La led RGB utilisée: http://www.selectronic.fr/upload/produit/fichetechnique/0567.pdf

Avec l'arduino, la tension d'entrée est de 5V. Pour chaque patte R, G, B de la LED, il faut calculer la résistance nécessaire avec $R = \frac{(Valim - Vref)}{I}$

rgb_led.pde

const char steps[6][3] = {
  {0, 1, 0},  // start from red  (255, 0, 0) and go to yellow  (255, 255, 0)
  {-1, 0, 0},  // go to green (0, 255, 0)
  {0, 0, 1},  // go to  cyan  (0, 255, 255)
  {0, -1, 0},  // go to blue  (0, 0, 255)
  {1, 0, 0},  //  go to magenta  (255, 0, 255)
  {0, 0, -1},  // go back to red (255, 0, 0)
};
 
int rpin = 9;
int gpin = 10;
int bpin = 11;
 
int pot_pin = 0;
 
void setup()                    // run once, when the sketch starts
{
  pinMode(rpin, OUTPUT);   // sets the pin as output
  pinMode(gpin, OUTPUT);   // sets the pin as output
  pinMode(bpin, OUTPUT);   // sets the pin as output
}
 
void loop()                     // run over and over again
{
  unsigned char color[3] = {255, 0, 0    }; // start by red
  int s = 2; // bigger means faster fadind less smoother
  for (int c = 0; c < 6; ++c) { // go through the 6 colors
    for (int i = 0; i < 256-s; i += s) {
      color[0] += steps[c][0]*s;
      color[1] += steps[c][1]*s;
      color[2] += steps[c][2]*s;
      analogWrite(rpin, color[0]);
      analogWrite(gpin, color[1]);
      analogWrite(bpin, color[2]);
/*      int val = analogRead(pot_pin);
      val = (1024-val)/10;
      val = (val == 0) ? 1 : val;
      delay(val);
      */
      delay(10);
    }
  }
}