colorMixing.ino

// color mixing with common cathode rgb led
const int rPin = 4;
const int gPin = 3;
const int bPin = 2;

// value to increment/decrement
int rDir = 1;
int gDir = -1;
int bDir = -1;

// inital color vals
int rVal = 1;
int gVal = 127;
int bVal = 254;

void setup() {
  // set the pinmodes
  pinMode(rPin, OUTPUT);
  pinMode(gPin, OUTPUT);
  pinMode(bPin, OUTPUT);

  // check the colors
  colorTest();

}

void loop() {

  // write the color values
  analogWrite(rPin, rVal);
  analogWrite(gPin, gVal);
  analogWrite(bPin, bVal);

  // check if the brightness has reached upper or lower limit
  // if so, reverse direction
  if (rVal <= 0 || rVal >= 255) rDir = -rDir;
  if (gVal <= 0 || gVal >= 255) gDir = -gDir;
  if (bVal <= 0 || bVal >= 255) bDir = -bDir;

  // increment or decrement values
  rVal += rDir;
  gVal += gDir;
  bVal += bDir;

  // slight delay
  delay(15);
}

void colorTest() {
  analogWrite(rPin, 255);
  delay(250);
  analogWrite(rPin, 0);
  analogWrite(gPin, 255);
  delay(250);
  analogWrite(bPin, 255);
  analogWrite(gPin, 0);
  delay(250);
  analogWrite(rPin, 0);
  analogWrite(gPin, 255);
  analogWrite(bPin, 255);
  delay(250);
  analogWrite(rPin, 255);
  analogWrite(gPin, 255);
  analogWrite(bPin, 0);
  delay(250);
  analogWrite(rPin, 255);
  analogWrite(gPin, 0);
  analogWrite(bPin, 255);
  delay(250);

}

rgbLED.md