Adam meyer

//Configure gain here
//Higher numbers = less sencitive
// 0x00 through 0x0f
int redGain = 0x03;
int greenGain = 0x0;
int blueGain = 0x0f;
int clearGain = 0x01;

//RGB LED pins
//Digital PWM pins
int redPin = 9;
int greenPin = 10;
int bluePin = 11;



//Include the I2C Arduino library
#include <Wire.h>

//7 bit I2C address of this sensor
#define I2C_ADDRESS 0x74

#define REG_CAP_RED		0x06
#define REG_CAP_GREEN	 0x07
#define REG_CAP_BLUE	 0x08
#define REG_CAP_CLEAR	 0x09

#define REG_INT_RED_LO	0x0A
#define REG_INT_RED_HI	0x0B
#define REG_INT_GREEN_LO 0x0C
#define REG_INT_GREEN_HI 0x0D
#define REG_INT_BLUE_LO	0x0E
#define REG_INT_BLUE_HI	0x0F
#define REG_INT_CLEAR_LO 0x10
#define REG_INT_CLEAR_HI 0x11

#define REG_DATA_RED_LO	0x40
#define REG_DATA_RED_HI	0x41
#define REG_DATA_GREEN_LO 0x42
#define REG_DATA_GREEN_HI 0x43
#define REG_DATA_BLUE_LO 0x44
#define REG_DATA_BLUE_HI 0x45
#define REG_DATA_CLEAR_LO 0x46
#define REG_DATA_CLEAR_HI 0x47

float redFactor=1;
float blueFactor=1;
float greenFactor=1;

//initial darkLevel;
int calibrationDarkness = 0;
byte calibrationRed = 5;
byte calibrationGreen = 5;
byte calibrationBlue = 5;


void setup(void){
	Serial.begin(9600);
	Wire.begin();

	// sensor gain setting (Avago app note 5330)
	// CAPs are 4bit (higher value will result in lower output)
	set_register(REG_CAP_RED, redGain);
	set_register(REG_CAP_GREEN, greenGain);
	set_register(REG_CAP_BLUE, blueGain);
	set_register(REG_CAP_CLEAR, clearGain);

	int ledGain = getColorGain();

	set_gain(REG_INT_RED_LO,ledGain);
	set_gain(REG_INT_GREEN_LO,ledGain);
	set_gain(REG_INT_BLUE_LO,ledGain);

	performMeasurement();

	int red=get_readout(REG_DATA_RED_LO);
	int green=get_readout(REG_DATA_GREEN_LO);
	int blue=get_readout(REG_DATA_BLUE_LO);

	int m=2000; //bigger anyway
	m=min(m,red);
	m=min(m,green);
	m=min(m,blue);

	//Serial.print("m - ");
	//Serial.println(m);

	redFactor=((float)m*255.0)/(1000*(float)red);
	greenFactor=((float)m*255.0)/(1000*(float)green);
	blueFactor=((float)m*255.0)/(1000*(float)blue);


}

void loop() { 

	int clearGain = getClearGain();
	set_gain(REG_INT_CLEAR_LO,clearGain);
	int colorGain = getColorGain();
	set_gain(REG_INT_RED_LO,colorGain);
	set_gain(REG_INT_GREEN_LO,colorGain);
	set_gain(REG_INT_BLUE_LO,colorGain);


	//reset the RGB (and clear) values
	int cc = 0;
	int red=0;
	int green=0;
	int blue=0;


	// Take 4 samples, and add them together.
	for (int i=0; i<4 ;i ++) {
		performMeasurement();
		cc +=get_readout(REG_DATA_CLEAR_LO);
		red +=get_readout(REG_DATA_RED_LO);
		green +=get_readout(REG_DATA_GREEN_LO);
		blue +=get_readout(REG_DATA_BLUE_LO);
	}

	//now, divide the totals for each by 4 to get their average.
	cc/=4;
	red /=4;
	green /=4;
	blue /=4;

	//take the values mesured from above, and multiply them with the factors to
	//find out what value should be sent to the external RGB LED to reproduce this color
	float redValue = (float)red*redFactor;
	float greenValue = (float)green*greenFactor;
	float blueValue = (float)blue*blueFactor;


	Serial.print("red: ");
	Serial.print(redValue);

	Serial.print("green: ");
	Serial.print(greenValue);

	Serial.print("blue: ");
	Serial.print(blueValue);


	//send to LED
	analogWrite(redPin, map(redValue, 0, 1024, 0, 255));
	analogWrite(greenPin, map(greenValue, 0, 1024, 0, 255));
	analogWrite(bluePin, map(blueValue, 0, 1024, 0, 255));	


	//hold it for one second
	delay(1000); 
}

int getClearGain() {
	int gainFound = 0;
	int upperBox=4096;
	int lowerBox = 0;
	int half;

	while (!gainFound) {
		half = ((upperBox-lowerBox)/2)+lowerBox;


		if (half == lowerBox) { //no further halfing possbile
			break; //no further halfing possbile
		} 
		else {
			set_gain(REG_INT_CLEAR_LO,half);
			performMeasurement();
			int halfValue = get_readout(REG_DATA_CLEAR_LO);

			if (halfValue > 1000) {
				upperBox=half;
			} 
			else if (halfValue<1000) {
				lowerBox = half;
			} 
			else {
				break; //no further halfing possbile
			}
		}
	}
	return half;
}

int getColorGain() {
	int gainFound = 0;
	int upperBox=4096;
	int lowerBox = 0;
	int half;
	while (!gainFound) {
		half = ((upperBox-lowerBox)/2)+lowerBox;

		if (half==lowerBox) { //no further halfing possbile
			break; // gain found
		} 
		else {

			set_gain(REG_INT_RED_LO,half);
			set_gain(REG_INT_GREEN_LO,half);
			set_gain(REG_INT_BLUE_LO,half);
			performMeasurement();
			int halfValue = 0;

			halfValue=max(halfValue,get_readout(REG_DATA_RED_LO));
			halfValue=max(halfValue,get_readout(REG_DATA_GREEN_LO));
			halfValue=max(halfValue,get_readout(REG_DATA_BLUE_LO));

			if (halfValue>1000) {
				upperBox=half;

			} 
			else if (halfValue<1000) {
				lowerBox=half;

			} 
			else {
				break; // gain found
			}
		}
	}
	return half;
}


void performMeasurement() {
	set_register(0x00,0x01); // start sensing

	while(read_register(0x00) != 0) {
		// waiting for a result
	}
}

int get_readout(int readRegister) {
	return read_register(readRegister) + (read_register(readRegister+1)<<8);
}

void set_gain(int gainRegister, int gain) {
	if (gain <4096) {
		uint8_t hi = gain >> 8;
		uint8_t lo = gain;

		set_register(gainRegister, lo);
		set_register(gainRegister+1, hi);
	}
}

void set_register(unsigned char r, unsigned char v){

	Wire.beginTransmission(I2C_ADDRESS);
	Wire.send(r);
	Wire.send(v);
	Wire.endTransmission();
}

unsigned char read_register(unsigned char r){

	unsigned char v;
	Wire.beginTransmission(I2C_ADDRESS);
	Wire.send(r); // register to read
	Wire.endTransmission();

	Wire.requestFrom(I2C_ADDRESS, 1); // read a byte
	while(!Wire.available()) {
		// waiting
	}
	v = Wire.receive();
	return v;
}

//Configure gain here
//Higher numbers = less sencitive
// 0x00 through 0x0f
int redGain = 0x02;
int greenGain = 0x2;
int blueGain = 0x02;
int clearGain = 0x02;

//function takes 0-100 to light up LED 0 to 100%

int bluePin = 11;
float blueVolts = 3.2;

void writeBlue(int power){
  float maxPower = (255/5) * blueVolts;
  int output = map(power, 0, 100, 0, maxPower);
  analogWrite(bluePin, output);
}

writeBlue(75); //blue LED at 75% power