diff options
| author | HiFiPhile <[email protected]> | 2026-06-22 21:30:58 +0200 |
|---|---|---|
| committer | HiFiPhile <[email protected]> | 2026-06-22 21:30:58 +0200 |
| commit | 693cdce08e14833f26f4e8a1f26e4fd546be4c35 (patch) | |
| tree | 7667d2223dc32d9f21b5b60ab200e64ed46e3e20 /examples/device/printer_to_cdc/src/main.c | |
| parent | 41e9eaa65a935136085d78ec4b99c81ff991b560 (diff) | |
| parent | cd3561bf158afd5a5718904b8139a338d1e3b67c (diff) | |
Merge remote-tracking branch 'tinyusb/master' into pr-osal-spin-deinit
Signed-off-by: HiFiPhile <[email protected]>
Diffstat (limited to 'examples/device/printer_to_cdc/src/main.c')
| -rw-r--r-- | examples/device/printer_to_cdc/src/main.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/examples/device/printer_to_cdc/src/main.c b/examples/device/printer_to_cdc/src/main.c new file mode 100644 index 000000000..ffaf709b4 --- /dev/null +++ b/examples/device/printer_to_cdc/src/main.c @@ -0,0 +1,117 @@ +/* + * The MIT License (MIT) + * + * Copyright (c) 2026 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. + * + */ + +/* This example demonstrates a USB Printer + CDC composite device. + * Data received on the Printer interface is forwarded to the CDC serial port, + * and data received on the CDC serial port is forwarded back to the Printer interface. + * + * To test: + * 1. Flash the device + * 2. Open a serial terminal on the CDC port (e.g. /dev/ttyACM0) + * 3. Send data to the printer: echo "hello" > /dev/usb/lp0 + * 4. The data appears on the CDC serial terminal + * 5. Type in the serial terminal to send data back through the printer TX + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#include "bsp/board_api.h" +#include "tusb.h" + +#include "usb_descriptors.h" + +// -------------------------------------------------------------------+ +// Tasks +// -------------------------------------------------------------------+ + +// Forward data from Printer RX to CDC TX +static void printer_to_cdc_task(void) { + uint32_t avail = tud_printer_read_available(); + if (avail == 0 || !tud_cdc_write_available()) { + return; + } + + uint8_t buf[64]; + uint32_t count = tud_printer_read(buf, TU_MIN(sizeof(buf), tud_cdc_write_available())); + if (count > 0) { + tud_cdc_write(buf, count); + tud_cdc_write_flush(); + } +} + +// Forward data from CDC RX to Printer TX +static void cdc_to_printer_task(void) { + uint32_t avail = tud_printer_write_available(); + if (tud_cdc_available() == 0 || avail == 0) { + return; + } + + uint8_t buf[64]; + uint32_t count = tud_cdc_read(buf, TU_MIN(sizeof(buf), avail)); + if (count > 0) { + tud_printer_write(buf, count); + tud_printer_write_flush(); + } +} + +int main(void) { + board_init(); + // init device stack on configured roothub port + tusb_rhport_init_t dev_init = {.role = TUSB_ROLE_DEVICE, .speed = TUSB_SPEED_AUTO}; + tusb_init(BOARD_TUD_RHPORT, &dev_init); + board_init_after_tusb(); + + while (1) { + tud_task(); // tinyusb device task + printer_to_cdc_task(); // forward printer data to CDC + cdc_to_printer_task(); // forward CDC data to printer + } +} + +//--------------------------------------------------------------------+ +// Printer callbacks +//--------------------------------------------------------------------+ + +void tud_printer_rx_cb(uint8_t itf) { + (void)itf; +} + +// IEEE 1284 Device ID: first 2 bytes are big-endian total length (including the 2 length bytes). +// The rest is the Device ID string using standard abbreviated keys. +static const char printer_device_id[] = + "\x00\x34" // total length = 52 = 0x0034 (big-endian) + "MFG:TinyUSB;" + "MDL:Printer to CDC;" + "CMD:PS;" + "CLS:PRINTER;"; + +TU_VERIFY_STATIC(sizeof(printer_device_id) - 1 == 52, "device ID length mismatch"); + +uint8_t const *tud_printer_get_device_id_cb(uint8_t itf) { + (void)itf; + return (uint8_t const *)printer_device_id; +} |
