const int LED = 10;
char message;

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

void loop() {
  // put your main code here, to run repeatedly:
  if (Serial.available() > 0){
    message = Serial.read();
    if (message == '1'){
      digitalWrite(LED,HIGH);
      delay(100);
    } else if (message =='0'){
      digitalWrite(LED,LOW);
      delay(100);
    }
  }
}