Colour sensor?

[Arislan]

http://www.lynxmotion.com/images/html/proj050.htm

I'm a bit confused by the above robot. Can someone explain how it can see colours? I don't see a camera attached to the robot.

[JesseWelling]

I see that he has 3 trim pots and I'm guessing that's to tune the input from a wavelength specific photoresistor of some sort. maybe you could use celophane covered photoresistors....never really heard of it but.....

[JesseWelling]

http://www.taosinc.com/
Just found this here : http://www.societyofrobots.com/robot_parts_list_sensors.shtml

[dunk]

if you have a look here: http://www.lynxmotion.com/images/jpg/color.jpg you will get the idea.
it is illuminating the m&m with different colours of light.
switch on the different colours of led, one at a time and
a red m&m will reflect back more red light,
a blue one will reflect back more blue light,
etc.

dunk.

[Arislan]

Thanks! I hadn't realised the meaning of "cds" on the schematic. This explains the meaning:
http://www.robotroom.com/ColorSensor.html

It looks like that researcher got a lot of good photoresistors for a bargain :S Unfortunately I moved to Brazil recently and nothing here is cheap.

[Admin]

ive been thinkin of making a color sensor tutorial for awhile now . . . and not just for visible light . . .

what dunk said is the cheapest/easiest way . . .

the taos sensors are for only a single color, so you would need multiple of those designed for different colors . . . those are higher precision, meaning they work great for telling the difference between shades of colors.