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];
  static rmt_obj_t* rmt_send = NULL;
  static bool initialized = false;

  uint8_t _pin = pin;
#ifdef RGB_BUILTIN
  if(pin == RGB_BUILTIN){
    _pin = RGB_BUILTIN-SOC_GPIO_PIN_COUNT;
  }
#endif

  if(!initialized){
    if((rmt_send = rmtInit(_pin, RMT_TX_MODE, RMT_MEM_64)) == NULL){
        log_e("RGB LED driver initialization failed!");
        rmt_send = NULL;
        return;
    }
    rmtSetTick(rmt_send, 100);
    initialized = true;
  }

  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(rmt_send, led_data, 24);
}