RGB Sensing

I have a project where the input will be from a RGB LED - it can be Green, Red or Blinking Red.

I need a quick and cheap sensor to read and differentiate between the three possible states. Is there a way to use a simple Photo cell (CdS photoresistor -http://www.adafruit.com/products/161 OR http://www.adafruit.com/products/1384) to differentiate between RGB?

I know i can use the RGB Color sensor but the project is quite cost sensitive for now. (http://www.adafruit.com/products/1334)


How about 2 or 3 ldrs connected to analog inputs?


Put colour filters of some kind in front of them. Then a bit of experimentation to determine the levels detected by each ldr for each of the rgb led colours.


You could use a paper hole punch to make small discs of the filter material and glue them to the ldrs.

This looks workable, any idea where I can get the color filters?

Sorry, just updated my reply!

Thanks, I am going to try this and get back to you