I'm interested in controlling cursors and maybe colors with an Arduino and a potentiometer, using Processing.  Simple, dimple, right?

Well, I'm attempting to follow online instructions as closely as possible, but I'm stuck.  I cannot get my analog port to read.

I'm following [/url=OhNeverMindICan'tPostLinks]Arduino Playground's introductory instructions[/url] to get started.  I've installed Firmata Standard on the board.  I've installed the arduino library in the Processor library folder.  I'm pretty sure it's not the hardware, as a simple pot-LED flicker test shows that everything works without Processing involved.  I've set the right serial port, after an error led me down one avenue of research. I'm using this code in Processing to run a classic example as an analog-in-controlled application, simple enough:
Code:

 /*
* Recursive Tree
* by Daniel Shiffman 
*
* Renders a simple tree-like structure via recursion
* Branching angle calculated as a function of horizontal mouse  location
*/ 
import processing.serial.*; // reference the serial library

import cc.arduino.*; // reference the arduino library

Arduino arduino; // create a variable arduino of the Arduino data type

float theta;
void setup() {
  size(200,200);
  smooth(); 
println(Serial.list()); // List all the available serial ports:

arduino = new Arduino(this, Arduino.list()[3], 57600);

}

void draw() {

  background(0);
  frameRate(30);
  stroke(255);
  // Let's pick an angle 0 to 90 degrees based on the mouse position
/* float a = (mouseX / (float) width) * 90f; // original line */
print (arduino.analogRead(3));
float a = (arduino.analogRead(3) / (float) width) * 90f;

 // Convert it to radians
  theta = radians(a);
  // Start the tree from the bottom of the screen
  translate(width/2,height);
  // Draw a line 60 pixels
  line(0,0,0,-60);
  // Move to the end of that line
  translate(0,-60);
  // Start the recursive branching!
  branch(60);

}

void branch(float h) {
  // Each branch will be 2/3rds the size of the previous one
  h *= 0.66f;

  // All recursive functions must have an exit condition!!!!
  // Here, ours is when the length of the branch is 2 pixels or less
  if (h > 2) {
    pushMatrix();    // Save the current state of transformation (i.e. where are we now)
    rotate(theta);   // Rotate by theta
    line(0,0,0,-h);  // Draw the branch
    translate(0,-h); // Move to the end of the branch
    branch(h);       // Ok, now call myself to draw two new branches!!
    popMatrix();     // Whenever we get back here, we "pop" in order to restore the previous matrix state

    // Repeat the same thing, only branch off to the "left" this time!
    pushMatrix();
    rotate(-theta);
    line(0,0,0,-h);
    translate(0,-h);
    branch(h);
    popMatrix();
  }
} 

I get no errors, and after adding the
Code:

print (arduino.analogRead(3)) 
 

I see that there's just no reading of the pot by Processing.  Is there some way to monitor the inputs and outputs to the board through another sketch?  I don't even know.

Firmata Standard is installed on the board, do I also need to have Arduino running for serial monitoring or something?  

Somebody please help me out

Thanks!

Couple ideas:

Make sure Firmata is uploaded to your Arduino (edit: I see you did that :]).

The baud rate to use also depends on which version of Firmata you have.

See here for reference:
http://www.arduino.cc/playground/Interfacing/Processing

Yes. Since you are controlling the Arduino from Processing (rather than running a sketch on Arduino alone), Processing and the board have to communicate.

Version 2 of Firmata runs at 115200 baud.
If you are using the latest version, try:
arduino = new Arduino(this, Arduino.list()[3], 115200);

Haven't done my 5 post yet, so here's the URL: