Hi,

I have been folowing the discussion about IR Programable Remote, It is
interesting how similiar the design that some peaple on this list
suggested is similar to my design. It works well, it can recieve in
comming IR signal and regenerate it.

- instead of using an IR module, you should better use a IR led with an
  amplifier that would trigger the PIC.

> On a PIC you will have to have a few K (2K) of external RAM to hold
> the samples before analysis

I do it with alot less ram. number of samples will not fill that much
memory, BUT, it need to be fast access memory (parallel SRAM).

> and a 1K or 2K EEPROM to hold the resulting values for all the commands,

This depends on how you want to save data and what you want to do with the
recieved IR commands, if it only to do an action then you do not need to
save it. If you need to retransmit it then again you would probably not
need to save it.

> but the program will be a tight fit on a
> 16C84. Whether analysis should only find the end of the IR command
> sequence and remove the carrier and store the demodulated signal
> or try to reduce it further is up to the programmer and the available
> program/data space.

I am using 16C74 at 20MHz. 16MHz was not fast enoght for some of the
things I do.

> During playback one might let the PIC handle the modulation, since
> you will at least be able to vary the modulation to a certain
> degree (your accuracy will improve with CPU speed, but so your
> current consumption will go up). This has been done and if the
> receiver you transmit to is flexible enough, neither of you will miss
> the 555.

I do the modulation using one of the PWM modules, but, for this you need
to know the carrier frequency.

> I've never implemented raw IR capture on a PIC (and I don't intend to),
> but I've done it on PCs and Amigas and it does work. PIC capture of
> totally unknown remotes without IR receiver/demodulators can
> probably be done, but I've never seen the need in my applications.

It works well for me.

Chaipi

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! Chaipi Wijnbergen                                                           !
! Electronics/Computer Eng. M.Sc.  Tel    : +972-8-9343079                    !
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