int led_ungu = 13;
int led_biru = 12;


void setup() {
  pinMode(led_ungu,OUTPUT);
  pinMode(led_biru,OUTPUT);

}

void loop() {
  nyala(led_biru);
  nyala(led_ungu);
  delay(500);
  mati(led_biru);
  mati(led_ungu);
  delay(500);

}

 void nyala(int pin){
  digitalWrite(pin,HIGH);
 }

  void mati(int pin){
  digitalWrite(pin,LOW);
 }