infrared proximity transceiver suggestion for basic stamp

henry99

I'm trying to make my own optical encoder and need a series of reflective transmitter/receiver packages that can work with the basic stamp (preferably with minimal signal conditioning).

Any suggestions for an infrared transmitter/receiver pair that has filtering for sunlight/ambient noise?· Thanks in advance.

Mike Green

I don't think you're going to find a simple IR transmitter (LED)·/ receiver (phototransistor)·pair that's got some filtering for ambient light unless you go to modulated IR and that doesn't have a superfast response time (because of the filtering).· Still, I think that the 38KHz detectors that Parallax uses will respond in about 8-10 cycles which is well under a millisecond.· They won't respond to 60Hz or 120Hz and they're fairly robust in sunlight, particularly if you use simple shielding from direct sunlight.

henry99

I've been researching it and was wondering if anyone had experience with something like a Sharp GP2Y0D340K (http://www.hobbyengineering.com/SectionS.html)?

Can I paint my wheel black and white and it will detect the white but not the black spots?

I want to put alternating stripes of black and white on a wheel and detect the rotation speed. I want high accuracy, 1 degree or better and the wheel rotates at around 60Hz.

Any suggestions? Thanks again for the help.

Franklin

http://www.acroname.com/robotics/parts/R64-P5587.html

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- Stephen

henry99

Thanks for the suggestion on the p5587. It doesn't list the range in the specs though. I need .5-1 inch or so. Most IR pairs I've seen are only good for 2mm max. At that range, I'd just use a hall effect sensor which is more robust. I've seen some induction sensors that are good to 12mm. Any other IR pair suggestions?