BTRasia.ino

#include <Servo.h>

void setup() {
  // put your setup code here, to run once:
    Serial.begin(9600);
    pinMode(LED_BUILTIN, OUTPUT);
    digitalWrite(LED_BUILTIN, HIGH);
}

void loop() {
  // put your main code here, to run repeatedly:
  while(Serial.available()>0){
    String text = Serial.readString();
    if (text == "open_door") {
      digitalWrite(LED_BUILTIN, LOW);
    } else if (text == "close_door") {
      digitalWrite(LED_BUILTIN, HIGH);
    }
  }
  delay(10);
}