esp32-hal-rgb-led.c

#include "esp32-hal-rgb-led.h"


void neopixelWrite(uint8_t pin, uint8_t red_val, uint8_t green_val, uint8_t blue_val){
  rmt_data_t led_data[24];

  // Verify if the pin used is RGB_BUILTIN and fix GPIO number
#ifdef RGB_BUILTIN
  pin = pin == RGB_BUILTIN ? pin - SOC_GPIO_PIN_COUNT : pin;
#endif
  if (!rmtInit(pin, RMT_TX_MODE, RMT_MEM_NUM_BLOCKS_1, 10000000)) {
    log_e("RGB LED driver initialization failed for GPIO%d!", pin);
    return;
  }

  int color[] = {green_val, red_val, blue_val};  // Color coding is in order GREEN, RED, BLUE
  int i = 0;
  for (int col = 0; col < 3; col++ ) {
    for (int bit = 0; bit < 8; bit++) {
      if ((color[col] & (1 << (7 - bit)))) {
        // HIGH bit
        led_data[i].level0 = 1; // T1H
        led_data[i].duration0 = 8; // 0.8us
        led_data[i].level1 = 0; // T1L
        led_data[i].duration1 = 4; // 0.4us
      } else {
        // LOW bit
        led_data[i].level0 = 1; // T0H
        led_data[i].duration0 = 4; // 0.4us
        led_data[i].level1 = 0; // T0L
        led_data[i].duration1 = 8; // 0.8us
      }
      i++;
    }
  }
  rmtWrite(pin, led_data, RMT_SYMBOLS_OF(led_data), RMT_WAIT_FOR_EVER);
}