int led1 = 2; //LED KUNING
int led2 = 4; //LED BIRU
int led3 = 6; //LED MERAH
int led4 = 8; //LED HIJAU
int dt = 1000;

void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
}

void loop() {
  for(int i=1; i<=5; i++){
    if(i==1){
      digitalWrite(led1, HIGH);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
      digitalWrite(led4, LOW);
      delay(dt);
    }
    else if(i==2){
      digitalWrite(led1, HIGH);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, LOW);
      digitalWrite(led4, LOW);
      delay(dt);
    }
    else if(i==3){
      digitalWrite(led1, HIGH);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, HIGH);
      digitalWrite(led4, LOW);
      delay(dt);
    }
    else if(i==4){
      digitalWrite(led1, HIGH);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, HIGH);
      digitalWrite(led4, HIGH);
      delay(dt);
    }
    else {
      digitalWrite(led1, LOW);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
      digitalWrite(led4, LOW);
      delay(dt);
    }
}
}