#define LED_PIN 10

void setup() {

  Serial.begin(9600);

  pinMode(LED_PIN, OUTPUT);

}

void loop() {
   
  
  for(int i = 0; i<=255; i++){
    analogWrite(LED_PIN, i);
    Serial.println(i);
    delay(50);
  }

  for(int i = 255; i>0; i--){
  analogWrite(LED_PIN, i);
  Serial.println(i);
  delay(50);

  }

}