Project Challenge - Building a Color Sensor!

We [Simple Labs] are planning to throw out a challenge at the growing student community of arduino users in india. The challenge is to build a color sensor that can sense a color and output the same using a RGB LED. Wondering if we should make it even more challenging by adding in the need for a closed loop system (measure the output color as well!)... However I have my doubts - Will we be able to sense color from an RGB LED like we can sense light reflected of different colors?

All thoughts and ideas to improvise this challenge are welcome. no solutions please :wink:

Cheers,
Pracas

Will we be able to sense color from an RGB LED like we can sense light reflected of different colors?

Think the light is definitely different as a LED peaks in three wavelengths and the light of the sun is "broadband". Further you need somthing to diffuse it (sugarcube?)

How do you intend to measure the different colors? a special device ? - Color Light Sensor - Avago ADJD-S371-Q999 - SEN-08618 - SparkFun Electronics - or three LDR's with a filterglass. The latter offers more room for experimentation as they can use anything semi-transparant as colorfilter, or include polaroid filters.

The closed loop is interesting if you program a delay in it and 'rotate' the colors (red->yellow->blue->red) or so.

sofar my 2 cents,

However I have my doubts - Will we be able to sense color from an RGB LED like we can sense light reflected of different colors?

Not easily - lots of diffusion required and reflected light from an object depends on the light source - the LED produces its own light...

Perhaps you could have a colour calibrated printer to print the sensed colour.

Here is the link to the event posting on Facebook