// set up constants for input and output pins
const int redLEDPin = 9;
const int greenLEDPin = 10;
const int blueLEDPin = 11;

const int redSensorPin = A0;
const int greenSensorPin = A1;
const int blueSensorPin = A2;

// add variables for incoming sensor and output values
int redValue = 0;
int greenValue = 0;
int blueValue = 0;

int redSensorValue = 0;
int greenSensorValue = 0;
int blueSensorValue = 0;

void setup() {
    // begin communication at 9600bps
    Serial.begin(9600);

    // define LED pins as outputs
    pinMode(redLEDPin, OUTPUT);
    pinMode(greenLEDPin, OUTPUT);
    pinMode(blueLEDPin, OUTPUT);
}

void loop() {
    redSensorValue = analogRead(redSensorPin);
    delay(5);
    greenSensorValue = analogRead(greenSensorPin);
    delay(5);
    blueSensorValue = analogRead(blueSensorPin);

    // print out sensor values on one line
    Serial.print("Raw Sensor Values \t RED: ");
    Serial.print(redSensorValue);
    Serial.print("\t GREEN: ");
    Serial.print(greenSensorValue);
    Serial.print("\t BLUE ");
    Serial.print(blueSensorValue);

    // convert sensor reading from value between 0-1023 to value between 0-255
    redValue = redSensorValue / 4;
    greenValue = greenSensorValue / 4;
    blueValue = blueSensorValue / 4;

    // print mapped sensor values to serial monitor
    Serial.print("Mapped Sensor Values \t RED: ");
    Serial.print(redValue);
    Serial.print("\t GREEN: ");
    Serial.print(greenValue);
    Serial.print("\t BLUE: ");
    Serial.print(blueValue);

    // change LED's brightness via PWM 
    analogWrite(redLEDPin, redValue);
    analogWrite(greenLEDPin, greenValue);
    analogWrite(blueLEDPin, blueValue);
}