const int ledPin = 5;

//setting PWM properties
const int freq = 5000;
const int ledChannel = 0;
const int resolution = 8;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  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(300);
}

  //decrease the LED brightness
  for(int dutyCycle = 255; dutyCycle >= 0; dutyCycle--){
  // changing the LED brightness with PWM
  ledcWrite(ledChannel, dutyCycle);
  delay(300);
  }
}