通过 RMT（Remote Control Transceiver）遥控收发器控制RGB LED

led_strip.h

#ifndef __LED_STRIP_H
#define __LED_STRIP_H

#include "driver/rmt_tx.h"
#include "esp_log.h"

typedef struct {
    uint8_t green;
    uint8_t red;
    uint8_t blue;
} led_color_t;

void led_strip_init(void);

void led_strip_deinit(void);

void led_strip_update(led_color_t color);

#endif

led_strip.c

#include "led_strip.h"

#define STRIP_LEN           1
#define RMT_TX_GPIO         8

static const char *TAG = "LED_STRIP";

static rmt_channel_handle_t rmt_channel_handle;
static rmt_encoder_handle_t rmt_encoder_handle;

/**
 * @brief 初始化
 */
void led_strip_init(void)
{
    rmt_tx_channel_config_t rmt_tx_channel_config = {
        .clk_src = RMT_CLK_SRC_DEFAULT,
        .gpio_num = RMT_TX_GPIO,
        .resolution_hz = 10 * 1000 * 1000, // 10MHz
        .mem_block_symbols = 64,
        .trans_queue_depth = 4,
    };

    ESP_ERROR_CHECK(rmt_new_tx_channel(&rmt_tx_channel_config, &rmt_channel_handle));

    // WS2812B
    rmt_bytes_encoder_config_t bytes_encoder_config = {
        .bit0 = {
            .level0 = 1,
            .duration0 = 4, // 0.4us
            .level1 = 0,
            .duration1 = 8, // 0.8us
        },
        .bit1 = {
            .level0 = 1,
            .duration0 = 8, // 0.8us
            .level1 = 0,
            .duration1 = 4, // 0.4us
        },
    };
    ESP_ERROR_CHECK(rmt_new_bytes_encoder(&bytes_encoder_config, &rmt_encoder_handle));

    rmt_enable(rmt_channel_handle);
}

/**
 * @brief 反初始化
 */
void led_strip_deinit(void)
{
    rmt_del_channel(rmt_channel_handle);
    rmt_del_encoder(rmt_encoder_handle);
}

/**
 * @brief 设置颜色
 */
void led_strip_update(led_color_t color)
{
    ESP_LOGI(TAG, "set color (%d, %d, %d)", color.red, color.green, color.blue);
    led_color_t color_buffer[STRIP_LEN] = {color};
    rmt_transmit_config_t rmt_transmit_config = {
        .loop_count = 0
    };
    ESP_ERROR_CHECK(rmt_transmit(rmt_channel_handle, rmt_encoder_handle, 
        &color_buffer, sizeof(color_buffer), &rmt_transmit_config));
    rmt_tx_wait_all_done(rmt_channel_handle, 0xFF);
}