I'd like to do a manual calibration for brightness and compare it to the automatic version. Since the analogRead function yields a 10 bit value at 4.9mV per unit it's possible to calculate what resistor needs to be place on each color in order to calibrate them with physical resistors and then not need the Arduino to calculate the relative values.
http://www.youtube.com/watch?v=QmNnJd9drYs
int redPin = 9; // LED connected to digital pin 9
int greenPin = 11;
int bluePin = 10;
int pins[] =
{
redPin, greenPin, bluePin
};
int photoPin = 0;
int redPot = 1;
int greenPot = 2;
int bluePot = 3;
int photoVal = -1;
int rr, gg, bb = -1;
int minmax, rmax, gmax, bmax = 0;
void setup() {
Serial.begin(9600);
Serial.println("Start");
pinMode(redPin, OUTPUT);
pinMode(greenPin, OUTPUT);
pinMode(bluePin, OUTPUT);
digitalWrite(redPin, HIGH);
digitalWrite(greenPin, HIGH);
digitalWrite(bluePin, HIGH);
digitalWrite(redPin, LOW);
delay(500);
rmax = analogRead(photoPin);
digitalWrite(redPin, HIGH);
digitalWrite(greenPin, LOW);
delay(500);
gmax = analogRead(photoPin);
digitalWrite(greenPin, HIGH);
digitalWrite(bluePin, LOW);
delay(500);
bmax = analogRead(photoPin);
digitalWrite(bluePin, HIGH);
sendMax();
minmax = min(rmax, min(gmax, bmax));
setRGB(255, 255, 255);
}
void setRGB(int red, int green, int blue)
{
//These values are the 10 bit values, they need to be mapped to minmax
//For some reason some values were mapping negative
red = map(red, 0, 1023, 0, minmax);
green = map(green, 0, 1023, 0, minmax);
blue = map(blue, 0, 1023, 0, minmax);
sendRGB(red, green, blue);
red = map(red, 0, minmax, 255, 0);
green = map(green, 0, minmax, 255, 0);
blue = map(blue, 0, minmax, 255, 0);
analogWrite(redPin, red);
analogWrite(greenPin, green);
analogWrite(bluePin, blue);
sendRGB(red, green, blue);
}
void sendRGB(int red, int green, int blue)
{
Serial.print(" { \"red\" : ");
Serial.print(red);
Serial.print(", \"green\" : ");
Serial.print(green);
Serial.print(", \"blue\" : ");
Serial.print(blue);
Serial.print("}");
}
void sendMax()
{
Serial.print(" { \"rmax\" : ");
Serial.print(rmax);
Serial.print(", \"gmax\" : ");
Serial.print(gmax);
Serial.print(", \"bmax\" : ");
Serial.print(bmax);
Serial.println("}");
}
void loop()
{
rr = analogRead(redPot);
gg = analogRead(greenPot);
bb = analogRead(bluePot);
setRGB(rr, gg, bb);
sendRGB(rr, gg, bb);
Serial.print(" { \"minmax\" : ");
Serial.print(minmax);
Serial.println("}");
}
