void setup() {
  // put your setup code here, to run once:
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(9600);
  Serial.println("Masukkan Perintah!");
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available() > 0){
    String Perintah = Serial.readStringUntil("\n");
    Perintah.trim();

    if(Perintah.equalsIgnoreCase("on")){
      Serial.println("LED ON");
      digitalWrite(LED_BUILTIN, HIGH);
    }
    else if(Perintah.equalsIgnoreCase("off")){
      Serial.println("LED OFF");
      digitalWrite(LED_BUILTIN, LOW);
    }
    else{
      Serial.println("Perintah Invalid");
    }
  }
}