const int ledPin1=16;
const int ledPin2=17;
const int ledPin3=5;

const int freq=5000;
const int ledChannel=0;
const int resolution=8;
void setup(){
 ledcSetup(ledChannel,freq,resolution);
 ledcAttachPin(ledPin1,ledChannel);
 ledcAttachPin(ledPin2,ledChannel);
 ledcAttachPin(ledPin3,ledChannel);
}
void loop(){
  for(int dutyCycle=0;dutyCycle<=255;dutyCycle++){
  ledcWrite(ledChannel, dutyCycle);
    delay(15); 
  }
  for(int dutyCycle=255;dutyCycle>=0;dutyCycle--){
  ledcWrite(ledChannel,dutyCycle);
  delay(15);
}
}




// // the number of the LED pin
// const int ledPin = 16;  // 16 corresponds to GPIO16

// // setting PWM properties
// const int freq = 5000;
// const int ledChannel = 0;
// const int resolution = 8;
 
// void setup(){
//   // configure LED PWM functionalitites
//   ledcSetup(ledChannel, freq, resolution);
  
//   // attach the channel to the GPIO to be controlled
//   ledcAttachPin(ledPin, ledChannel);
// }
 
// void loop(){
//   // increase the LED brightness
//   for(int dutyCycle = 0; dutyCycle <= 255; dutyCycle++){   
//     // changing the LED brightness with PWM
//     ledcWrite(ledChannel, dutyCycle);
//     delay(15);
//   }

//   // decrease the LED brightness
//   for(int dutyCycle = 255; dutyCycle >= 0; dutyCycle--){
//     // changing the LED brightness with PWM
//     ledcWrite(ledChannel, dutyCycle);   
//     delay(15);
//   }
// }