int lampu_NURUL =2;
int lampu_NURUL2 =4;

void setup() {
pinMode(lampu_NURUL, OUTPUT);
pinMode(lampu_NURUL2, OUTPUT);
}

void loop() {
  digitalWrite(lampu_NURUL, HIGH);
  digitalWrite(lampu_NURUL2, LOW);
delay(500);

digitalWrite(lampu_NURUL, LOW);
digitalWrite(lampu_NURUL2, HIGH);
delay(500);
}