Welcome to my instructable!

The project I want to share with you today is Arduino Color Picker, a device that will let you pick any color from real life object(s) and display it in convenient way so you can use it for example in any drawing software, GUI web development and much more!

Step 1: Parts List

For this project we will need:

TCS34725 RGB Color Sensor For Arduino by DFRobot
I2C 16x2 Arduino LCD with RGB Font Display by DFRobot
DFRduino Pro Mini V1.3(8M3.3V328) by DFRobot
2 x CR2032 Battery Holders
Sliding switch
RGB LED module
Wires
3x7 cm prototyping PCB
Male and female pin header
2x M2x20 screws and nuts

Tools:

3D printer, if you don't own it, you can get printed case from Shapeways: click here
phillips screwdriver
soldering iron
solder

Step 2: Schematics

Refer to opening video's assembly section and schematic below to see how to place parts on a PCB.

Use schematic provided above for correct wiring.

Step 3: Design and 3D Print the Case

After we have measured the parts, it is time to design a 3D case and print it!

Design

Here is the link to my design on tinkercad: https://www.tinkercad.com/things/dG47Pr28uwx

Case above is designed to perfectly fit all the components listed above.

Front part will hold the LCD screen and color sensor.

Main 3x7 cm PCB will hold DFRDuino Pro Mini, battery holders and 3 push buttons and will be screwed on the back part from inside.

RGB LED will sit inside the top section of the back part.

Power switch will fit in the small hole on the back part.

Printing

3D models ready for printing are available on Thingiverse: https://www.thingiverse.com/thing:3223709

Print settings may vary depending on your printer.

Supports are needed for battery cover part and front part because front part has a built in distancer to provide distance between color sensor and specimen.

If you don't own a 3D printer, you can get printed case from Shapeways: click here

Assembly

For assembly instructions please refer to the assembly section of the video provided at the begining.

Step 4: Source Code

Source code is available for free on GitHub: https://github.com/alojzjakob/Arduino-Color-Picker

You are more than welcome to improve the code, as the code provided is only the starting point, but works well.

This project uses these 2 specific libraries, so make sure you add these to your Arduino IDE:

#include <DFRobot_TCS34725.h>
#include <DFRobot_LCD.h>
#define ledPin 12
#define redpin 3
#define greenpin 5
#define bluepin 6
const int8_t button1Pin = 7; //1
const int8_t button2Pin = 8; //2
const int8_t button3Pin = 9; //3
int8_t button1State = 0;
int8_t button2State = 0;
int8_t button3State = 0;
#define ACTIVATED LOW
// for a common anode LED, connect the common pin to +5V
// for common cathode, connect the common to ground
// set to false if using a common cathode LED
#define commonAnode true
// our RGB -> eye-recognized gamma color
byte gammatable[256];
DFRobot_LCD lcd(16,2);
DFRobot_TCS34725 tcs = DFRobot_TCS34725(0x50, TCS34725_GAIN_60X);
bool ledEnabled=false;
int lightsMode=0;
// make some custom characters:
byte light_on[8] = {
    0b00100,
    0b00100,
    0b01110,
    0b11111,
    0b11111,
    0b01110,
    0b00000,
    0b10101
};
byte light_off[8] = {
    0b00100,
    0b00100,
    0b01110,
    0b10001,
    0b10001,
    0b01110,
    0b00000,
    0b00000
};
byte rgb_on[8] = {
    0b00000,
    0b10101,
    0b00000,
    0b01110,
    0b01110,
    0b01110,
    0b11111,
    0b11111
};
byte rgb_off[8] = {
    0b00000,
    0b00000,
    0b00000,
    0b01110,
    0b01010,
    0b01010,
    0b10001,
    0b11111
};
void setup() {
  lcd.init();
  // create a new character
  lcd.customSymbol(0, light_on);
  lcd.customSymbol(1, light_off);
  lcd.customSymbol(2, rgb_on);
  lcd.customSymbol(3, rgb_off);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  pinMode(button1Pin, INPUT);
  pinMode(button2Pin, INPUT);
  pinMode(button3Pin, INPUT);
  
  digitalWrite(button1Pin, HIGH);
  digitalWrite(button2Pin, HIGH);
  digitalWrite(button3Pin, HIGH);
  
  pinMode(redpin, OUTPUT);
  pinMode(greenpin, OUTPUT);
  pinMode(bluepin, OUTPUT);
  analogWrite(redpin,0);
  analogWrite(greenpin,0);
  analogWrite(bluepin,0);
  
  // thanks PhilB for this gamma table! it helps convert RGB colors to what humans see
  for (int i=0; i<256; i++) {
    float x = i;
    x /= 255;
    x = pow(x, 2.5);
    x *= 255;      
    if (commonAnode) {
      gammatable[i] = 255 - x;
    } else {
      gammatable[i] = x;      
    }
  }
  
}
void loop() {
  button1State = digitalRead(button1Pin);
  button2State = digitalRead(button2Pin);
  button3State = digitalRead(button3Pin);
  int btn=0;
  if(button1State==LOW){
    btn=1;
  }
  if(button2State==LOW){
    btn=2;
  }
  if(button3State==LOW){
    btn=3;
    lightsMode++;
    if(lightsMode==4){
      lightsMode=0;
    }
  }
  
  
  
  uint16_t clear, red, green, blue;
  tcs.getRGBC(&red, &green, &blue, &clear);
  // Figure out some basic hex code for visualization
  uint32_t sum = clear;
  float r, g, b;
  r = red; r /= sum;
  g = green; g /= sum;
  b = blue; b /= sum;
  r *= 255; g *= 255; b *= 255;
  String redHex,greenHex,blueHex;
  redHex =  String((int)r, HEX);  
  greenHex =  String((int)g, HEX);  
  blueHex =  String((int)b, HEX);  
  lcd.setRGB(r,g,b); //Set lcd backlight RGB Value
  lcd.setCursor(0,0); // print values on lcd
  lcd.print("#"); lcd.print(redHex); lcd.print(greenHex); lcd.print(blueHex); lcd.print("   ");
  lcd.setCursor(0,1);
  lcd.print("rgb(");
  lcd.print((int)r); lcd.print(",");
  lcd.print((int)g); lcd.print(",");
  lcd.print((int)b); lcd.print(")       ");
  
  
  if(lightsMode==0){
    ledEnabled=false;
    lcd.setCursor(15,0);
    lcd.write((unsigned char)1);//light off
    lcd.setCursor(14,0);
    lcd.write((unsigned char)2);//rgb led on
    //Set the color of RGB led indicator
    analogWrite(redpin, round(gammatable[(int)r]/4));
    analogWrite(greenpin, round(gammatable[(int)g]/4));
    analogWrite(bluepin, round(gammatable[(int)b]/4));
  }
  if(lightsMode==1){
    ledEnabled=true;
    lcd.setCursor(15,0);
    lcd.write((unsigned char)0);//light on
    lcd.setCursor(14,0);
    lcd.write((unsigned char)2);//rgb led on
    //Set the color of RGB led indicator
    analogWrite(redpin, round(gammatable[(int)r]/4));
    analogWrite(greenpin, round(gammatable[(int)g]/4));
    analogWrite(bluepin, round(gammatable[(int)b]/4));
  }
  if(lightsMode==2){
    ledEnabled=true;
    lcd.setCursor(15,0);
    lcd.write((unsigned char)0);//light on
    lcd.setCursor(14,0);
    lcd.write((unsigned char)3);//rgb led off
    //Set the color of RGB led indicator
    analogWrite(redpin, 255);
    analogWrite(greenpin, 255);
    analogWrite(bluepin, 255);
  }
  if(lightsMode==3){
    ledEnabled=false;
    lcd.setCursor(15,0);
    lcd.write((unsigned char)1);//light off
    lcd.setCursor(14,0);
    lcd.write((unsigned char)3);//rgb led off
    //Set the color of RGB led indicator
    analogWrite(redpin, 255);
    analogWrite(greenpin, 255);
    analogWrite(bluepin, 255);
  }
  if(ledEnabled){
    digitalWrite(ledPin, HIGH);  
  }else{
    digitalWrite(ledPin, LOW);  
  }
  
  //delay(10);
}

Step 5: Enjoy Your New Tool + Improvement Plans

Now you can go around and pick some nice colors :)

Currently only the 3rd button is used to cycle through lights as shown in the video.

Plan for near future is to implement functionality for other buttons:

button 1 should pick a color and store it in memory so you can cycle through last 10 colors
button 2 will bring up menu, containing color picker history and much more!
- if in menu mode button 1 acts as select, button 3 will act as back/escape

I hope you enjoyed this tutorial and will have fun using this color picker!