Automatically adjust Ubuntu monitor brightness based on Ambient lighting

ambient-display.pde

var five = require("johnny-five"),
  board, photoresistor;
var exec = require('child_process').exec;

board = new five.Board();

board.on("ready", function() {

  // Create a new `photoresistor` hardware instance.
  photoresistor = new five.Sensor({
    pin: "A0",
    freq: 1000
  });


  // "data" get the current reading from the photoresistor
  photoresistor.on("data", function() {
    percent = (this.value/1024) * 100
    console.log("Setting Brightness to: ", percent);
    
    //uses this tool xbacklight to set brightness
    exec("xbacklight -set " +  percent);
  });
});

Circuit Diagram
http://i.imgur.com/hqdx8Vn.png