>         Imagine as if they where two remote controls that you put "head
> to head"
> and communicate with each other.
>         So, I can4t use an optoisolator.

Okay.  That's a good answer.

>         If I connect an I.R emitter to one PIC, how do I connect the
> detector to
> the other one ?
>         I mean, supossing no interference (wich means no filtering), do
> I have to
> amplify the
> singal the detector receives ?

Err, well the answer is it depends.  I don't have your test equipment in
front of me, nor do I have the actual components or the design brief.

If the transmitter uses a modulated carrier to drive the IR led the you
could use one of the modules in the datasheet I indicated, or one of the
ones that Jinx mentioned.  These modules are easy to use, and give you a
clean TTL signal out.

If the transmitter is not modulated then you could use a photodiode or
phototransistor to detect the IR.  It is quite possible that you will
get sufficient signal level because the emitter is very close, and you
could perhaps just use a pullup resistor with your receiver.  If you
cannot get a clean signal this way you must build a more elaborate
circuit to successfully detect the IR signal.  I do not have any
examples of this I am afraid, but it is a common enough project to find
in textbooks or with Google (although most of the hits I got with Google
are using the ready made modules).  I suggest that you forget about the
PICs at the moment and work on the IR TX/RX pair.  You should be able to
turn the transmitter on and off and see the receiver respond correctly
(with an oscilloscope preferably).  When that is working, you can
connect the circuits to a PIC and fix the new problems you will encounter.

Andy

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu