As a part of my next Physical Computing assignment (more on that later), I need to build a little module that will read the color of whatever it is pointed at. I’ve been using this site as a starting point, which is very helpful. What happens is that three LEDs - one red, one green and one blue - light up in sequence and the reflected light is measured by the photoresistor. Those three values can be combined into one RGB color which the computer can display. Pretty nifty!

In the example, they have a integrated circuit powering the cycle of the lights. I took a look at the documentation for the counter circuit we have in the lab and it was totally over my head, so I decided to use the Arduino to take care of the cycling. This limits how many color sensors I can have running in total, but the LEDs are pretty pricey, so it’s probably for the better.

My next steps with the color sensor are to calibrate the LEDs by getting their values against something white and something black. Then I should be able to map the values in the range of 0-255 and have Processing produce a color. I’m having problems with my Wordpress uploads permissions, so I will post pictures later.