Processing and Arduino

INTRODUCTION
I was thinking about this opportunity to communicate between Processing and Arduino and I made a simple example that I get a visual feedback from a light sensor.
The idea is to create a scenery and change it depending on the value of the sensor. Basically show the sun with a brightness color when there is a lot of light and then show the moon with a dark background  when there isn't enough light.

PROCESSING
What you need is the Processing IDE and try to play with it, create a scenery and some animation.
What I did is a simple animation of moving a circle up and down, and then change the background color.
As soon as you have something working, you need to implement Firmata for Processing  (http://www.arduino.cc/playground/Interfacing/Processing).

***I found an issue with Linux, if you want to communicate with your Arduino, you need to make sure that  with your Arduino IDE works and then lunch this command:

sudo ln -s /dev/ttyACM3 /dev/ttyS42
ACM3 = Arduino port
ttyS42 = This port will be use on processing

You need to change your connection line to something like that:
 arduino = new Arduino(this, "/dev/ttyS42", 57600);

Otherwise if you are Windows user you need to write something like that:
  arduino = new Arduino(this, Arduino.list()[0], 57600);
[0] = Try to change the number zero with something else if you are getting some connection errors.

I want to tell you the truth, you are going to think that Processing is another complicate language and you will never use it, NO that is absolute wrong, I made this project in about 2 hours, Processing is very simple and you can find a lot of examples and libraries.


ARDUINO
You need to upload on your Arduino the Standard Firmata that is on your example menu.
Ok, the last step is to connect your device on your Arduino, I bought a light sensor that works with an analog pin and I attached it on the pin A0.

Change your Processing example to get the value , in my case the command to get the analog input was:
arduino.analogRead(0);

EXAMPLE
This is my example that I made with Processing and Arduino, you can check the video on the bottom, please don't care about my design skills :).

import processing.serial.*;
import de.looksgood.ani.*;
import cc.arduino.*;
import guicomponents.*;

//sudo ln -s /dev/ttyACM3 /dev/ttyS42
//Pin A0
Arduino arduino;

color off = color(4, 79, 111);
color on = color(84, 145, 158);

float sunX = 800, sunY = 100;
float moonX = 800, moonY = 800;
int light = 50;
float lightMoon = 0, lightSun= 0, lightSky = 191, lightSky2 = 255;
GWSlider sdr1;

int a = 0;

void setup() {
  size(1024, 800);
  arduino = new Arduino(this, "/dev/ttyS42", 57600);
  Ani.init(this);
  sdr1 = new GWSlider(this,20,20,260);
  sdr1.setLimits(0, 0, 1000);
}

void draw() {
  background(0, lightSky, lightSky2);
  stroke(on);
  displaySheme(light);
  showVillage();
  light = arduino.analogRead(0);

  fill(0, 102, 153);
  text("Current light: "+light,50,780);
}

void showVillage() {
  //Draw the grass
  fill(50, 205, 50);
  rect(0, 600, 1024, 200);
  //Draw the house
  stroke(off);
  fill(139, 69, 19);
  rect(100, 450, 160, 200);

  fill(211, 211, 211);
  rect(120, 480, 50, 50);
  rect(190, 480, 50, 50);

  rect(160, 580, 50, 70);

  fill(193, 205, 193);
  triangle(100, 450, 180, 400, 260, 450);
}

void showSun() {
  fill(255, 255, lightSun);
  ellipse(sunX, sunY, 100, 100);
}

void showMoon() {
  fill(255, 255, 255);
  ellipse(moonX, moonY, 100, 100);
}

void displaySheme(int light) {
  float newY = constrain(map(light, a, 100, 1100, 100), 100, 1100);
  float newC = constrain(map(light, a, 100, 255, 0), 0, 255);
  float newB = constrain(map(light, a, 161, 0, 255), 0, 255 );

  if (newY > 600) {
    Ani.to(this, 1.5, "sunY", newY);
    Ani.to(this, 1.5, "lightSun", newC);
    sunY = 700;  
    Ani.to(this, 1.5, "moonY", 100);
  }
  else {
    Ani.to(this, 1.5, "sunY", newY);
    Ani.to(this, 1.5, "lightSun", newC);
    Ani.to(this, 1.5, "moonY", 700);
  }
  //change the sky
  Ani.to(this, 1.5, "lightSky", newB);
  Ani.to(this, 1.5, "lightSky2", newB);
  showSun();
  showMoon();
}

void handleSliderEvents(GSlider slider) {
  a = slider.getValue();
  println("integer value:" + slider.getValue() + " float value:" + slider.getValuef());
}

VIDEO