#define LED1 19
#define LED2 18
#define LED3 15
const int pinChannel0 = 0;
const int pinChannel1 = 1;
const int pinChannel2 = 2;
const int freq = 1000;
const int resolution = 8;
int value_PWM;

void setup() {
  Serial.begin(115200);
  
  ledcSetup(pinChannel0, freq, resolution);
  ledcSetup(pinChannel1, freq, resolution);
  ledcSetup(pinChannel2, freq, resolution);

  ledcAttachPin(LED1, pinChannel0);
  ledcAttachPin(LED2, pinChannel1);
  ledcAttachPin(LED3, pinChannel2);
}

void loop() {
  for (value_PWM = 0; value_PWM < 255; value_PWM++) {
    ledcWrite(pinChannel0, value_PWM);
    ledcWrite(pinChannel1, value_PWM - 6);
    ledcWrite(pinChannel2, value_PWM - 7);

    Serial.println(value_PWM);
    delay(20);
  }

  for (value_PWM = 255; value_PWM > 8; value_PWM--) {
    ledcWrite(pinChannel0, value_PWM);
    ledcWrite(pinChannel1, value_PWM + 4);
    ledcWrite(pinChannel2, value_PWM + 7);

    Serial.println(value_PWM);
    delay(20);
  }
}