const int ledPin = 13;      // the pin that the LED is attached to
int tx=1;
int rx=0;
int val=0;
    void setup()
    {
      // initialize the serial communication:
      Serial.begin(9600); //baud rate - make sure it matches that of the module you got:
      pinMode(tx, OUTPUT);
      pinMode(rx, INPUT);
      digitalWrite(ledPin, LOW);// initialize the ledPin as an output:
      pinMode(ledPin, OUTPUT);
    }

    void loop() {

    if (Serial.available() > 0) {
    val = Serial.read();
  Serial.println(val);}


          switch (val) {
        case 0:
          digitalWrite(ledPin, LOW);
          break;
        case 1:
          digitalWrite(ledPin,HIGH);
          break;
        case 2:digitalWrite(ledPin, HIGH);
          delay(100);
          digitalWrite(ledPin, LOW);
          delay(100);
         default:

          break;
          }}