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/*
* SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include "esp_check.h"
#include "led_strip_rmt_encoder.h"
static const char *TAG = "led_rmt_encoder";
typedef struct {
rmt_encoder_t base;
rmt_encoder_t *bytes_encoder;
rmt_encoder_t *copy_encoder;
int state;
rmt_symbol_word_t reset_code;
} rmt_led_strip_encoder_t;
static size_t rmt_encode_led_strip(rmt_encoder_t *encoder, rmt_channel_handle_t channel, const void *primary_data, size_t data_size, rmt_encode_state_t *ret_state)
{
rmt_led_strip_encoder_t *led_encoder = __containerof(encoder, rmt_led_strip_encoder_t, base);
rmt_encoder_handle_t bytes_encoder = led_encoder->bytes_encoder;
rmt_encoder_handle_t copy_encoder = led_encoder->copy_encoder;
rmt_encode_state_t session_state = 0;
rmt_encode_state_t state = 0;
size_t encoded_symbols = 0;
switch (led_encoder->state) {
case 0: // send RGB data
encoded_symbols += bytes_encoder->encode(bytes_encoder, channel, primary_data, data_size, &session_state);
if (session_state & RMT_ENCODING_COMPLETE) {
led_encoder->state = 1; // switch to next state when current encoding session finished
}
if (session_state & RMT_ENCODING_MEM_FULL) {
state |= RMT_ENCODING_MEM_FULL;
goto out; // yield if there's no free space for encoding artifacts
}
// fall-through
case 1: // send reset code
encoded_symbols += copy_encoder->encode(copy_encoder, channel, &led_encoder->reset_code,
sizeof(led_encoder->reset_code), &session_state);
if (session_state & RMT_ENCODING_COMPLETE) {
led_encoder->state = 0; // back to the initial encoding session
state |= RMT_ENCODING_COMPLETE;
}
if (session_state & RMT_ENCODING_MEM_FULL) {
state |= RMT_ENCODING_MEM_FULL;
goto out; // yield if there's no free space for encoding artifacts
}
}
out:
*ret_state = state;
return encoded_symbols;
}
static esp_err_t rmt_del_led_strip_encoder(rmt_encoder_t *encoder)
{
rmt_led_strip_encoder_t *led_encoder = __containerof(encoder, rmt_led_strip_encoder_t, base);
rmt_del_encoder(led_encoder->bytes_encoder);
rmt_del_encoder(led_encoder->copy_encoder);
free(led_encoder);
return ESP_OK;
}
static esp_err_t rmt_led_strip_encoder_reset(rmt_encoder_t *encoder)
{
rmt_led_strip_encoder_t *led_encoder = __containerof(encoder, rmt_led_strip_encoder_t, base);
rmt_encoder_reset(led_encoder->bytes_encoder);
rmt_encoder_reset(led_encoder->copy_encoder);
led_encoder->state = 0;
return ESP_OK;
}
esp_err_t rmt_new_led_strip_encoder(const led_strip_encoder_config_t *config, rmt_encoder_handle_t *ret_encoder)
{
esp_err_t ret = ESP_OK;
rmt_led_strip_encoder_t *led_encoder = NULL;
ESP_GOTO_ON_FALSE(config && ret_encoder, ESP_ERR_INVALID_ARG, err, TAG, "invalid argument");
ESP_GOTO_ON_FALSE(config->led_model < LED_MODEL_INVALID, ESP_ERR_INVALID_ARG, err, TAG, "invalid led model");
led_encoder = calloc(1, sizeof(rmt_led_strip_encoder_t));
ESP_GOTO_ON_FALSE(led_encoder, ESP_ERR_NO_MEM, err, TAG, "no mem for led strip encoder");
led_encoder->base.encode = rmt_encode_led_strip;
led_encoder->base.del = rmt_del_led_strip_encoder;
led_encoder->base.reset = rmt_led_strip_encoder_reset;
rmt_bytes_encoder_config_t bytes_encoder_config;
if (config->led_model == LED_MODEL_SK6812) {
bytes_encoder_config = (rmt_bytes_encoder_config_t) {
.bit0 = {
.level0 = 1,
.duration0 = 0.3 * config->resolution / 1000000, // T0H=0.3us
.level1 = 0,
.duration1 = 0.9 * config->resolution / 1000000, // T0L=0.9us
},
.bit1 = {
.level0 = 1,
.duration0 = 0.6 * config->resolution / 1000000, // T1H=0.6us
.level1 = 0,
.duration1 = 0.6 * config->resolution / 1000000, // T1L=0.6us
},
.flags.msb_first = 1 // SK6812 transfer bit order: G7...G0R7...R0B7...B0(W7...W0)
};
} else if (config->led_model == LED_MODEL_WS2812) {
// different led strip might have its own timing requirements, following parameter is for WS2812
bytes_encoder_config = (rmt_bytes_encoder_config_t) {
.bit0 = {
.level0 = 1,
.duration0 = 0.3 * config->resolution / 1000000, // T0H=0.3us
.level1 = 0,
.duration1 = 0.9 * config->resolution / 1000000, // T0L=0.9us
},
.bit1 = {
.level0 = 1,
.duration0 = 0.9 * config->resolution / 1000000, // T1H=0.9us
.level1 = 0,
.duration1 = 0.3 * config->resolution / 1000000, // T1L=0.3us
},
.flags.msb_first = 1 // WS2812 transfer bit order: G7...G0R7...R0B7...B0
};
} else {
assert(false);
}
ESP_GOTO_ON_ERROR(rmt_new_bytes_encoder(&bytes_encoder_config, &led_encoder->bytes_encoder), err, TAG, "create bytes encoder failed");
rmt_copy_encoder_config_t copy_encoder_config = {};
ESP_GOTO_ON_ERROR(rmt_new_copy_encoder(©_encoder_config, &led_encoder->copy_encoder), err, TAG, "create copy encoder failed");
uint32_t reset_ticks = config->resolution / 1000000 * 50 / 2; // reset code duration defaults to 50us
led_encoder->reset_code = (rmt_symbol_word_t) {
.level0 = 0,
.duration0 = reset_ticks,
.level1 = 0,
.duration1 = reset_ticks,
};
*ret_encoder = &led_encoder->base;
return ESP_OK;
err:
if (led_encoder) {
if (led_encoder->bytes_encoder) {
rmt_del_encoder(led_encoder->bytes_encoder);
}
if (led_encoder->copy_encoder) {
rmt_del_encoder(led_encoder->copy_encoder);
}
free(led_encoder);
}
return ret;
}
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