// Set up the rgb led names
uint8_t ledR = 2;
uint8_t ledG = 4;
uint8_t ledB = 5; 

uint8_t ledArray[3] = {1, 2, 3}; // three led channels

const boolean invert = true; // set true if common anode, false if common cathode

uint8_t color = 0;          // a value from 0 to 255 representing the hue
uint32_t R, G, B;           // the Red Green and Blue color components
uint8_t brightness = 255;  // 255 is maximum brightness, but can be changed.  Might need 256 for common anode to fully turn off.

// the setup routine runs once when you press reset:
void setup() 
{            
  Serial.begin(115200);
  delay(10); 
  
  ledcAttachPin(ledR, 1); // assign RGB led pins to channels
  ledcAttachPin(ledG, 2);
  ledcAttachPin(ledB, 3);
  
  // Initialize channels 
  // channels 0-15, resolution 1-16 bits, freq limits depend on resolution
  // ledcSetup(uint8_t channel, uint32_t freq, uint8_t resolution_bits);
  ledcSetup(1, 12000, 8); // 12 kHz PWM, 8-bit resolution
  ledcSetup(2, 12000, 8);
  ledcSetup(3, 12000, 8);
}

// void loop runs over and over again
void loop() 
{
  Serial.println("Send all LEDs a 255 and wait 2 seconds.");
  // If your RGB LED turns off instead of on here you should check if the LED is common anode or cathode.
  // If it doesn't fully turn off and is common anode try using 256.
  ledcWrite(1, 255);
  ledcWrite(2, 255);
  ledcWrite(3, 255);
  delay(2000);
  Serial.println("Send all LEDs a 0 and wait 2 seconds.");
  ledcWrite(1, 0);
  ledcWrite(2, 0);
  ledcWrite(3, 0);
  delay(2000);
 
  Serial.println("Starting color fade loop.");
  
 for (color = 0; color < 255; color++) { // Slew through the color spectrum

  hueToRGB(color, brightness);  // call function to convert hue to RGB

  // write the RGB values to the pins
  ledcWrite(1, R); // write red component to channel 1, etc.
  ledcWrite(2, G);   
  ledcWrite(3, B); 
 
  delay(100); // full cycle of rgb over 256 colors takes 26 seconds
 }
 
}

// Courtesy http://www.instructables.com/id/How-to-Use-an-RGB-LED/?ALLSTEPS
// function to convert a color to its Red, Green, and Blue components.

void hueToRGB(uint8_t hue, uint8_t brightness)
{
    uint16_t scaledHue = (hue * 6);
    uint8_t segment = scaledHue / 256; // segment 0 to 5 around the
                                            // color wheel
    uint16_t segmentOffset =
      scaledHue - (segment * 256); // position within the segment

    uint8_t complement = 0;
    uint16_t prev = (brightness * ( 255 -  segmentOffset)) / 256;
    uint16_t next = (brightness *  segmentOffset) / 256;

    if(invert)
    {
      brightness = 255 - brightness;
      complement = 255;
      prev = 255 - prev;
      next = 255 - next;
    }

    switch(segment ) {
    case 0:      // red
        R = brightness;
        G = next;
        B = complement;
    break;
    case 1:     // yellow
        R = prev;
        G = brightness;
        B = complement;
    break;
    case 2:     // green
        R = complement;
        G = brightness;
        B = next;
    break;
    case 3:    // cyan
        R = complement;
        G = prev;
        B = brightness;
    break;
    case 4:    // blue
        R = next;
        G = complement;
        B = brightness;
    break;
   case 5:      // magenta
    default:
        R = brightness;
        G = complement;
        B = prev;
    break;
    }
}