byte LED_13 = 13;
byte LED_12 = 12;
int tnd = 500;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(LED_13, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(LED_13, HIGH);
  delay(tnd);
  digitalWrite(LED_13,LOW);
  delay(tnd);

  static char comm=0;
  if(Serial.available()>0) {
   comm = Serial.read();
   while(Serial.available()>0)Serial.read();
  }
  if(comm == '1'){
    digitalWrite(LED_12, HIGH);

  }
  if(comm == '2'){
    digitalWrite(LED_12, LOW);

  }
  

}