#define LED 13

void setup( void ) {
  Serial.begin(9600);
  
  pinMode(LED, OUTPUT);
  Serial.println("");
}

String data_in = "";

void loop( void ) {
  
  /* BEG capture serial input (from B1) */
  if(Serial.available()){
    char data_in = Serial.read();
    if(data_in == '1')      
      digitalWrite(LED, HIGH);
    else if(data_in =='0')  
      digitalWrite(LED, LOW);
    Serial.println(data_in);

  }
  /* END capture serial input (from B1) */
}