int ledhijau=0;
int ledkuning=1;
int ledmerah=2;

void setup() {
  // put your setup code here, to run once:
pinMode(ledhijau, OUTPUT);
pinMode(ledkuning, OUTPUT);
pinMode(ledmerah, OUTPUT);
}

void semua_mati(){
digitalWrite(ledhijau, LOW);
digitalWrite(ledkuning, LOW);
digitalWrite(ledmerah, LOW);  
}

void hijau_nyala(){
digitalWrite(ledhijau, HIGH);
digitalWrite(ledkuning, LOW);
digitalWrite(ledmerah, LOW);  
}

void kuning_nyala(){
digitalWrite(ledhijau, LOW);
digitalWrite(ledkuning, HIGH);
digitalWrite(ledmerah, LOW);  
}

void merah_nyala(){
digitalWrite(ledhijau, LOW);
digitalWrite(ledkuning, LOW);
digitalWrite(ledmerah, HIGH);
}

void transit_kuning(){
  for (int i=1; i<=3;i++){
  kuning_nyala();
  delay(500);
  semua_mati();
  delay(500);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
hijau_nyala();
delay(5000);
transit_kuning();
merah_nyala();
delay(5000);
transit_kuning();
}