Color Sensor Demystified
When [millerman4487] bought a TCS230-based color sensor, he was expecting a bit more documentation. Since he didn’t get it, he did a little research and some experimentation and wrote it up to help the rest of us.
The TCS3200 uses an 8×8 array of photodiodes. The 64 diodes come in four groups of 16. One group has a blue filter, one has green and the other has a red filter. The final set of diodes has no filter at all. You can select which group of diodes is active at any given time.
Sixteen photodiodes have blue filters, 16 photodiodes have green filters, 16 photodiodes have red filters, and 16 photodiodes are clear with no filters. The four types (colors) of photodiodes are interdigitated to minimize the effect of non-uniformity of incident irradiance. All photodiodes of the same color are connected in parallel. Pins S2 and S3 are used to select which group of photodiodes (red, green, blue, clear) are active.
The output of the array is a frequency that corresponds to the light intensity measured by one bank of photodiodes. You’ll need to make several pulse input measurements to compute the color and [millernam4487] provides code for it. You may, however, need to calibrate the device before you get good results.
We’ve looked at color sensors before, of course. They can even unlock doors.
[original story: Hack a Day]