I'm in the process of defining the protocol to be used from some 'local=20
area' sensors to a PIC processor.  In short, this will be PIC-to-PIC=20
communication over a one-way optoisolated interface.

The sensors will be relatively dumb on the communication - that is,=20
they're just going to set there and read whatever they're reading, and=20
then emit a datastream basically consisting of 32 bits of sensor data,=20
repeated at a fairly high rate.   I'll probably add some sort of=20
checksum byte as well, etc...

Normally I'd just use fairly low-bitrate async serial for this, and I=20
may still end up back there, but the problem is that often I won't have=20
the luxury of a hardware async port for the receiver.   So I'd like to=20
make sure that whatever coding method I use, that it is fairly easy to=20
decode using either an interrupt-on-change type of routine or something=20
similar which doesn't take a lot of cycles on a fairly busy 'host'=20
PIC.    The actual bitrate can be relatively low - even a few hundred=20
bits/second should be fine.

I've been looking around and other than async, it looks like manchester=20
encoding might be an option, but I also wouldn't be surprised if i've=20
missed something else.

I'm asking this under the [PIC] tag as I am specifically hoping to find=20
something which is PIC-processor friendly.

Thanks.

-forrest
--=20
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