http://www.piclist.com would likely be a good place to start. There are
more than a few ways to generate a Manchester encoded stream from a PIC.
Perhaps if you gave some more detail of the particular PIC (feature set)
you are planning to use and more information about your requirements, we
could give some better advice as to how to proceed.
I am getting some TWS-434 and RWS-434 RF modules in the mail soon and
I understand from some preliminary web searches that something called
"Manchester encoding" is required to make RF links reliable.
I will do a little testing when I get the modules to see how reliable
they are without Manchester encoding. Hopefully I will be able to get
along without it.
I want a radio link for a small robot, data rates in the 5 bytes per
second range. I am familiar with both the 16F and 18F families of
On Thu, 06 May 2004 14:34:03 GMT, "Anthony Fremont"
Hi ron -- I've used these units, and you'll definitely want to use
Manchester encoding -- the performance will be significantly better than
Fortunately, Manchester encoding is pretty trivial to implement. For a
description, see the following URL:
All Manchester encoding really involves on the sending side is to send
each bit followed by its complement. So a logical 1 is encoded as 1 0. A
logical 0 is encoded as 0 1. Manchester encoding the start bit is
optional, but recommended.
When sampling the RWS output on the receiving end, expect each data bit
to be followed by its complement. So a 0 followed by a 1 is a logical 0.
A l followed by a 0 is a 1. If you see a 1 1 or 0 0, you have an error.
That's really all there is to it. You should see a major improvement in
range using this method, since the receiver circuitry is most sensitive
to transitions in the incoming signal. Both reliability and range will
be improved greatly.
Hope that helps -- tAfkaks
(reply to mikey at swampgas dot com -- ignore the spamtrap Reply-To)
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