int lampuHijau = 8;
int lampuKuning = 12;
int lampuMerah = 13;

void setup() {
  pinMode(lampuHijau, OUTPUT);
  pinMode(lampuKuning, OUTPUT);
  pinMode(lampuMerah, OUTPUT);
}

void loop() {
  digitalWrite(lampuHijau, HIGH);   
  delay(15000);
  digitalWrite(lampuHijau, LOW);
  digitalWrite(lampuKuning, HIGH);
  delay(1000);
  digitalWrite(lampuKuning, LOW);                         
  digitalWrite(lampuMerah, HIGH);                     
  delay(15000);
  digitalWrite(lampuMerah, LOW);                     
  digitalWrite(lampuKuning, HIGH);
  delay(1000);
  digitalWrite(lampuKuning, LOW);                     
}