int buttonPin = 2;
int ledPin = 9;
int buttonState = 0;
int brightness = 5;
int fadeAmount = 5;
void setup() {
  pinMode(ledPin,OUTPUT);
  pinMode(buttonPin,INPUT);
}

void loop() {
  buttonState = digitalRead(buttonPin);
  if (buttonState == LOW) {
    analogWrite(ledPin, brightness);
    brightness = brightness + fadeAmount;
    if (brightness == 0 || brightness == 255){
      fadeAmount = -fadeAmount;
    }
    else{
      digitalWrite(ledPin,LOW);
    
    }
  }
}