Hi there,
I am in the process of creating a prototype for a final year project at uni and i'm an Arduino newbie, I was hoping to pull RGB colour values received by an Avago ADJD-S371 colour sensor and send them to processing where a script would allow the user to simply paint on a white canvas with the colour that is being picked up by the colour sensor.
So far I have managed to get the ADJD-S371 hooked up to an arduino with the r,g and b values being picked up by the serial read in arduino software using the following code :
//Configure gain here
//Higher numbers = less sensitive
// 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);
Serial.println();
delay(200);
//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(500);
}
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;
}
However, i'm stuck when it comes to sending the serial read to processing and writing the code used in processing in order to create a paintbrush that changes colour with the RGB values received by the colour sensor.
Any help would be greatly appreciated!
Alex
