int LED1 = 4;
int LED2 = 3;
int LED3 = 2;

void setup() {
  // put your setup code here, to run once:
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
pinMode(LED3, OUTPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(LED1,HIGH);
digitalWrite(LED2,LOW);
digitalWrite(LED3,LOW);
Serial.println("Led Merah ON");
delay(1000);

digitalWrite(LED1,LOW);
digitalWrite(LED2,HIGH);
digitalWrite(LED3,LOW);
Serial.println("Led Kuning ON");
delay(1000);

digitalWrite(LED1,LOW);
digitalWrite(LED2,LOW);
digitalWrite(LED3,HIGH);
Serial.println("Led Hijau ON");
delay(1000);

digitalWrite(LED1,LOW);
digitalWrite(LED2,HIGH);
digitalWrite(LED3,LOW);
Serial.println("Led Kuning ON");
delay(1000);

}