it */
   if (received_frame) return false;
 
@@ -232,6 +232,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   /* initialize lwip, dhcp-server, dns-server, and http */
   init_lwip();
   while (!netif_is_up(&netif_data));
diff --git a/examples/device/net_lwip_webserver/src/usb_descriptors.c b/examples/device/net_lwip_webserver/src/usb_descriptors.c
index bee51790a..da628c8be 100644
--- a/examples/device/net_lwip_webserver/src/usb_descriptors.c
+++ b/examples/device/net_lwip_webserver/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -77,7 +78,7 @@ tusb_desc_device_t const desc_device =
     .bDeviceClass       = TUSB_CLASS_MISC,
     .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
     .bDeviceProtocol    = MISC_PROTOCOL_IAD,
-    
+
     .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
     .idVendor           = 0xCafe,
@@ -190,55 +191,56 @@ static char const* string_desc_arr [] =
   [STRID_LANGID]       = (const char[]) { 0x09, 0x04 }, // supported language is English (0x0409)
   [STRID_MANUFACTURER] = "TinyUSB",                     // Manufacturer
   [STRID_PRODUCT]      = "TinyUSB Device",              // Product
-  [STRID_SERIAL]       = "123456",                      // Serial
+  [STRID_SERIAL]       = NULL,                          // Serials will use unique ID if possible
   [STRID_INTERFACE]    = "TinyUSB Network Interface"    // Interface Description
 
   // STRID_MAC index is handled separately
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
-
   unsigned int chr_count = 0;
 
-  if (STRID_LANGID == index)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[STRID_LANGID], 2);
-    chr_count = 1;
-  }
-  else if (STRID_MAC == index)
-  {
-    // Convert MAC address into UTF-16
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-    for (unsigned i=0; i<sizeof(tud_network_mac_address); i++)
-    {
-      _desc_str[1+chr_count++] = "0123456789ABCDEF"[(tud_network_mac_address[i] >> 4) & 0xf];
-      _desc_str[1+chr_count++] = "0123456789ABCDEF"[(tud_network_mac_address[i] >> 0) & 0xf];
-    }
-  }
-  else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    case STRID_MAC:
+      // Convert MAC address into UTF-16
+      for (unsigned i=0; i<sizeof(tud_network_mac_address); i++) {
+        _desc_str[1+chr_count++] = "0123456789ABCDEF"[(tud_network_mac_address[i] >> 4) & 0xf];
+        _desc_str[1+chr_count++] = "0123456789ABCDEF"[(tud_network_mac_address[i] >> 0) & 0xf];
+      }
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > (TU_ARRAY_SIZE(_desc_str) - 1)) chr_count = TU_ARRAY_SIZE(_desc_str) - 1;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for (unsigned int i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
diff --git a/examples/device/uac2_headset/CMakeLists.txt b/examples/device/uac2_headset/CMakeLists.txt
index abc4d91da..e92a57148 100644
--- a/examples/device/uac2_headset/CMakeLists.txt
+++ b/examples/device/uac2_headset/CMakeLists.txt
@@ -1,15 +1,20 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
@@ -23,6 +28,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/uac2_headset/Makefile b/examples/device/uac2_headset/Makefile
index 5a455078e..7fa475da5 100644
--- a/examples/device/uac2_headset/Makefile
+++ b/examples/device/uac2_headset/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/uac2_headset/skip.txt b/examples/device/uac2_headset/skip.txt
index 70d8e8838..a2a76af0e 100644
--- a/examples/device/uac2_headset/skip.txt
+++ b/examples/device/uac2_headset/skip.txt
@@ -5,3 +5,4 @@ mcu:SAMD11
 mcu:SAME5X
 mcu:SAMG
 board:stm32l052dap52
+family:espressif
diff --git a/examples/device/uac2_headset/src/main.c b/examples/device/uac2_headset/src/main.c
index 003dc2a74..0ab72b2f3 100644
--- a/examples/device/uac2_headset/src/main.c
+++ b/examples/device/uac2_headset/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Jerzy Kasenberg
@@ -26,7 +26,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -79,8 +79,8 @@ static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
 
 // Audio controls
 // Current states
-int8_t mute[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX + 1];       // +1 for master channel 0
-int16_t volume[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX + 1];    // +1 for master channel 0
+int8_t mute[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX + 1];       // +1 for master channel 0
+int16_t volume[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX + 1];    // +1 for master channel 0
 
 // Buffer for microphone data
 int32_t mic_buf[CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ / 4];
@@ -105,6 +105,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   TU_LOG1("Headset running\r\n");
 
   while (1)
@@ -113,8 +117,6 @@ int main(void)
     audio_task();
     led_blinking_task();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -145,7 +147,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 // Helper for clock get requests
@@ -176,7 +178,7 @@ static bool tud_audio_clock_get_request(uint8_t rhport, audio_control_request_t
         rangef.subrange[i].bRes = 0;
         TU_LOG1("Range %d (%d, %d, %d)\r\n", i, (int)rangef.subrange[i].bMin, (int)rangef.subrange[i].bMax, (int)rangef.subrange[i].bRes);
       }
-      
+
       return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &rangef, sizeof(rangef));
     }
   }
diff --git a/examples/device/uac2_headset/src/tusb_config.h b/examples/device/uac2_headset/src/tusb_config.h
index 1a3e23e95..b770483dc 100644
--- a/examples/device/uac2_headset/src/tusb_config.h
+++ b/examples/device/uac2_headset/src/tusb_config.h
@@ -151,11 +151,11 @@ extern "C" {
 // EP and buffer size - for isochronous EP´s, the buffer and EP size are equal (different sizes would not make sense)
 #define CFG_TUD_AUDIO_ENABLE_EP_OUT               1
 
-#define CFG_TUD_AUDIO_UNC_1_FORMAT_1_EP_SZ_OUT    TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX)
-#define CFG_TUD_AUDIO_UNC_1_FORMAT_2_EP_SZ_OUT    TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX)
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT   TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX)
+#define CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_OUT   TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX)
 
-#define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ     TU_MAX(CFG_TUD_AUDIO_UNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_UNC_1_FORMAT_2_EP_SZ_OUT)*2
-#define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX        TU_MAX(CFG_TUD_AUDIO_UNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_UNC_1_FORMAT_2_EP_SZ_OUT) // Maximum EP IN size for all AS alternate settings used
+#define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ     TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_OUT)*2
+#define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX        TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_OUT) // Maximum EP IN size for all AS alternate settings used
 
 // Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
 #define CFG_TUD_AUDIO_FUNC_1_N_AS_INT 	          2
diff --git a/examples/device/uac2_headset/src/usb_descriptors.c b/examples/device/uac2_headset/src/usb_descriptors.c
index 10f5cbd27..6d1e6a23f 100644
--- a/examples/device/uac2_headset/src/usb_descriptors.c
+++ b/examples/device/uac2_headset/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Ha Thach (tinyusb.org)
@@ -24,6 +24,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -46,7 +47,7 @@ tusb_desc_device_t const desc_device =
     .bDescriptorType    = TUSB_DESC_DEVICE,
     .bcdUSB             = 0x0200,
 
-    // Use Interface Association Descriptor (IAD) for CDC
+    // Use Interface Association Descriptor (IAD) for Audio
     // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
     .bDeviceClass       = TUSB_CLASS_MISC,
     .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
@@ -93,6 +94,12 @@ uint8_t const * tud_descriptor_device_cb(void)
   #define EPNUM_AUDIO_IN    0x01
   #define EPNUM_AUDIO_OUT   0x02
 
+#elif CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X
+  // FT9XX doesn't support a same endpoint number with different direction IN and OUT
+  //    e.g EP1 OUT & EP1 IN cannot exist together
+  #define EPNUM_AUDIO_IN    0x01
+  #define EPNUM_AUDIO_OUT   0x02
+
 #else
   #define EPNUM_AUDIO_IN    0x01
   #define EPNUM_AUDIO_OUT   0x01
@@ -100,7 +107,7 @@ uint8_t const * tud_descriptor_device_cb(void)
 
 uint8_t const desc_configuration[] =
 {
-    // Interface count, string index, total length, attribute, power in mA
+    // Config number, interface count, string index, total length, attribute, power in mA
     TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
 
     // Interface number, string index, EP Out & EP In address, EP size
@@ -120,52 +127,65 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 },  // 0: is supported language is English (0x0409)
   "TinyUSB",                      // 1: Manufacturer
   "TinyUSB headset",              // 2: Product
-  "000001",                       // 3: Serials, should use chip ID
+  NULL,                           // 3: Serials will use unique ID if possible
   "TinyUSB Speakers",             // 4: Audio Interface
   "TinyUSB Microphone",           // 5: Audio Interface
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
-  (void)langid;
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
+  (void) langid;
+  size_t chr_count;
 
-  uint8_t chr_count;
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  if (index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }
-  else
-  {
-    // Convert ASCII string into UTF-16
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if (!(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0]))) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if (chr_count > 31) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    for (uint8_t i = 0; i < chr_count; i++)
-    {
-      _desc_str[1 + i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/uac2_headset/src/usb_descriptors.h b/examples/device/uac2_headset/src/usb_descriptors.h
index 342b4fac1..d7e170162 100644
--- a/examples/device/uac2_headset/src/usb_descriptors.h
+++ b/examples/device/uac2_headset/src/usb_descriptors.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Jerzy Kasenbreg
@@ -57,7 +57,7 @@ enum
     + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
     /* Interface 1, Alternate 0 */\
     + TUD_AUDIO_DESC_STD_AS_INT_LEN\
-    /* Interface 1, Alternate 0 */\
+    /* Interface 1, Alternate 1 */\
     + TUD_AUDIO_DESC_STD_AS_INT_LEN\
     + TUD_AUDIO_DESC_CS_AS_INT_LEN\
     + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
@@ -86,7 +86,7 @@ enum
 
 #define TUD_AUDIO_HEADSET_STEREO_DESCRIPTOR(_stridx, _epout, _epin) \
     /* Standard Interface Association Descriptor (IAD) */\
-    TUD_AUDIO_DESC_IAD(/*_firstitfs*/ ITF_NUM_AUDIO_CONTROL, /*_nitfs*/ 3, /*_stridx*/ 0x00),\
+    TUD_AUDIO_DESC_IAD(/*_firstitf*/ ITF_NUM_AUDIO_CONTROL, /*_nitfs*/ ITF_NUM_TOTAL, /*_stridx*/ 0x00),\
     /* Standard AC Interface Descriptor(4.7.1) */\
     TUD_AUDIO_DESC_STD_AC(/*_itfnum*/ ITF_NUM_AUDIO_CONTROL, /*_nEPs*/ 0x00, /*_stridx*/ _stridx),\
     /* Class-Specific AC Interface Header Descriptor(4.7.2) */\
@@ -114,7 +114,7 @@ enum
     /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
     TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX),\
     /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
-    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ADAPTIVE | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ADAPTIVE | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
     /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
     TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC, /*_lockdelay*/ 0x0001),\
     /* Interface 1, Alternate 2 - alternate interface for data streaming */\
@@ -124,7 +124,7 @@ enum
     /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
     TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_RX),\
     /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
-    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ADAPTIVE | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ADAPTIVE | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
     /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
     TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC, /*_lockdelay*/ 0x0001),\
     /* Standard AS Interface Descriptor(4.9.1) */\
@@ -138,7 +138,7 @@ enum
     /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
     TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_TX),\
     /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
-    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX), /*_interval*/ 0x01),\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX), /*_interval*/ 0x01),\
     /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
     TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000),\
     /* Interface 2, Alternate 2 - alternate interface for data streaming */\
@@ -148,7 +148,7 @@ enum
     /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
     TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_TX),\
     /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
-    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX), /*_interval*/ 0x01),\
+    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX), /*_interval*/ 0x01),\
     /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
     TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000)
 
diff --git a/examples/device/usbtmc/CMakeLists.txt b/examples/device/usbtmc/CMakeLists.txt
index c49603c26..a63ca2d81 100644
--- a/examples/device/usbtmc/CMakeLists.txt
+++ b/examples/device/usbtmc/CMakeLists.txt
@@ -1,15 +1,20 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
@@ -24,6 +29,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/usbtmc/Makefile b/examples/device/usbtmc/Makefile
index 69b633fea..1b4d398cf 100644
--- a/examples/device/usbtmc/Makefile
+++ b/examples/device/usbtmc/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
 	src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/usbtmc/skip.txt b/examples/device/usbtmc/skip.txt
index a43106cf0..ccff857ac 100644
--- a/examples/device/usbtmc/skip.txt
+++ b/examples/device/usbtmc/skip.txt
@@ -1 +1,2 @@
 mcu:BCM2835
+family:espressif
diff --git a/examples/device/usbtmc/src/main.c b/examples/device/usbtmc/src/main.c
index 6945d8743..9d8f0783d 100644
--- a/examples/device/usbtmc/src/main.c
+++ b/examples/device/usbtmc/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usbtmc_app.h"
 //--------------------------------------------------------------------+
@@ -57,14 +57,16 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
     led_blinking_task();
     usbtmc_app_task_iter();
   }
-
-  return 0;
 }
 
 //--------------------------------------------------------------------+
@@ -95,7 +97,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
diff --git a/examples/device/usbtmc/src/usb_descriptors.c b/examples/device/usbtmc/src/usb_descriptors.c
index ff682ff97..54948291e 100644
--- a/examples/device/usbtmc/src/usb_descriptors.c
+++ b/examples/device/usbtmc/src/usb_descriptors.c
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "class/usbtmc/usbtmc.h"
 #include "class/usbtmc/usbtmc_device.h"
@@ -188,55 +189,64 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
   "TinyUSB USBTMC",              // 4: USBTMC
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
-
   size_t chr_count;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }
-  else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
+
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
+
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) {
-      chr_count = 31;
-    }
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t)((((uint16_t)TUSB_DESC_STRING) << 8 ) | (2u*chr_count + 2u));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/usbtmc/src/usbtmc_app.c b/examples/device/usbtmc/src/usbtmc_app.c
index 8f87a6dca..fb25982c7 100644
--- a/examples/device/usbtmc/src/usbtmc_app.c
+++ b/examples/device/usbtmc/src/usbtmc_app.c
@@ -23,10 +23,10 @@
  *
  */
 
-#include <strings.h>
+#include <string.h>
 #include <stdlib.h>     /* atoi */
 #include "tusb.h"
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "main.h"
 
 #if (CFG_TUD_USBTMC_ENABLE_488)
@@ -88,14 +88,6 @@ static size_t buffer_tx_ix; // for transmitting using multiple transfers
 static uint8_t buffer[225]; // A few packets long should be enough.
 
 
-static usbtmc_msg_dev_dep_msg_in_header_t rspMsg = {
-    .bmTransferAttributes =
-    {
-      .EOM = 1,
-      .UsingTermChar = 0
-    }
-};
-
 void tud_usbtmc_open_cb(uint8_t interface_id)
 {
   (void)interface_id;
@@ -148,11 +140,14 @@ bool tud_usbtmc_msg_data_cb(void *data, size_t len, bool transfer_complete)
   queryState = transfer_complete;
   idnQuery = 0;
 
-  if(transfer_complete && (len >=4) && !strncasecmp("*idn?",data,4))
+  if ( transfer_complete && (len >= 4) &&
+       (!strncmp("*idn?", data, 4) || !strncmp("*IDN?", data, 4)) )
   {
     idnQuery = 1;
   }
-  if(transfer_complete && !strncasecmp("delay ",data,5))
+
+  if ( transfer_complete &&
+       (!strncmp("delay ", data, 5) || !strncmp("DELAY ", data, 5)) )
   {
     queryState = 0;
     int d = atoi((char*)data + 5);
@@ -184,9 +179,6 @@ static unsigned int msgReqLen;
 
 bool tud_usbtmc_msgBulkIn_request_cb(usbtmc_msg_request_dev_dep_in const * request)
 {
-  rspMsg.header.MsgID = request->header.MsgID,
-  rspMsg.header.bTag = request->header.bTag,
-  rspMsg.header.bTagInverse = request->header.bTagInverse;
   msgReqLen = request->TransferSize;
 
 #ifdef xDEBUG
@@ -250,7 +242,6 @@ void usbtmc_app_task_iter(void) {
     break;
   default:
     TU_ASSERT(false,);
-    return;
   }
 }
 
diff --git a/examples/device/usbtmc/visaQuery.py b/examples/device/usbtmc/visaQuery.py
index c4e5ad2b9..ca65daf97 100644
--- a/examples/device/usbtmc/visaQuery.py
+++ b/examples/device/usbtmc/visaQuery.py
@@ -36,8 +36,8 @@ def test_trig():
 	time.sleep(0.3) # SRQ may have some delay
 	assert (inst.read_stb() & 0x40), "SRQ not set after 0.3 seconds"
 	assert (inst.read_stb() == 0)
-	
-	
+
+
 def test_mav():
 	inst.write("delay 50")
 	inst.read_stb() # clear STB
@@ -45,15 +45,15 @@ def test_mav():
 	inst.write("123")
 	time.sleep(0.3)
 	assert (inst.read_stb() & 0x10), "MAV not set after 0.5 seconds"
-	
+
 	rsp = inst.read()
 	assert(rsp == "123\r\n")
-	
-	
+
+
 def test_srq():
 	assert (inst.read_stb() == 0)
 	inst.write("123")
-	
+
 	#inst.enable_event(pyvisa.constants.VI_EVENT_SERVICE_REQ, pyvisa.constants.VI_QUEUE)
 	#waitrsp = inst.wait_on_event(pyvisa.constants.VI_EVENT_SERVICE_REQ, 5000)
 	#inst.discard_events(pyvisa.constants.VI_EVENT_SERVICE_REQ, pyvisa.constants.VI_QUEUE)
@@ -64,7 +64,7 @@ def test_srq():
 	assert (stb == 0x50),msg
 
 	assert (inst.read_stb() == 0x10), "SRQ set at second read!"
-	
+
 	rsp = inst.read()
 	assert(rsp == "123\r\n")
 
@@ -110,7 +110,7 @@ def test_abort_in():
 	inst.timeout = 800
 	y = inst.read()
 	assert(y == "xxx\r\n")
-	
+
 def test_indicate():
 	# perform indicator pulse
 	usb_iface = inst.get_visa_attribute(pyvisa.constants.VI_ATTR_USB_INTFC_NUM)
@@ -120,8 +120,8 @@ def test_indicate():
 		assert(retv == b'\x01')
 	else:
 		assert((retv[1] == pyvisa.constants.StatusCode(0)) and (retv[0] == b'\x01')), f"indicator pulse failed: retv={retv}"
-	
-	
+
+
 def test_multi_read():
 	old_chunk_size = inst.chunk_size
 	longstr = "0123456789abcdefghijklmnopqrstuvwxyz" * 10
@@ -133,7 +133,7 @@ def test_multi_read():
 	y = inst.read()
 	assert (x + "\r\n" == y)
 	#inst.chunk_size = old_chunk_size
-	
+
 def test_stall_ep0():
 	usb_iface = inst.get_visa_attribute(pyvisa.constants.VI_ATTR_USB_INTFC_NUM)
 	inst.read_stb()
@@ -143,7 +143,7 @@ def test_stall_ep0():
 		assert(False)
 	except pyvisa.VisaIOError:
 		pass
-	
+
 	assert (inst.read_stb() == 0)
 
 
@@ -153,7 +153,7 @@ print(reslist)
 
 if (len(reslist) == 0):
     sys.exit()
-	
+
 inst = rm.open_resource(reslist[0]);
 inst.timeout = 3000
 
diff --git a/examples/device/video_capture/CMakeLists.txt b/examples/device/video_capture/CMakeLists.txt
index b92a2b804..80dc39ca5 100644
--- a/examples/device/video_capture/CMakeLists.txt
+++ b/examples/device/video_capture/CMakeLists.txt
@@ -1,15 +1,20 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 if (FORCE_READONLY)
@@ -29,6 +34,6 @@ target_include_directories(${PROJECT} PUBLIC
   ${CMAKE_CURRENT_SOURCE_DIR}/src
 )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/video_capture/Makefile b/examples/device/video_capture/Makefile
index fda66bcc1..d698a848d 100644
--- a/examples/device/video_capture/Makefile
+++ b/examples/device/video_capture/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 ifeq ($(DISABLE_MJPEG),1)
 CFLAGS += -DCFG_EXAMPLE_VIDEO_DISABLE_MJPEG
@@ -16,4 +15,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/video_capture/skip.txt b/examples/device/video_capture/skip.txt
index 5898664a2..db64cc639 100644
--- a/examples/device/video_capture/skip.txt
+++ b/examples/device/video_capture/skip.txt
@@ -1,3 +1,4 @@
 mcu:MSP430x5xx
 mcu:NUC121
 mcu:SAMD11
+family:espressif
diff --git a/examples/device/video_capture/src/CMakeLists.txt b/examples/device/video_capture/src/CMakeLists.txt
new file mode 100644
index 000000000..cef2b46ee
--- /dev/null
+++ b/examples/device/video_capture/src/CMakeLists.txt
@@ -0,0 +1,4 @@
+# This file is for ESP-IDF only
+idf_component_register(SRCS "main.c" "usb_descriptors.c"
+                    INCLUDE_DIRS "."
+                    REQUIRES boards tinyusb_src)
diff --git a/examples/device/video_capture/src/images.h b/examples/device/video_capture/src/images.h
index 0398428b3..ac372cb16 100644
--- a/examples/device/video_capture/src/images.h
+++ b/examples/device/video_capture/src/images.h
@@ -1,4 +1,5 @@
-#if defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPG)
+#if defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
+// uncopmressed frame
 static const unsigned char frame_buffer[128 * (96 + 1) * 2] = {
   /* 0 */
   0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80,
@@ -1650,8 +1651,10 @@ static const unsigned char frame_buffer[128 * (96 + 1) * 2] = {
   0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80,
   0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80,
 };
+
 #else
 
+// mpeg compressed data (not CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
 #define color_bar_0_jpg_len  511
 #define color_bar_1_jpg_len  512
 #define color_bar_2_jpg_len  511
diff --git a/examples/device/video_capture/src/main.c b/examples/device/video_capture/src/main.c
index 3ceebe821..2a2b0961f 100644
--- a/examples/device/video_capture/src/main.c
+++ b/examples/device/video_capture/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -40,7 +40,7 @@
  * - 1000 ms : device mounted
  * - 2500 ms : device is suspended
  */
-enum  {
+enum {
   BLINK_NOT_MOUNTED = 250,
   BLINK_MOUNTED = 1000,
   BLINK_SUSPENDED = 2500,
@@ -48,26 +48,38 @@ enum  {
 
 static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
 
-void led_blinking_task(void);
-void video_task(void);
+void led_blinking_task(void* param);
+void usb_device_task(void *param);
+void video_task(void* param);
 
-/*------------- MAIN -------------*/
-int main(void)
-{
+#if CFG_TUSB_OS == OPT_OS_FREERTOS
+void freertos_init_task(void);
+#endif
+
+
+//--------------------------------------------------------------------+
+// Main
+//--------------------------------------------------------------------+
+int main(void) {
   board_init();
 
+  // If using FreeRTOS: create blinky, tinyusb device, video task
+#if CFG_TUSB_OS == OPT_OS_FREERTOS
+  freertos_init_task();
+#else
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
-  while (1)
-  {
-    tud_task(); // tinyusb device task
-    led_blinking_task();
-
-    video_task();
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
   }
 
-  return 0;
+  while (1) {
+    tud_task(); // tinyusb device task
+    led_blinking_task(NULL);
+    video_task(NULL);
+  }
+#endif
 }
 
 //--------------------------------------------------------------------+
@@ -75,33 +87,28 @@ int main(void)
 //--------------------------------------------------------------------+
 
 // Invoked when device is mounted
-void tud_mount_cb(void)
-{
+void tud_mount_cb(void) {
   blink_interval_ms = BLINK_MOUNTED;
 }
 
 // Invoked when device is unmounted
-void tud_umount_cb(void)
-{
+void tud_umount_cb(void) {
   blink_interval_ms = BLINK_NOT_MOUNTED;
 }
 
 // Invoked when usb bus is suspended
 // remote_wakeup_en : if host allow us  to perform remote wakeup
 // Within 7ms, device must draw an average of current less than 2.5 mA from bus
-void tud_suspend_cb(bool remote_wakeup_en)
-{
+void tud_suspend_cb(bool remote_wakeup_en) {
   (void) remote_wakeup_en;
   blink_interval_ms = BLINK_SUSPENDED;
 }
 
 // Invoked when usb bus is resumed
-void tud_resume_cb(void)
-{
-  blink_interval_ms = BLINK_MOUNTED;
+void tud_resume_cb(void) {
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
-
 //--------------------------------------------------------------------+
 // USB Video
 //--------------------------------------------------------------------+
@@ -109,11 +116,12 @@ static unsigned frame_num = 0;
 static unsigned tx_busy = 0;
 static unsigned interval_ms = 1000 / FRAME_RATE;
 
-/* YUY2 frame buffer */
 #ifdef CFG_EXAMPLE_VIDEO_READONLY
+// For mcus that does not have enough SRAM for frame buffer, we use fixed frame data.
+// To further reduce the size, we use MJPEG format instead of YUY2.
 #include "images.h"
 
-# if !defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPG)
+#if !defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
 static struct {
   uint32_t       size;
   uint8_t const *buffer;
@@ -127,29 +135,30 @@ static struct {
   {color_bar_6_jpg_len, color_bar_6_jpg},
   {color_bar_7_jpg_len, color_bar_7_jpg},
 };
-# endif
+#endif
 
 #else
+
+// YUY2 frame buffer
 static uint8_t frame_buffer[FRAME_WIDTH * FRAME_HEIGHT * 16 / 8];
-static void fill_color_bar(uint8_t *buffer, unsigned start_position)
-{
-  /* EBU color bars
-   * See also https://stackoverflow.com/questions/6939422 */
+
+static void fill_color_bar(uint8_t* buffer, unsigned start_position) {
+  /* EBU color bars: https://stackoverflow.com/questions/6939422 */
   static uint8_t const bar_color[8][4] = {
-    /*  Y,   U,   Y,   V */
-    { 235, 128, 235, 128}, /* 100% White */
-    { 219,  16, 219, 138}, /* Yellow */
-    { 188, 154, 188,  16}, /* Cyan */
-    { 173,  42, 173,  26}, /* Green */
-    {  78, 214,  78, 230}, /* Magenta */
-    {  63, 102,  63, 240}, /* Red */
-    {  32, 240,  32, 118}, /* Blue */
-    {  16, 128,  16, 128}, /* Black */
+      /*  Y,   U,   Y,   V */
+      { 235, 128, 235, 128}, /* 100% White */
+      { 219,  16, 219, 138}, /* Yellow */
+      { 188, 154, 188,  16}, /* Cyan */
+      { 173,  42, 173,  26}, /* Green */
+      {  78, 214,  78, 230}, /* Magenta */
+      {  63, 102,  63, 240}, /* Red */
+      {  32, 240,  32, 118}, /* Blue */
+      {  16, 128,  16, 128}, /* Black */
   };
-  uint8_t *p;
+  uint8_t* p;
 
   /* Generate the 1st line */
-  uint8_t *end = &buffer[FRAME_WIDTH * 2];
+  uint8_t* end = &buffer[FRAME_WIDTH * 2];
   unsigned idx = (FRAME_WIDTH / 2 - 1) - (start_position % (FRAME_WIDTH / 2));
   p = &buffer[idx * 4];
   for (unsigned i = 0; i < 8; ++i) {
@@ -161,6 +170,7 @@ static void fill_color_bar(uint8_t *buffer, unsigned start_position)
       }
     }
   }
+
   /* Duplicate the 1st line to the others */
   p = &buffer[FRAME_WIDTH * 2];
   for (unsigned i = 1; i < FRAME_HEIGHT; ++i) {
@@ -168,32 +178,33 @@ static void fill_color_bar(uint8_t *buffer, unsigned start_position)
     p += FRAME_WIDTH * 2;
   }
 }
+
 #endif
 
-void video_task(void)
-{
+void video_send_frame(void) {
   static unsigned start_ms = 0;
   static unsigned already_sent = 0;
 
   if (!tud_video_n_streaming(0, 0)) {
-    already_sent  = 0;
-    frame_num     = 0;
+    already_sent = 0;
+    frame_num = 0;
     return;
   }
 
   if (!already_sent) {
     already_sent = 1;
+    tx_busy = 1;
     start_ms = board_millis();
 #ifdef CFG_EXAMPLE_VIDEO_READONLY
-# if defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPG)
+    #if defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
     tud_video_n_frame_xfer(0, 0, (void*)(uintptr_t)&frame_buffer[(frame_num % (FRAME_WIDTH / 2)) * 4],
                            FRAME_WIDTH * FRAME_HEIGHT * 16/8);
-# else
+    #else
     tud_video_n_frame_xfer(0, 0, (void*)(uintptr_t)frames[frame_num % 8].buffer, frames[frame_num % 8].size);
-# endif
+    #endif
 #else
     fill_color_bar(frame_buffer, frame_num);
-    tud_video_n_frame_xfer(0, 0, (void*)frame_buffer, FRAME_WIDTH * FRAME_HEIGHT * 16/8);
+    tud_video_n_frame_xfer(0, 0, (void*) frame_buffer, FRAME_WIDTH * FRAME_HEIGHT * 16 / 8);
 #endif
   }
 
@@ -201,49 +212,140 @@ void video_task(void)
   if (cur - start_ms < interval_ms) return; // not enough time
   if (tx_busy) return;
   start_ms += interval_ms;
+  tx_busy = 1;
 
 #ifdef CFG_EXAMPLE_VIDEO_READONLY
-# if defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPG)
+  #if defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
   tud_video_n_frame_xfer(0, 0, (void*)(uintptr_t)&frame_buffer[(frame_num % (FRAME_WIDTH / 2)) * 4],
                          FRAME_WIDTH * FRAME_HEIGHT * 16/8);
-# else
+  #else
   tud_video_n_frame_xfer(0, 0, (void*)(uintptr_t)frames[frame_num % 8].buffer, frames[frame_num % 8].size);
-# endif
+  #endif
 #else
   fill_color_bar(frame_buffer, frame_num);
-  tud_video_n_frame_xfer(0, 0, (void*)frame_buffer, FRAME_WIDTH * FRAME_HEIGHT * 16/8);
+  tud_video_n_frame_xfer(0, 0, (void*) frame_buffer, FRAME_WIDTH * FRAME_HEIGHT * 16 / 8);
 #endif
 }
 
-void tud_video_frame_xfer_complete_cb(uint_fast8_t ctl_idx, uint_fast8_t stm_idx)
-{
-  (void)ctl_idx; (void)stm_idx;
+
+void video_task(void* param) {
+  (void) param;
+
+  while(1) {
+    video_send_frame();
+
+    #if CFG_TUSB_OS == OPT_OS_FREERTOS
+    vTaskDelay(interval_ms / portTICK_PERIOD_MS);
+    #else
+    return;
+    #endif
+  }
+}
+
+void tud_video_frame_xfer_complete_cb(uint_fast8_t ctl_idx, uint_fast8_t stm_idx) {
+  (void) ctl_idx;
+  (void) stm_idx;
   tx_busy = 0;
   /* flip buffer */
   ++frame_num;
 }
 
 int tud_video_commit_cb(uint_fast8_t ctl_idx, uint_fast8_t stm_idx,
-			video_probe_and_commit_control_t const *parameters)
-{
-  (void)ctl_idx; (void)stm_idx;
+                        video_probe_and_commit_control_t const* parameters) {
+  (void) ctl_idx;
+  (void) stm_idx;
   /* convert unit to ms from 100 ns */
   interval_ms = parameters->dwFrameInterval / 10000;
   return VIDEO_ERROR_NONE;
 }
 
 //--------------------------------------------------------------------+
-// BLINKING TASK
+// Blinking Task
 //--------------------------------------------------------------------+
-void led_blinking_task(void)
-{
+void led_blinking_task(void* param) {
+  (void) param;
   static uint32_t start_ms = 0;
   static bool led_state = false;
 
-  // Blink every interval ms
-  if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
-  start_ms += blink_interval_ms;
+  while (1) {
+    #if CFG_TUSB_OS == OPT_OS_FREERTOS
+    vTaskDelay(blink_interval_ms / portTICK_PERIOD_MS);
+    #else
+    if (board_millis() - start_ms < blink_interval_ms) return; // not enough time
+    #endif
 
-  board_led_write(led_state);
-  led_state = 1 - led_state; // toggle
+    start_ms += blink_interval_ms;
+    board_led_write(led_state);
+    led_state = 1 - led_state; // toggle
+  }
 }
+
+//--------------------------------------------------------------------+
+// FreeRTOS
+//--------------------------------------------------------------------+
+#if CFG_TUSB_OS == OPT_OS_FREERTOS
+
+#define BLINKY_STACK_SIZE   configMINIMAL_STACK_SIZE
+#define VIDEO_STACK_SIZE    (configMINIMAL_STACK_SIZE*4)
+
+#if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
+  #define USBD_STACK_SIZE     4096
+  int main(void);
+  void app_main(void) {
+    main();
+  }
+#else
+  // Increase stack size when debug log is enabled
+  #define USBD_STACK_SIZE    (3*configMINIMAL_STACK_SIZE/2) * (CFG_TUSB_DEBUG ? 2 : 1)
+#endif
+
+// static task
+#if configSUPPORT_STATIC_ALLOCATION
+StackType_t blinky_stack[BLINKY_STACK_SIZE];
+StaticTask_t blinky_taskdef;
+
+StackType_t  usb_device_stack[USBD_STACK_SIZE];
+StaticTask_t usb_device_taskdef;
+
+StackType_t  video_stack[VIDEO_STACK_SIZE];
+StaticTask_t video_taskdef;
+#endif
+
+// USB Device Driver task
+// This top level thread process all usb events and invoke callbacks
+void usb_device_task(void *param) {
+  (void) param;
+
+  // init device stack on configured roothub port
+  // This should be called after scheduler/kernel is started.
+  // Otherwise, it could cause kernel issue since USB IRQ handler does use RTOS queue API.
+  tud_init(BOARD_TUD_RHPORT);
+
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
+  // RTOS forever loop
+  while (1) {
+    // put this thread to waiting state until there is new events
+    tud_task();
+  }
+}
+
+void freertos_init_task(void) {
+  #if configSUPPORT_STATIC_ALLOCATION
+  xTaskCreateStatic(led_blinking_task, "blinky", BLINKY_STACK_SIZE, NULL, 1, blinky_stack, &blinky_taskdef);
+  xTaskCreateStatic(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);
+  xTaskCreateStatic(video_task, "cdc", VIDEO_STACK_SIZE, NULL, configMAX_PRIORITIES - 2, video_stack, &video_taskdef);
+  #else
+  xTaskCreate(led_blinking_task, "blinky", BLINKY_STACK_SIZE, NULL, 1, NULL);
+  xTaskCreate(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, NULL);
+  xTaskCreate(video_task, "video", VIDEO_STACK_SZIE, NULL, configMAX_PRIORITIES - 2, NULL);
+  #endif
+
+  // skip starting scheduler (and return) for ESP32-S2 or ESP32-S3
+  #if !TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
+  vTaskStartScheduler();
+  #endif
+}
+#endif
diff --git a/examples/device/video_capture/src/tusb_config.h b/examples/device/video_capture/src/tusb_config.h
index e567ba669..bdfc37d87 100644
--- a/examples/device/video_capture/src/tusb_config.h
+++ b/examples/device/video_capture/src/tusb_config.h
@@ -57,6 +57,11 @@
 #define CFG_TUSB_OS           OPT_OS_NONE
 #endif
 
+// Espressif IDF requires "freertos/" prefix in include path
+#if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
+#define CFG_TUSB_OS_INC_PATH  freertos/
+#endif
+
 #ifndef CFG_TUSB_DEBUG
 #define CFG_TUSB_DEBUG        0
 #endif
@@ -97,9 +102,15 @@
 // The number of video streaming interfaces
 #define CFG_TUD_VIDEO_STREAMING  1
 
-// video streaming endpoint size
+// video streaming endpoint buffer size
 #define CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE  256
 
+// use bulk endpoint for streaming interface
+#define CFG_TUD_VIDEO_STREAMING_BULK 1
+
+//#define CFG_EXAMPLE_VIDEO_READONLY
+//#define CFG_EXAMPLE_VIDEO_DISABLE_MJPEG
+
 #ifdef __cplusplus
  }
 #endif
diff --git a/examples/device/video_capture/src/usb_descriptors.c b/examples/device/video_capture/src/usb_descriptors.c
index 499ee311c..f308c75a7 100644
--- a/examples/device/video_capture/src/usb_descriptors.c
+++ b/examples/device/video_capture/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -36,14 +37,36 @@
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
     _PID_MAP(MIDI, 3) | _PID_MAP(AUDIO, 4) | _PID_MAP(VIDEO, 5) | _PID_MAP(VENDOR, 6) )
 
+#define USB_VID   0xCafe
+#define USB_BCD   0x0200
+
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+  STRID_UVC_CONTROL,
+  STRID_UVC_STREAMING,
+};
+
+// array of pointer to string descriptors
+char const* string_desc_arr[] = {
+    (const char[]) {0x09, 0x04}, // 0: is supported language is English (0x0409)
+    "TinyUSB",                     // 1: Manufacturer
+    "TinyUSB Device",              // 2: Product
+    NULL,                          // 3: Serials will use unique ID if possible
+    "TinyUSB UVC Control",         // 4: UVC Interface
+    "TinyUSB UVC Streaming",       // 5: UVC Interface
+};
+
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
-tusb_desc_device_t const desc_device =
-{
+tusb_desc_device_t const desc_device = {
     .bLength            = sizeof(tusb_desc_device_t),
     .bDescriptorType    = TUSB_DESC_DEVICE,
-    .bcdUSB             = 0x0200,
+    .bcdUSB             = USB_BCD,
 
     // Use Interface Association Descriptor (IAD) for Video
     // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
@@ -53,124 +76,409 @@ tusb_desc_device_t const desc_device =
 
     .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
-    .idVendor           = 0xCafe,
+    .idVendor           = USB_VID,
     .idProduct          = USB_PID,
     .bcdDevice          = 0x0100,
 
-    .iManufacturer      = 0x01,
-    .iProduct           = 0x02,
-    .iSerialNumber      = 0x03,
+    .iManufacturer      = STRID_MANUFACTURER,
+    .iProduct           = STRID_PRODUCT,
+    .iSerialNumber      = STRID_SERIAL,
 
     .bNumConfigurations = 0x01
 };
 
 // Invoked when received GET DEVICE DESCRIPTOR
 // Application return pointer to descriptor
-uint8_t const * tud_descriptor_device_cb(void)
-{
-  return (uint8_t const *) &desc_device;
+uint8_t const* tud_descriptor_device_cb(void) {
+  return (uint8_t const*) &desc_device;
 }
 
 //--------------------------------------------------------------------+
 // Configuration Descriptor
 //--------------------------------------------------------------------+
 
-#if defined(CFG_EXAMPLE_VIDEO_READONLY) && !defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
-#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_VIDEO_CAPTURE_DESC_MJPEG_LEN)
-#else
-#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_VIDEO_CAPTURE_DESC_UNCOMPR_LEN)
-#endif
+/* Time stamp base clock. It is a deprecated parameter. */
+#define UVC_CLOCK_FREQUENCY    27000000
 
+/* video capture path */
+#define UVC_ENTITY_CAP_INPUT_TERMINAL  0x01
+#define UVC_ENTITY_CAP_OUTPUT_TERMINAL 0x02
+
+enum {
+  ITF_NUM_VIDEO_CONTROL,
+  ITF_NUM_VIDEO_STREAMING,
+  ITF_NUM_TOTAL
+};
+
+// Select appropriate endpoint number
 #if TU_CHECK_MCU(OPT_MCU_LPC175X_6X, OPT_MCU_LPC177X_8X, OPT_MCU_LPC40XX)
   // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
   // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In, 5 Bulk etc ...
-  #define EPNUM_VIDEO_IN    0x83
-
+  #define EPNUM_VIDEO_IN    (CFG_TUD_VIDEO_STREAMING_BULK ? 0x82 : 0x83)
 #elif TU_CHECK_MCU(OPT_MCU_NRF5X)
   // nRF5x ISO can only be endpoint 8
-  #define EPNUM_VIDEO_IN    0x88
-
+  #define EPNUM_VIDEO_IN    (CFG_TUD_VIDEO_STREAMING_BULK ? 0x81 : 0x88)
 #else
   #define EPNUM_VIDEO_IN    0x81
-
 #endif
 
-uint8_t const desc_fs_configuration[] =
-{
-  // Config number, interface count, string index, total length, attribute, power in mA
-  TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0, 500),
-  // IAD for Video Control
 #if defined(CFG_EXAMPLE_VIDEO_READONLY) && !defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
-  TUD_VIDEO_CAPTURE_DESCRIPTOR_MJPEG(4, EPNUM_VIDEO_IN,
-                                     FRAME_WIDTH, FRAME_HEIGHT, FRAME_RATE,
-                                     CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE)
+  #define USE_MJPEG 1
+#else
+  #define USE_MJPEG 0
+#endif
+
+#define USE_ISO_STREAMING (!CFG_TUD_VIDEO_STREAMING_BULK)
+
+typedef struct TU_ATTR_PACKED {
+  tusb_desc_interface_t itf;
+  tusb_desc_video_control_header_1itf_t header;
+  tusb_desc_video_control_camera_terminal_t camera_terminal;
+  tusb_desc_video_control_output_terminal_t output_terminal;
+} uvc_control_desc_t;
+
+/* Windows support YUY2 and NV12
+ * https://docs.microsoft.com/en-us/windows-hardware/drivers/stream/usb-video-class-driver-overview */
+
+typedef struct TU_ATTR_PACKED {
+  tusb_desc_interface_t itf;
+  tusb_desc_video_streaming_input_header_1byte_t header;
+
+#if USE_MJPEG
+  tusb_desc_video_format_mjpeg_t format;
+  tusb_desc_video_frame_mjpeg_continuous_t frame;
+#else
+  tusb_desc_video_format_uncompressed_t format;
+  tusb_desc_video_frame_uncompressed_continuous_t frame;
+#endif
+
+  tusb_desc_video_streaming_color_matching_t color;
+
+#if USE_ISO_STREAMING
+  // For ISO streaming, USB spec requires to alternate interface
+  tusb_desc_interface_t itf_alt;
+#endif
+
+  tusb_desc_endpoint_t ep;
+} uvc_streaming_desc_t;
+
+typedef struct TU_ATTR_PACKED {
+  tusb_desc_configuration_t config;
+  tusb_desc_interface_assoc_t iad;
+  uvc_control_desc_t video_control;
+  uvc_streaming_desc_t video_streaming;
+} uvc_cfg_desc_t;
+
+const uvc_cfg_desc_t desc_fs_configuration = {
+    .config = {
+        .bLength = sizeof(tusb_desc_configuration_t),
+        .bDescriptorType = TUSB_DESC_CONFIGURATION,
+
+        .wTotalLength = sizeof(uvc_cfg_desc_t),
+        .bNumInterfaces = ITF_NUM_TOTAL,
+        .bConfigurationValue = 1,
+        .iConfiguration = 0,
+        .bmAttributes =  TU_BIT(7),
+        .bMaxPower = 100 / 2
+    },
+    .iad = {
+        .bLength = sizeof(tusb_desc_interface_assoc_t),
+        .bDescriptorType = TUSB_DESC_INTERFACE_ASSOCIATION,
+
+        .bFirstInterface = ITF_NUM_VIDEO_CONTROL,
+        .bInterfaceCount = 2,
+        .bFunctionClass = TUSB_CLASS_VIDEO,
+        .bFunctionSubClass = VIDEO_SUBCLASS_INTERFACE_COLLECTION,
+        .bFunctionProtocol = VIDEO_ITF_PROTOCOL_UNDEFINED,
+        .iFunction = 0
+    },
+
+    .video_control = {
+        .itf = {
+            .bLength = sizeof(tusb_desc_interface_t),
+            .bDescriptorType = TUSB_DESC_INTERFACE,
+
+            .bInterfaceNumber = ITF_NUM_VIDEO_CONTROL,
+            .bAlternateSetting = 0,
+            .bNumEndpoints = 0,
+            .bInterfaceClass = TUSB_CLASS_VIDEO,
+            .bInterfaceSubClass = VIDEO_SUBCLASS_CONTROL,
+            .bInterfaceProtocol = VIDEO_ITF_PROTOCOL_15,
+            .iInterface = STRID_UVC_CONTROL
+        },
+        .header = {
+            .bLength = sizeof(tusb_desc_video_control_header_1itf_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VC_HEADER,
+
+            .bcdUVC = VIDEO_BCD_1_50,
+            .wTotalLength = sizeof(uvc_control_desc_t) - sizeof(tusb_desc_interface_t), // CS VC descriptors only
+            .dwClockFrequency = UVC_CLOCK_FREQUENCY,
+            .bInCollection = 1,
+            .baInterfaceNr = { ITF_NUM_VIDEO_STREAMING }
+        },
+        .camera_terminal = {
+            .bLength = sizeof(tusb_desc_video_control_camera_terminal_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VC_INPUT_TERMINAL,
+
+            .bTerminalID = UVC_ENTITY_CAP_INPUT_TERMINAL,
+            .wTerminalType = VIDEO_ITT_CAMERA,
+            .bAssocTerminal = 0,
+            .iTerminal = 0,
+            .wObjectiveFocalLengthMin = 0,
+            .wObjectiveFocalLengthMax = 0,
+            .wOcularFocalLength = 0,
+            .bControlSize = 3,
+            .bmControls = { 0, 0, 0 }
+        },
+        .output_terminal = {
+            .bLength = sizeof(tusb_desc_video_control_output_terminal_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VC_OUTPUT_TERMINAL,
+
+            .bTerminalID = UVC_ENTITY_CAP_OUTPUT_TERMINAL,
+            .wTerminalType = VIDEO_TT_STREAMING,
+            .bAssocTerminal = 0,
+            .bSourceID = UVC_ENTITY_CAP_INPUT_TERMINAL,
+            .iTerminal = 0
+        }
+    },
+
+    .video_streaming = {
+        .itf = {
+            .bLength = sizeof(tusb_desc_interface_t),
+            .bDescriptorType = TUSB_DESC_INTERFACE,
+
+            .bInterfaceNumber = ITF_NUM_VIDEO_STREAMING,
+            .bAlternateSetting = 0,
+            .bNumEndpoints = CFG_TUD_VIDEO_STREAMING_BULK, // bulk 1, iso 0
+            .bInterfaceClass = TUSB_CLASS_VIDEO,
+            .bInterfaceSubClass = VIDEO_SUBCLASS_STREAMING,
+            .bInterfaceProtocol = VIDEO_ITF_PROTOCOL_15,
+            .iInterface = STRID_UVC_STREAMING
+        },
+        .header = {
+            .bLength = sizeof(tusb_desc_video_streaming_input_header_1byte_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VS_INPUT_HEADER,
+
+            .bNumFormats = 1,
+            .wTotalLength = sizeof(uvc_streaming_desc_t) - sizeof(tusb_desc_interface_t)
+                - sizeof(tusb_desc_endpoint_t) - (USE_ISO_STREAMING ? sizeof(tusb_desc_interface_t) : 0) , // CS VS descriptors only
+            .bEndpointAddress = EPNUM_VIDEO_IN,
+            .bmInfo = 0,
+            .bTerminalLink = UVC_ENTITY_CAP_OUTPUT_TERMINAL,
+            .bStillCaptureMethod = 0,
+            .bTriggerSupport = 0,
+            .bTriggerUsage = 0,
+            .bControlSize = 1,
+            .bmaControls = { 0 }
+        },
+        .format = {
+#if USE_MJPEG
+            .bLength = sizeof(tusb_desc_video_format_mjpeg_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VS_FORMAT_MJPEG,
+            .bFormatIndex = 1, // 1-based index
+            .bNumFrameDescriptors = 1,
+            .bmFlags = 0,
+#else
+            .bLength = sizeof(tusb_desc_video_format_uncompressed_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VS_FORMAT_UNCOMPRESSED,
+            .bFormatIndex = 1, // 1-based index
+            .bNumFrameDescriptors = 1,
+            .guidFormat = { TUD_VIDEO_GUID_YUY2 },
+            .bBitsPerPixel = 16,
+#endif
+            .bDefaultFrameIndex = 1,
+            .bAspectRatioX = 0,
+            .bAspectRatioY = 0,
+            .bmInterlaceFlags = 0,
+            .bCopyProtect = 0
+        },
+        .frame = {
+#if USE_MJPEG
+            .bLength = sizeof(tusb_desc_video_frame_mjpeg_continuous_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VS_FRAME_MJPEG,
 #else
-  TUD_VIDEO_CAPTURE_DESCRIPTOR_UNCOMPR(4, EPNUM_VIDEO_IN,
-                                       FRAME_WIDTH, FRAME_HEIGHT, FRAME_RATE,
-                                       CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE)
+            .bLength = sizeof(tusb_desc_video_frame_uncompressed_continuous_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VS_FRAME_UNCOMPRESSED,
 #endif
+            .bFrameIndex = 1, // 1-based index
+            .bmCapabilities = 0,
+            .wWidth = FRAME_WIDTH,
+            .wHeight = FRAME_HEIGHT,
+            .dwMinBitRate = FRAME_WIDTH * FRAME_HEIGHT * 16 * 1,
+            .dwMaxBitRate = FRAME_WIDTH * FRAME_HEIGHT * 16 * FRAME_RATE,
+            .dwMaxVideoFrameBufferSize = FRAME_WIDTH * FRAME_HEIGHT * 16 / 8,
+            .dwDefaultFrameInterval = 10000000 / FRAME_RATE,
+            .bFrameIntervalType = 0, // continuous
+            .dwFrameInterval = {
+                10000000 / FRAME_RATE, // min
+                10000000, // max
+                10000000 / FRAME_RATE // step
+            }
+        },
+        .color = {
+            .bLength = sizeof(tusb_desc_video_streaming_color_matching_t),
+            .bDescriptorType = TUSB_DESC_CS_INTERFACE,
+            .bDescriptorSubType = VIDEO_CS_ITF_VS_COLORFORMAT,
+
+            .bColorPrimaries = VIDEO_COLOR_PRIMARIES_BT709,
+            .bTransferCharacteristics = VIDEO_COLOR_XFER_CH_BT709,
+            .bMatrixCoefficients = VIDEO_COLOR_COEF_SMPTE170M
+        },
+
+#if USE_ISO_STREAMING
+        .itf_alt = {
+            .bLength = sizeof(tusb_desc_interface_t),
+            .bDescriptorType = TUSB_DESC_INTERFACE,
+
+            .bInterfaceNumber = ITF_NUM_VIDEO_STREAMING,
+            .bAlternateSetting = 1,
+            .bNumEndpoints = 1,
+            .bInterfaceClass = TUSB_CLASS_VIDEO,
+            .bInterfaceSubClass = VIDEO_SUBCLASS_STREAMING,
+            .bInterfaceProtocol = VIDEO_ITF_PROTOCOL_15,
+            .iInterface = STRID_UVC_STREAMING
+        },
+#endif
+
+        .ep = {
+            .bLength = sizeof(tusb_desc_endpoint_t),
+            .bDescriptorType = TUSB_DESC_ENDPOINT,
+
+            .bEndpointAddress = EPNUM_VIDEO_IN,
+            .bmAttributes = {
+                .xfer = CFG_TUD_VIDEO_STREAMING_BULK ? TUSB_XFER_BULK : TUSB_XFER_ISOCHRONOUS,
+                .sync = CFG_TUD_VIDEO_STREAMING_BULK ? 0 : 1 // asynchronous
+            },
+            .wMaxPacketSize = CFG_TUD_VIDEO_STREAMING_BULK ? 64 : CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE,
+            .bInterval = 1
+        }
+    }
 };
 
+#if TUD_OPT_HIGH_SPEED
+uvc_cfg_desc_t desc_hs_configuration;
+
+static uint8_t * get_hs_configuration_desc(void) {
+  static bool init = false;
+
+  if (!init) {
+    desc_hs_configuration = desc_fs_configuration;
+    // change endpoint bulk size to 512 if bulk streaming
+    if (CFG_TUD_VIDEO_STREAMING_BULK) {
+      desc_hs_configuration.video_streaming.ep.wMaxPacketSize = 512;
+    }
+  }
+  init = true;
+
+  return (uint8_t *) &desc_hs_configuration;
+}
+
+// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier = {
+    .bLength            = sizeof(tusb_desc_device_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bcdUSB             = USB_BCD,
+
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+
+    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+    .bNumConfigurations = 0x01,
+    .bReserved          = 0x00
+};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
+uint8_t const* tud_descriptor_device_qualifier_cb(void) {
+  return (uint8_t const*) &desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index) {
+  (void) index; // for multiple configurations
+  // if link speed is high return fullspeed config, and vice versa
+  if (tud_speed_get() == TUSB_SPEED_HIGH) {
+    return (uint8_t const*) &desc_fs_configuration;
+  } else {
+    return get_hs_configuration_desc();
+  }
+}
+#endif // highspeed
+
 // Invoked when received GET CONFIGURATION DESCRIPTOR
 // Application return pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete
-uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
-{
+uint8_t const* tud_descriptor_configuration_cb(uint8_t index) {
   (void) index; // for multiple configurations
 
-  return desc_fs_configuration;
+#if TUD_OPT_HIGH_SPEED
+  // Although we are highspeed, host may be fullspeed.
+  if (tud_speed_get() == TUSB_SPEED_HIGH) {
+    return get_hs_configuration_desc();
+  } else
+#endif
+  {
+    return (uint8_t const*) &desc_fs_configuration;
+  }
 }
 
 //--------------------------------------------------------------------+
 // String Descriptors
 //--------------------------------------------------------------------+
 
-// array of pointer to string descriptors
-char const* string_desc_arr [] =
-{
-  (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
-  "TinyUSB",                     // 1: Manufacturer
-  "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
-  "TinyUSB UVC",                 // 4: UVC Interface
-};
-
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
 
-  uint8_t chr_count;
+  switch (index) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    const char* str = string_desc_arr[index];
+      if (index >= sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) return NULL;
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      const char* str = string_desc_arr[index];
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if (chr_count > max_count) chr_count = max_count;
+
+      // Convert ASCII string into UTF-16
+      for (size_t i = 0; i < chr_count; i++) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/video_capture/src/usb_descriptors.h b/examples/device/video_capture/src/usb_descriptors.h
index f1ed3c8e9..12d41b2f3 100644
--- a/examples/device/video_capture/src/usb_descriptors.h
+++ b/examples/device/video_capture/src/usb_descriptors.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Jerzy Kasenbreg
@@ -27,21 +27,11 @@
 #ifndef _USB_DESCRIPTORS_H_
 #define _USB_DESCRIPTORS_H_
 
-/* Time stamp base clock. It is a deprecated parameter. */
-#define UVC_CLOCK_FREQUENCY    27000000
-/* video capture path */
-#define UVC_ENTITY_CAP_INPUT_TERMINAL  0x01
-#define UVC_ENTITY_CAP_OUTPUT_TERMINAL 0x02
-
 #define FRAME_WIDTH   128
 #define FRAME_HEIGHT  96
 #define FRAME_RATE    10
 
-enum {
-  ITF_NUM_VIDEO_CONTROL,
-  ITF_NUM_VIDEO_STREAMING,
-  ITF_NUM_TOTAL
-};
+// NOTE: descriptor template is not used but leave here as reference
 
 #define TUD_VIDEO_CAPTURE_DESC_UNCOMPR_LEN (\
     TUD_VIDEO_DESC_IAD_LEN\
@@ -79,6 +69,38 @@ enum {
     + 7/* Endpoint */\
   )
 
+#define TUD_VIDEO_CAPTURE_DESC_UNCOMPR_BULK_LEN (\
+    TUD_VIDEO_DESC_IAD_LEN\
+    /* control */\
+    + TUD_VIDEO_DESC_STD_VC_LEN\
+    + (TUD_VIDEO_DESC_CS_VC_LEN + 1/*bInCollection*/)\
+    + TUD_VIDEO_DESC_CAMERA_TERM_LEN\
+    + TUD_VIDEO_DESC_OUTPUT_TERM_LEN\
+    /* Interface 1, Alternate 0 */\
+    + TUD_VIDEO_DESC_STD_VS_LEN\
+    + (TUD_VIDEO_DESC_CS_VS_IN_LEN + 1/*bNumFormats x bControlSize*/)\
+    + TUD_VIDEO_DESC_CS_VS_FMT_UNCOMPR_LEN\
+    + TUD_VIDEO_DESC_CS_VS_FRM_UNCOMPR_CONT_LEN\
+    + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN\
+    + 7/* Endpoint */\
+  )
+
+#define TUD_VIDEO_CAPTURE_DESC_MJPEG_BULK_LEN (\
+    TUD_VIDEO_DESC_IAD_LEN\
+    /* control */\
+    + TUD_VIDEO_DESC_STD_VC_LEN\
+    + (TUD_VIDEO_DESC_CS_VC_LEN + 1/*bInCollection*/)\
+    + TUD_VIDEO_DESC_CAMERA_TERM_LEN\
+    + TUD_VIDEO_DESC_OUTPUT_TERM_LEN\
+    /* Interface 1, Alternate 0 */\
+    + TUD_VIDEO_DESC_STD_VS_LEN\
+    + (TUD_VIDEO_DESC_CS_VS_IN_LEN + 1/*bNumFormats x bControlSize*/)\
+    + TUD_VIDEO_DESC_CS_VS_FMT_MJPEG_LEN\
+    + TUD_VIDEO_DESC_CS_VS_FRM_MJPEG_CONT_LEN\
+    + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN\
+    + 7/* Endpoint */\
+  )
+
 /* Windows support YUY2 and NV12
  * https://docs.microsoft.com/en-us/windows-hardware/drivers/stream/usb-video-class-driver-overview */
 
@@ -94,23 +116,17 @@ enum {
 #define TUD_VIDEO_CAPTURE_DESCRIPTOR_UNCOMPR(_stridx, _epin, _width, _height, _fps, _epsize) \
   TUD_VIDEO_DESC_IAD(ITF_NUM_VIDEO_CONTROL, /* 2 Interfaces */ 0x02, _stridx), \
   /* Video control 0 */ \
-  TUD_VIDEO_DESC_STD_VC(ITF_NUM_VIDEO_CONTROL, 0, _stridx), \
-    TUD_VIDEO_DESC_CS_VC( /* UVC 1.5*/ 0x0150, \
-         /* wTotalLength - bLength */ \
-         TUD_VIDEO_DESC_CAMERA_TERM_LEN + TUD_VIDEO_DESC_OUTPUT_TERM_LEN, \
-         UVC_CLOCK_FREQUENCY, ITF_NUM_VIDEO_STREAMING), \
-      TUD_VIDEO_DESC_CAMERA_TERM(UVC_ENTITY_CAP_INPUT_TERMINAL, 0, 0,\
-                                 /*wObjectiveFocalLengthMin*/0, /*wObjectiveFocalLengthMax*/0,\
-                                 /*wObjectiveFocalLength*/0, /*bmControls*/0), \
+  TUD_VIDEO_DESC_STD_VC(ITF_NUM_VIDEO_CONTROL, 0, _stridx),                                  \
+    /* Header: UVC 1.5, length of followed descs, clock (deprecated), streaming interfaces */ \
+    TUD_VIDEO_DESC_CS_VC(0x0150, TUD_VIDEO_DESC_CAMERA_TERM_LEN + TUD_VIDEO_DESC_OUTPUT_TERM_LEN, UVC_CLOCK_FREQUENCY, ITF_NUM_VIDEO_STREAMING), \
+      /* Camera Terminal: ID, bAssocTerminal, iTerminal, focal min, max, length, bmControl */ \
+      TUD_VIDEO_DESC_CAMERA_TERM(UVC_ENTITY_CAP_INPUT_TERMINAL, 0, 0, 0, 0, 0, 0), \
       TUD_VIDEO_DESC_OUTPUT_TERM(UVC_ENTITY_CAP_OUTPUT_TERMINAL, VIDEO_TT_STREAMING, 0, 1, 0), \
   /* Video stream alt. 0 */ \
   TUD_VIDEO_DESC_STD_VS(ITF_NUM_VIDEO_STREAMING, 0, 0, _stridx), \
     /* Video stream header for without still image capture */ \
     TUD_VIDEO_DESC_CS_VS_INPUT( /*bNumFormats*/1, \
-        /*wTotalLength - bLength */\
-        TUD_VIDEO_DESC_CS_VS_FMT_UNCOMPR_LEN\
-        + TUD_VIDEO_DESC_CS_VS_FRM_UNCOMPR_CONT_LEN\
-        + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN,\
+        /*wTotalLength - bLength */ TUD_VIDEO_DESC_CS_VS_FMT_UNCOMPR_LEN + TUD_VIDEO_DESC_CS_VS_FRM_UNCOMPR_CONT_LEN + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN,\
         _epin, /*bmInfo*/0, /*bTerminalLink*/UVC_ENTITY_CAP_OUTPUT_TERMINAL, \
         /*bStillCaptureMethod*/0, /*bTriggerSupport*/0, /*bTriggerUsage*/0, \
         /*bmaControls(1)*/0), \
@@ -120,7 +136,7 @@ enum {
         /* Video stream frame format */ \
         TUD_VIDEO_DESC_CS_VS_FRM_UNCOMPR_CONT(/*bFrameIndex */1, 0, _width, _height, \
             _width * _height * 16, _width * _height * 16 * _fps, \
-            _width * _height * 16, \
+            _width * _height * 16 / 8, \
             (10000000/_fps), (10000000/_fps), (10000000/_fps)*_fps, (10000000/_fps)), \
         TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING(VIDEO_COLOR_PRIMARIES_BT709, VIDEO_COLOR_XFER_CH_BT709, VIDEO_COLOR_COEF_SMPTE170M), \
   /* VS alt 1 */\
@@ -131,23 +147,17 @@ enum {
 #define TUD_VIDEO_CAPTURE_DESCRIPTOR_MJPEG(_stridx, _epin, _width, _height, _fps, _epsize) \
   TUD_VIDEO_DESC_IAD(ITF_NUM_VIDEO_CONTROL, /* 2 Interfaces */ 0x02, _stridx), \
   /* Video control 0 */ \
-  TUD_VIDEO_DESC_STD_VC(ITF_NUM_VIDEO_CONTROL, 0, _stridx), \
-    TUD_VIDEO_DESC_CS_VC( /* UVC 1.5*/ 0x0150, \
-         /* wTotalLength - bLength */ \
-         TUD_VIDEO_DESC_CAMERA_TERM_LEN + TUD_VIDEO_DESC_OUTPUT_TERM_LEN, \
-         UVC_CLOCK_FREQUENCY, ITF_NUM_VIDEO_STREAMING), \
-      TUD_VIDEO_DESC_CAMERA_TERM(UVC_ENTITY_CAP_INPUT_TERMINAL, 0, 0,\
-                                 /*wObjectiveFocalLengthMin*/0, /*wObjectiveFocalLengthMax*/0,\
-                                 /*wObjectiveFocalLength*/0, /*bmControls*/0), \
+  TUD_VIDEO_DESC_STD_VC(ITF_NUM_VIDEO_CONTROL, 0, _stridx),                                \
+    /* Header: UVC 1.5, length of followed descs, clock (deprecated), streaming interfaces */ \
+    TUD_VIDEO_DESC_CS_VC(0x0150, TUD_VIDEO_DESC_CAMERA_TERM_LEN + TUD_VIDEO_DESC_OUTPUT_TERM_LEN, UVC_CLOCK_FREQUENCY, ITF_NUM_VIDEO_STREAMING), \
+      /* Camera Terminal: ID, bAssocTerminal, iTerminal, focal min, max, length, bmControl */ \
+      TUD_VIDEO_DESC_CAMERA_TERM(UVC_ENTITY_CAP_INPUT_TERMINAL, 0, 0, 0, 0, 0, 0), \
       TUD_VIDEO_DESC_OUTPUT_TERM(UVC_ENTITY_CAP_OUTPUT_TERMINAL, VIDEO_TT_STREAMING, 0, 1, 0), \
   /* Video stream alt. 0 */ \
   TUD_VIDEO_DESC_STD_VS(ITF_NUM_VIDEO_STREAMING, 0, 0, _stridx), \
     /* Video stream header for without still image capture */ \
     TUD_VIDEO_DESC_CS_VS_INPUT( /*bNumFormats*/1, \
-        /*wTotalLength - bLength */\
-        TUD_VIDEO_DESC_CS_VS_FMT_MJPEG_LEN\
-        + TUD_VIDEO_DESC_CS_VS_FRM_MJPEG_CONT_LEN\
-        + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN,\
+        /*wTotalLength - bLength */ TUD_VIDEO_DESC_CS_VS_FMT_MJPEG_LEN + TUD_VIDEO_DESC_CS_VS_FRM_MJPEG_CONT_LEN + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN,\
         _epin, /*bmInfo*/0, /*bTerminalLink*/UVC_ENTITY_CAP_OUTPUT_TERMINAL, \
         /*bStillCaptureMethod*/0, /*bTriggerSupport*/0, /*bTriggerUsage*/0, \
         /*bmaControls(1)*/0), \
@@ -165,4 +175,64 @@ enum {
     /* EP */ \
     TUD_VIDEO_DESC_EP_ISO(_epin, _epsize, 1)
 
+
+#define TUD_VIDEO_CAPTURE_DESCRIPTOR_UNCOMPR_BULK(_stridx, _epin, _width, _height, _fps, _epsize) \
+  TUD_VIDEO_DESC_IAD(ITF_NUM_VIDEO_CONTROL, /* 2 Interfaces */ 0x02, _stridx), \
+  /* Video control 0 */ \
+  TUD_VIDEO_DESC_STD_VC(ITF_NUM_VIDEO_CONTROL, 0, _stridx), \
+    /* Header: UVC 1.5, length of followed descs, clock (deprecated), streaming interfaces */ \
+    TUD_VIDEO_DESC_CS_VC(0x0150, TUD_VIDEO_DESC_CAMERA_TERM_LEN + TUD_VIDEO_DESC_OUTPUT_TERM_LEN, UVC_CLOCK_FREQUENCY, ITF_NUM_VIDEO_STREAMING), \
+      /* Camera Terminal: ID, bAssocTerminal, iTerminal, focal min, max, length, bmControl */ \
+      TUD_VIDEO_DESC_CAMERA_TERM(UVC_ENTITY_CAP_INPUT_TERMINAL, 0, 0, 0, 0, 0, 0), \
+      TUD_VIDEO_DESC_OUTPUT_TERM(UVC_ENTITY_CAP_OUTPUT_TERMINAL, VIDEO_TT_STREAMING, 0, 1, 0), \
+  /* Video stream alt. 0 */ \
+  TUD_VIDEO_DESC_STD_VS(ITF_NUM_VIDEO_STREAMING, 0, 1, _stridx), \
+    /* Video stream header for without still image capture */ \
+    TUD_VIDEO_DESC_CS_VS_INPUT( /*bNumFormats*/1, \
+        /*wTotalLength - bLength */\
+        TUD_VIDEO_DESC_CS_VS_FMT_UNCOMPR_LEN + TUD_VIDEO_DESC_CS_VS_FRM_UNCOMPR_CONT_LEN + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN,\
+        _epin, /*bmInfo*/0, /*bTerminalLink*/UVC_ENTITY_CAP_OUTPUT_TERMINAL, \
+        /*bStillCaptureMethod*/0, /*bTriggerSupport*/0, /*bTriggerUsage*/0, \
+        /*bmaControls(1)*/0), \
+      /* Video stream format */ \
+      TUD_VIDEO_DESC_CS_VS_FMT_YUY2(/*bFormatIndex*/1, /*bNumFrameDescriptors*/1, \
+        /*bDefaultFrameIndex*/1, 0, 0, 0, /*bCopyProtect*/0), \
+        /* Video stream frame format */ \
+        TUD_VIDEO_DESC_CS_VS_FRM_UNCOMPR_CONT(/*bFrameIndex */1, 0, _width, _height, \
+            _width * _height * 16, _width * _height * 16 * _fps, \
+            _width * _height * 16 / 8, \
+            (10000000/_fps), (10000000/_fps), (10000000/_fps)*_fps, (10000000/_fps)), \
+        TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING(VIDEO_COLOR_PRIMARIES_BT709, VIDEO_COLOR_XFER_CH_BT709, VIDEO_COLOR_COEF_SMPTE170M), \
+        TUD_VIDEO_DESC_EP_BULK(_epin, _epsize, 1)
+
+#define TUD_VIDEO_CAPTURE_DESCRIPTOR_MJPEG_BULK(_stridx, _epin, _width, _height, _fps, _epsize) \
+  TUD_VIDEO_DESC_IAD(ITF_NUM_VIDEO_CONTROL, /* 2 Interfaces */ 0x02, _stridx), \
+  /* Video control 0 */ \
+  TUD_VIDEO_DESC_STD_VC(ITF_NUM_VIDEO_CONTROL, 0, _stridx),                                     \
+    /* Header: UVC 1.5, length of followed descs, clock (deprecated), streaming interfaces */ \
+    TUD_VIDEO_DESC_CS_VC(0x0150, TUD_VIDEO_DESC_CAMERA_TERM_LEN + TUD_VIDEO_DESC_OUTPUT_TERM_LEN, UVC_CLOCK_FREQUENCY, ITF_NUM_VIDEO_STREAMING), \
+      /* Camera Terminal: ID, bAssocTerminal, iTerminal, focal min, max, length, bmControl */ \
+      TUD_VIDEO_DESC_CAMERA_TERM(UVC_ENTITY_CAP_INPUT_TERMINAL, 0, 0, 0, 0, 0, 0), \
+      TUD_VIDEO_DESC_OUTPUT_TERM(UVC_ENTITY_CAP_OUTPUT_TERMINAL, VIDEO_TT_STREAMING, 0, UVC_ENTITY_CAP_INPUT_TERMINAL, 0), \
+  /* Video stream alt. 0 */ \
+  TUD_VIDEO_DESC_STD_VS(ITF_NUM_VIDEO_STREAMING, 0, 1, _stridx), \
+    /* Video stream header for without still image capture */ \
+    TUD_VIDEO_DESC_CS_VS_INPUT( /*bNumFormats*/1, \
+        /*wTotalLength - bLength */ TUD_VIDEO_DESC_CS_VS_FMT_MJPEG_LEN + TUD_VIDEO_DESC_CS_VS_FRM_MJPEG_CONT_LEN + TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING_LEN,\
+        _epin, /*bmInfo*/0, /*bTerminalLink*/UVC_ENTITY_CAP_OUTPUT_TERMINAL, \
+        /*bStillCaptureMethod*/0, /*bTriggerSupport*/0, /*bTriggerUsage*/0, \
+        /*bmaControls(1)*/0), \
+      /* Video stream format */ \
+      TUD_VIDEO_DESC_CS_VS_FMT_MJPEG(/*bFormatIndex*/1, /*bNumFrameDescriptors*/1, \
+        /*bmFlags*/0, /*bDefaultFrameIndex*/1, 0, 0, 0, /*bCopyProtect*/0), \
+        /* Video stream frame format */ \
+        TUD_VIDEO_DESC_CS_VS_FRM_MJPEG_CONT(/*bFrameIndex */1, 0, _width, _height, \
+            _width * _height * 16, _width * _height * 16 * _fps, \
+            _width * _height * 16 / 8, \
+            (10000000/_fps), (10000000/_fps), (10000000/_fps)*_fps, (10000000/_fps)), \
+        TUD_VIDEO_DESC_CS_VS_COLOR_MATCHING(VIDEO_COLOR_PRIMARIES_BT709, VIDEO_COLOR_XFER_CH_BT709, VIDEO_COLOR_COEF_SMPTE170M), \
+        /* EP */ \
+        TUD_VIDEO_DESC_EP_BULK(_epin, _epsize, 1)
+
+
 #endif
diff --git a/examples/device/webusb_serial/CMakeLists.txt b/examples/device/webusb_serial/CMakeLists.txt
index abc4d91da..e92a57148 100644
--- a/examples/device/webusb_serial/CMakeLists.txt
+++ b/examples/device/webusb_serial/CMakeLists.txt
@@ -1,15 +1,20 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
 add_executable(${PROJECT})
 
 # Example source
@@ -23,6 +28,6 @@ target_include_directories(${PROJECT} PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src
         )
 
-# Configure compilation flags and libraries for the example... see the corresponding function
-# in hw/bsp/FAMILY/family.cmake for details.
-family_configure_device_example(${PROJECT})
\ No newline at end of file
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} noos)
diff --git a/examples/device/webusb_serial/Makefile b/examples/device/webusb_serial/Makefile
index 5a455078e..7fa475da5 100644
--- a/examples/device/webusb_serial/Makefile
+++ b/examples/device/webusb_serial/Makefile
@@ -1,5 +1,4 @@
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 INC += \
   src \
@@ -9,4 +8,4 @@ INC += \
 EXAMPLE_SOURCE += $(wildcard src/*.c)
 SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/webusb_serial/src/main.c b/examples/device/webusb_serial/src/main.c
index 604d30a83..800d435b8 100644
--- a/examples/device/webusb_serial/src/main.c
+++ b/examples/device/webusb_serial/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -47,7 +47,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -96,6 +96,10 @@ int main(void)
   // init device stack on configured roothub port
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   while (1)
   {
     tud_task(); // tinyusb device task
@@ -103,8 +107,6 @@ int main(void)
     webserial_task();
     led_blinking_task();
   }
-
-  return 0;
 }
 
 // send characters to both CDC and WebUSB
@@ -114,7 +116,7 @@ void echo_all(uint8_t buf[], uint32_t count)
   if ( web_serial_connected )
   {
     tud_vendor_write(buf, count);
-    tud_vendor_flush();
+    tud_vendor_write_flush();
   }
 
   // echo to cdc
@@ -158,7 +160,7 @@ void tud_suspend_cb(bool remote_wakeup_en)
 // Invoked when usb bus is resumed
 void tud_resume_cb(void)
 {
-  blink_interval_ms = BLINK_MOUNTED;
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
@@ -213,7 +215,7 @@ bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_requ
           blink_interval_ms = BLINK_ALWAYS_ON;
 
           tud_vendor_write_str("\r\nWebUSB interface connected\r\n");
-          tud_vendor_flush();
+          tud_vendor_write_flush();
         }else
         {
           blink_interval_ms = BLINK_MOUNTED;
diff --git a/examples/device/webusb_serial/src/usb_descriptors.c b/examples/device/webusb_serial/src/usb_descriptors.c
index cafe2c22b..b01fae8e3 100644
--- a/examples/device/webusb_serial/src/usb_descriptors.c
+++ b/examples/device/webusb_serial/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 #include "usb_descriptors.h"
 
@@ -97,6 +98,13 @@ enum
   #define EPNUM_CDC_OUT    3
   #define EPNUM_VENDOR_IN  4
   #define EPNUM_VENDOR_OUT 5
+#elif CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X
+  // FT9XX doesn't support a same endpoint number with different direction IN and OUT
+  //    e.g EP1 OUT & EP1 IN cannot exist together
+  #define EPNUM_CDC_IN     2
+  #define EPNUM_CDC_OUT    3
+  #define EPNUM_VENDOR_IN  4
+  #define EPNUM_VENDOR_OUT 5
 #else
   #define EPNUM_CDC_IN     2
   #define EPNUM_CDC_OUT    2
@@ -200,53 +208,65 @@ TU_VERIFY_STATIC(sizeof(desc_ms_os_20) == MS_OS_20_DESC_LEN, "Incorrect size");
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
   "TinyUSB CDC",                 // 4: CDC Interface
   "TinyUSB WebUSB"               // 5: Vendor Interface
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }
diff --git a/examples/device/webusb_serial/src/usb_descriptors.h b/examples/device/webusb_serial/src/usb_descriptors.h
index 19f1ff3f3..a1c4a2cf1 100644
--- a/examples/device/webusb_serial/src/usb_descriptors.h
+++ b/examples/device/webusb_serial/src/usb_descriptors.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)