Hi Marcel,
I would use these modules, but for this project apart from detecting the
signal, I need to be able to measure signal magnitude to let me know if
I am close or far from the TX. This is not a remote control project.
Best regards 
		Luis  


-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf
Of Marcel duchamp
Sent: 23 June 2006 17:54
To: Microcontroller discussion list - Public.
Subject: Re: [EE] IR photodiode or phototransistor

Luis Moreira wrote:
> Hi Marcel,
> Do they actually use special IR detectors or the photodiode used is a
> normal one?
> At least is good to know about the limitations... I managed a range of
> about 3 meters and I thought it was a bit poor, obviously not...
> Best regards
> 		Luis

Both types are made - wide-band and narrow-band.  In general, you 
probably want the narrowest type that will work for you.  That helps 
with SNR by not being sensitive to out-of-band signals.

One of the big challenges with receiver design is obtaining high gain 
but not being saturated by ambient light.  This is another reason the 
modules use the carrier method and AC coupling.

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