RGB_Colorwheel.ino

int redPin = 3;
int greenPin = 5;
int bluePin = 6;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
  setLedColor(255,0,0);
}

void loop() {
  for (int i = 0; i < 360; i++){
    setColorByHue(i);
    delay(10); 
  }
  
}

void setColorByHue(int angle){
  if (0 <= angle && angle < 120){
    int red = map(angle, 0, 120, 255, 0);
    int green = map(angle, 0, 120, 0, 255);
    int blue = 0;
    setLedColor(red, green, blue);
  }
  else if (120 <= angle && angle < 240){
    int red = 0;
    int green = map(angle, 120, 240, 255, 0);
    int blue = map(angle, 120, 240, 0, 255);
    setLedColor(red, green, blue);
  }
  else{ //angle between 240 and 360
    int blue = map(angle, 240, 360, 255, 0);
    int red = map(angle, 240, 360, 0, 255);
    int green = 0;
    setLedColor(red, green, blue);
  }
}

void setLedColor(int r, int g, int b){
  analogWrite(redPin, r);
  analogWrite(greenPin, g);
  analogWrite(bluePin, b);
}

void setLedColor(int colorVector[]){
  setLedColor(colorVector[0], colorVector[1], colorVector[2]);
}