import processing.serial.*;     // import the Processing serial library
Serial myPort;                  // The serial port

void setup() {
  // List all the available serial ports
  println(Serial.list());

  // I know that the first port in the serial list on my mac
  // is always my  Arduino module, so I open Serial.list()[0].
  // Change the 0 to the appropriate number of the serial port
  // that your microcontroller is attached to.
  String portName = Serial.list()[0];
  myPort = new Serial(this, portName, 9600);
}