for kinect arduino

//// before setup

const byte FIRST_QUESTION = '?';
const byte FIRST_RESPONSE = 'T';

//// void setup() here
\\\\ end of setup()

//// void loop() here
// put it in the loop

  if (Serial.available()) {
    char first = Serial.read();
    if (first == FIRST_QUESTION) {
      Serial.write(FIRST_RESPONSE);
    }
    else {
      if (first >= '0' && first <= '3'){
        char second = Serial.read();
        if (second == 'J' || second == 'S'){
          unsigned byte trackNumber = first - '0';  // number between 0-3
          char category = second;                   // char 'J' or 'S'
           //  now you can use those variables later on
        }
      }
      else {
        Serial.flush();
        break;
      }
      while (Serial.read() != '\r'){
      }
    }
  }