int pinLED = 3;
int pinBUTTON = 2;
void setup() {

Serial.begin(9600);

pinMode(pinLED, OUTPUT);
pinMode(pinBUTTON, INPUT);
Serial.println("Program siap dimulai");

}

void loop() {

  if (digitalRead(pinBUTTON) == LOW) {
  digitalWrite(pinLED, HIGH);
  Serial.println("LED menyala");

  }
  else {

    digitalWrite(pinLED, LOW);
    Serial.println("LED mati");
  }

}