int ledhijau1=0;
int ledkuning1=1;
int ledmerah1=2;
void setup() {
  // put your setup code here, to run once:
pinMode(ledhijau1, OUTPUT);
pinMode(ledkuning1, OUTPUT);
pinMode(ledmerah1, OUTPUT);
}

void semua_mati(){
digitalWrite(ledhijau1, LOW);
digitalWrite(ledkuning1, LOW);
digitalWrite(ledmerah1, LOW);  
}

void hijau_nyala(){
digitalWrite(ledhijau1, HIGH);
digitalWrite(ledkuning1, LOW);
digitalWrite(ledmerah1, LOW);  
}

void kuning_nyala(){
digitalWrite(ledhijau1, LOW);
digitalWrite(ledkuning1, HIGH);
digitalWrite(ledmerah1, LOW);  
}

void merah_nyala(){
digitalWrite(ledhijau1, LOW);
digitalWrite(ledkuning1, LOW);
digitalWrite(ledmerah1, 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(3000);
transit_kuning();
merah_nyala();
delay(3000);
transit_kuning();
}