int colourValue = 0;

int redPin = 9;
int grnPin = 10;
int bluPin = 11;

int redVal = 0;
int grnVal = 0;
int bluVal = 0;

const int numReadings = 10;
const int faderSampleRate = 10;

int readings[numReadings];
int readIndex = 0;
int total = 0;
int inputPin = A3;

void setup()
{
  pinMode(redPin, OUTPUT);
  pinMode(grnPin, OUTPUT);
  pinMode(bluPin, OUTPUT);
  Serial.begin(9600);

  for (int thisReading = 0; thisReading < numReadings; thisReading++) {
    readings[thisReading] = 0;
  }
}


void loop() {
  colourValue = map(constrain(analogRead(inputPin), 750, 1024), 750, 1024, 0, 1024);
  total = total - readings[readIndex];
  readings[readIndex] = colourValue;
  total = total + readings[readIndex];
  readIndex = readIndex + 1;
  if (readIndex >= numReadings) readIndex = 0;
  colourValue = total / numReadings;
  outputColour();
  delay(25);
}

void outputColour()
{
  if (colourValue < 341)  // Lowest third of the potentiometer's range (0-340)
  {
    colourValue = (colourValue * 3) / 4; // Normalize to 0-255

    redVal = 256 - colourValue;  // Red from full to off
    grnVal = colourValue;        // Green from off to full
    bluVal = 1;             // Blue off
  }
  else if (colourValue < 682) // Middle third of potentiometer's range (341-681)
  {
    colourValue = ( (colourValue-341) * 3) / 4; // Normalize to 0-255

    redVal = 1;            // Red off
    grnVal = 256 - colourValue; // Green from full to off
    bluVal = colourValue;       // Blue from off to full
  }
  else  // Upper third of potentiometer"s range (682-1023)
  {
    colourValue = ( (colourValue-683) * 3) / 4; // Normalize to 0-255

    redVal = colourValue;       // Red from off to full
    grnVal = 1;            // Green off
    bluVal = 256 - colourValue; // Blue from full to off
  }
  analogWrite(redPin, redVal);   // Write values to LED pins
  analogWrite(grnPin, grnVal);
  analogWrite(bluPin, bluVal);
}