Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: corrado33 on April 21, 2010, 08:07:10 PM
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So I have a learning remote control that doesn't work that well anymore. I want to use the IR LED in it to act as an IR receiver, then use another IR led to act as a emitter. Yep, you got it, I'm trying to build an IR range finder (more like an IR wall detector). Anyone know anything about Learning remote control IR LEDs?
Yes I will eventually buy IR rangefinders for my bot, but for now, I have no money, and I want to see if I can figure this one out.
EDIT: If you don't know what a learning remote control does... well, you push a learn button, then use another remote control to emit the frequency you want, then whatever button you tell the learning remote to use that frequency for, it will.
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Those LEDs are normal IR leds :)
They can be configured to sense IR light - search for LED as a light sensor.
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Those LEDs are normal IR leds :)
They can be configured to sense IR light - search for LED as a light sensor.
Yeah I've seen that done before, and in fact I was doing that a few seconds ago. I saw this video...
LEDs as sensors! (http://www.youtube.com/watch?v=fi1RGJZvBlk&feature=related#)
and if you look in the description it says the leds are switched from forward bias (normal hookup i think), reverse bias (acts as capacitor) and discharging (??????) I'm not sure what that last state is? Is that when you'd measure the voltage?
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I actually made it to a state science fair with this kind of stuff :)
Basically, reverse voltage the LED for 1 microsecond, end the reverse voltage, and measure the voltage coming out of the LED(from its capacitance), and time the time it takes to reach a certain point. That time varies depending on the incoming light.
See:
http://www.merl.com/projects/LEDcomm/ (http://www.merl.com/projects/LEDcomm/)