Code Deep Dive: Data & Math

Now let's look at the data the robot uses to identify colors and the clever math that makes it work.

4. The Reference Chart (Color Values)

This is the robot's cheat sheet. When it sees a gem, it compares the detected RGB values to this list and finds the closest match:

1Color colors[] = {
2  { "Pink", 255, 148, 145, 145 },
3  { "Blue", 144, 237, 255, 126 },
4  { "Red", 255, 82, 72, 72 },
5  { "Orange", 255, 145, 72, 90 },
6  { "Green", 130, 255, 150, 108 },
7  { "Blank", 255, 171, 125, -1 }
8};

5. Fine Tuning (Calibration)

Robots aren't perfect out of the box. Sometimes a motor is slightly crooked, or we need it to move slower.

1short int TopServoOffset = 0;
2short int SlideServoOffset = 0;
3
4int collectDelay = 800;
5int moveDelay = 1000;
6int topDelay = 500;

6. The Math (Color Distance)

This is the smartest part of the code! How does the robot know if the color it sees is closer to "Red" or "Pink"? It uses 3D geometry!

float calculateDistance(uint16_t r1, uint16_t g1, uint16_t b1, 
                        uint16_t r2, uint16_t g2, uint16_t b2) {
  return sqrt(pow(r2 - r1, 2) + pow(g2 - g1, 2) + pow(b2 - b1, 2));
}

Try It Yourself

Use the sliders below to "detect" a color and watch how the robot calculates the distance to each stored color. The closest match determines where the slide moves!