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Re: Using RCX light sensor with NXT

Posted: 27 Jan 2011, 20:54
by dsjove
I'll spend the time tonight to do a more thorough investigation.
The environment has inconsistent lighting. The light sensor is used to detect a passing train. What code and/or bricks do you recommend when using an RCX light sensor in such an open environment?

Re: Using RCX light sensor with NXT

Posted: 27 Jan 2011, 21:19
by h-g-t
Have you seen this device using fibre optic cables to take the light output from the led and shine it back towards the detector?

http://www.philohome.com/lightbarrier/lightbarrier.htm

I suppose you could use two cables, one to duct the light from the led and the other to funnel it back to the detector.

Or even this one which I just found :-

http://www.ben.com/LEGO/rcx/train-sensor.html

Re: Using RCX light sensor with NXT

Posted: 02 Feb 2011, 03:29
by dsjove
It is a low-light problem. As soon as I turn off most ambient lights, the sensor doesn't read well. Thoughts?

Re: Using RCX light sensor with NXT

Posted: 02 Feb 2011, 06:52
by mightor
dsjove wrote:It is a low-light problem. As soon as I turn off most ambient lights, the sensor doesn't read well. Thoughts?
I have one! Don't turn off the ambient lights.

"Doctor, it hurts when I press here."
"Well, stop pressing on it then."

If this is a sensor without a light of its own then you need the ambient light to make it work. If the little light isn't strong enough to bounce off the object you wish to detect (or not close enough), move it closer. If you can't, then you're out of luck or use another sensor.

- Xander

Re: Using RCX light sensor with NXT

Posted: 02 Feb 2011, 13:33
by dsjove
mightor wrote:I have one! Don't turn off the ambient lights.
I saw that one coming :D

I have two. They are studded, small, and have easily extended cables. I'll leave the ambient lights on. And in the mean time, I'll move it closer to the track.

Thank you.