[CART360] IR emitter/photodetector.

[Vincent Leclerc]

On 10/11/07, Marcos da Silva <marcosilva at videotron.ca> wrote:
> Hello,
> I'm trying to get information on the web about how the IR
> emitter/photodetector work.
> I'm wondering if they could be usefull in this mid-term concept. Would
> you know where I could find basic information about how they work. Is it
> as simple as applying voltage, (1.9V maybe), onto the emitter and the IR
> photodetector placed in front of it would receive the signal and send
> voltage out through its wires as a result?

It is as simple as that actually. Send 1.9V in the IR emitter and make
a voltage divider with the photodetector like this:

5V <---> Photodetector <- * -> 10K resistor <---> GND

And measure the voltage with an analog pin of the arduino between the
photodetector and the 10K resistor (where the * is). Keep in mind that
photodectors also have a polarity (like LEDs), so if it doesn't work
one way, try the other way.

Vincent