void serialEvent(Serial myPort) { 
  // read the serial buffer:
  String myString = myPort.readStringUntil('\n');
  // if you got any bytes other than the linefeed:
  if (myString != null) {

    myString = trim(myString);

    // if you haven't heard from the microncontroller yet, listen:
    if (firstContact == false) {
      if (myString.equals("hello")) { 
        myPort.clear();          // clear the serial port buffer
        firstContact = true;     // you've had first contact from the microcontroller
        myPort.write('A');       // ask for more
      } 
    } 
    // if you have heard from the microcontroller, proceed:
    else {
      // split the string at the commas
      // and convert the sections into integers:
      int sensors[] = int(split(myString, ','));

      // print out the values you got:
      for (int sensorNum = 0; sensorNum < sensors.length; sensorNum++) {
        print("Sensor " + sensorNum + ": " + sensors[sensorNum] + "\t"); 
      }
      // add a linefeed after all the sensor values are printed:
      println();
      if (sensors.length > 1) {
        xpos = map(sensors[0], 430,580,0,width);
        ypos = map(sensors[1], 430,580,0,height);
        fgcolor = sensors[2] * 255;
      }
    }
    // when you've parsed the data you have, ask for more:
    myPort.write("A");
  }
}