Adjustable RGB LED Color Cube project at http://tinkeringetc.blogspot.com/2013/07/adjustable-rgb-led-color-cube.html

RGB_LED_Cube.ino

//*************************************************************************************************
// Adjustable RGB LED Color Cube
//
// By: Dillon Nichols
// http://tinkeringetc.blogspot.com/2013/07/adjustable-rgb-led-color-cube.html
//
// Created in Arduino 1.0.5
//
// Description: 
// Drives four strips of RGB LEDs inside a cube structure by the use of a controller that 
// selects the strip and the color of the strip.
//
// This work is licensed under a Creative Commons Attribution 3.0 Unported License.
//*************************************************************************************************

// Map pins for the color-adjustment potentiometers
int redPot   = 2;
int greenPot = 1;
int bluePot  = 0;

// Map pins for the LEDs
int redLED1   = 13;
int greenLED1 = 12;
int blueLED1  = 11;
int redLED2   = 10;
int greenLED2 = 9;
int blueLED2  = 8;
int redLED3   = 7;
int greenLED3 = 6;
int blueLED3  = 5;
int redLED4   = 4;
int greenLED4 = 3;
int blueLED4  = 2;

// Create variables to store the brightness of each primary color
int redVal   = 0;
int greenVal = 0;
int blueVal  = 0;

// Create variables to set which side of the cube will be adjustable
int oneON   = 0;
int twoON   = 0;
int threeON = 0;
int fourON  = 0;

void setup() {
  // Set up all of the LED pins as outputs
  pinMode(redLED1,   OUTPUT);
  pinMode(greenLED1, OUTPUT);
  pinMode(blueLED1,  OUTPUT);
  pinMode(redLED2,   OUTPUT);
  pinMode(greenLED2, OUTPUT);
  pinMode(blueLED2,  OUTPUT);
  pinMode(redLED3,   OUTPUT);
  pinMode(greenLED3, OUTPUT);
  pinMode(blueLED3,  OUTPUT);
  pinMode(redLED4,   OUTPUT);
  pinMode(greenLED4, OUTPUT);
  pinMode(blueLED4,  OUTPUT);
  
  // Set up interrupts for the four buttons
  attachInterrupt(5, one,   FALLING);
  attachInterrupt(3, two,   FALLING);
  attachInterrupt(2, three, FALLING);
  attachInterrupt(4, four,  FALLING);
}

void loop() {
  // Read the analog potentiometer value and scale from 0-1023 to 0-255
  redVal = analogRead(redPot) / 4;
  greenVal = analogRead(greenPot) / 4;
  blueVal = analogRead(bluePot) / 4;

  // Change the side chosen by the button interupt to the color from the potentiometers
  if (oneON == 1) {
    analogWrite(redLED1, redVal);
    analogWrite(greenLED1, greenVal);
    analogWrite(blueLED1, blueVal);
  }
  
  if (twoON == 1) {
    analogWrite(redLED2, redVal);
    analogWrite(greenLED2, greenVal);
    analogWrite(blueLED2, blueVal);
  }
  
  if (threeON == 1) {
    analogWrite(redLED3, redVal);
    analogWrite(greenLED3, greenVal);
    analogWrite(blueLED3, blueVal);
  }
  
  if (fourON == 1) {
    analogWrite(redLED4, redVal);
    analogWrite(greenLED4, greenVal);
    analogWrite(blueLED4, blueVal);
  }
}

// Interrupt routines to select from one of the four sides
void one() {
  oneON   = 1;
  twoON   = 0;
  threeON = 0;
  fourON  = 0;
}

void two() {
  oneON   = 0;
  twoON   = 1;
  threeON = 0;
  fourON  = 0;
}

void three() {
  oneON   = 0;
  twoON   = 0;
  threeON = 1;
  fourON  = 0;
}

void four() {
  oneON   = 0;
  twoON   = 0;
  threeON = 0;
  fourON  = 1;
}