const int ledPin = 13;  

void setup() {
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600); 
}

void loop() {
  if (Serial.available() > 0) {   
    char data = Serial.read();   
    if (data == '1') {           
      digitalWrite(ledPin, HIGH);
      delay(200);                 
      digitalWrite(ledPin, LOW);
    }
  }
}