const int numLeds = 12;
int ledPins[numLeds] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13};

void setup() {
  Serial.begin(9600);
  for (int i = 0; i < numLeds; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
Serial.println("Pilih");
}

void loop() {
  int choice = 0;

  if (Serial.available() > 0) {
    choice = Serial.read() - '0';
    Serial.println(choice);

    switch (choice) {
      case 1:
      for (int i = 2; i < numLeds; i+=3) {
        digitalWrite(ledPins[i], HIGH);}
        break;

      case 2:
        for (int i = 2; i < numLeds; i+=3) {
        digitalWrite(ledPins[i], LOW);}
        break;


      case 3:
        for (int i = 0; i < numLeds; i++) {
          digitalWrite(ledPins[i], HIGH);
        }
        break;

      case 4:
        for (int i = 0; i < numLeds; i++) {
          digitalWrite(ledPins[i], HIGH);
          delay(500);
          digitalWrite(ledPins[i], LOW);
        }
        break;

      case 5:
        for (int i = 0; i < numLeds; i++) {
          digitalWrite(ledPins[i], HIGH);
        }
        delay(500);
        for (int i = 0; i < numLeds; i++) {
          digitalWrite(ledPins[i], LOW);
        }
        delay(500);
        break;

      case 6:
        for (int i = 0; i < numLeds; i++) {
          digitalWrite(ledPins[i], LOW);
        }
        break;

      default:
        break;
    }
  }
}