void setup() {
Serial.begin(9600);
pinMode(5, OUTPUT);//lampu hijau 
pinMode(6, OUTPUT);//lampu kuning
pinMode(7, OUTPUT);//lampu merah 

}

void loop() {
digitalWrite(5, HIGH);
Serial.println("Lampu Hijau Menyala");
delay(3000);
digitalWrite(5, LOW);
Serial.println("Lampu Hijau Mati");
delay(3000);
digitalWrite(6, HIGH);
Serial.println("Lampu Kuning Menyala");
delay(3000);
digitalWrite(6, LOW);
Serial.println("Lampu Kuning Mati");
delay(3000);
digitalWrite(7, HIGH);
Serial.println("Lampu Merah Menyala");
delay(3000);
digitalWrite(7, LOW);
Serial.println("Lampu Merah Mati");
delay(3000);
}