// Dimmer - sends bytes over a serial port
// by David A. Mellis

import processing.serial.*;

Serial port;

void setup()
{
  size(256, 150);
  
  println("Available serial ports:");
  println(Serial.list());
  
  // Uses the first port in this list (number 0).  Change this to
  // select the port corresponding to your Arduino board.  The last
  // parameter (e.g. 9600) is the speed of the communication.  It
  // has to correspond to the value passed to Serial.begin() in your
  // Arduino sketch.
  port = new Serial(this, Serial.list()[0], 9600);  
  
  // If you know the name of the port used by the Arduino board, you
  // can specify it directly like this.
  //port = new Serial(this, "COM1", 9600);
}

void draw()
{
  // draw a gradient from black to white
  for (int i = 0; i < 256; i++) {
    stroke(i);
    line(i, 0, i, 150);
  }
  
  // write the current X-position of the mouse to the serial port as
  // a single byte
  port.write(mouseX);
}