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STARTER KIT - COLOR MIXING LAMP

Arduino Starter Kit example
Project 4 - Color Mixing Lamp

This sketch is written to accompany Project 3 in the
Arduino Starter Kit

Parts required:
1 RGB LED
three 10 kilohm resistors
3 220 ohm resistors
3 photoresistors
red green and blue colored gels

Created 13 September 2012
Modified 14 November 2012
by Scott Fitzgerald
Thanks to Federico Vanzati for improvements

This example code is part of the public domain

const int greenLEDPin = 9;    // LED connected to digital pin 9
const int redLEDPin = 10;     // LED connected to digital pin 10
const int blueLEDPin = 11;    // LED connected to digital pin 11

const int redSensorPin = A0;  // pin with the photoresistor with the red gel
const int greenSensorPin = A1;   // pin with the photoresistor with the green gel
const int blueSensorPin = A2;   // pin with the photoresistor with the blue gel

int redValue = 0; // value to write to the red LED
int greenValue = 0; // value to write to the green LED
int blueValue = 0; // value to write to the blue LED

int redSensorValue = 0; // variable to hold the value from the red sensor
int greenSensorValue = 0; // variable to hold the value from the green sensor
int blueSensorValue = 0; // variable to hold the value from the blue sensor

void setup() {
  // initialize serial communications at 9600 bps:
  Serial.begin(9600);

  // set the digital pins as outputs
  pinMode(greenLEDPin, OUTPUT);
  pinMode(redLEDPin, OUTPUT);
  pinMode(blueLEDPin, OUTPUT);
}

void loop() {
  // Read the sensors first:

  // read the value from the red-filtered photoresistor:
  redSensorValue = analogRead(redSensorPin);
  // give the ADC a moment to settle
  delay(5);
  // read the value from the green-filtered photoresistor:
  greenSensorValue = analogRead(greenSensorPin);
  // give the ADC a moment to settle
  delay(5);
  // read the value from the blue-filtered photoresistor:
  blueSensorValue = analogRead(blueSensorPin);

  // print out the values to the serial monitor
  Serial.print("raw sensor Values \t red: ");
  Serial.print(redSensorValue);
  Serial.print("\t green: ");
  Serial.print(greenSensorValue);
  Serial.print("\t Blue: ");
  Serial.println(blueSensorValue);

  /*
  In order to use the values from the sensor for the LED,
  you need to do some math. The ADC provides a 10-bit number,
  but analogWrite() uses 8 bits. You'll want to divide your
  sensor readings by 4 to keep them in range of the output.
  */
  redValue = redSensorValue / 4;
  greenValue = greenSensorValue / 4;
  blueValue = blueSensorValue / 4;

  //  print out the mapped values
  Serial.print("Mapped sensor Values \t red: ");
  Serial.print(redValue);
  Serial.print("\t green: ");
  Serial.print(greenValue);
  Serial.print("\t Blue: ");
  Serial.println(blueValue);

  /*
  Now that you have a usable value, it's time to PWM the LED.
  */
  analogWrite(redLEDPin, redValue);
  analogWrite(greenLEDPin, greenValue);
  analogWrite(blueLEDPin, blueValue);
}