>We built a system for doing what you describe a few years back. The ti
transponders looked quite good, however the receivers were a little
expensive. I would go with the ti >system if you have a large number of
trucks.
>The transponders are good if
>(1) You have a large number of trucks per receiver, or
>(2) The mobile units do not have their own power. or
>(3) The transponders are not moving past the receiver too quickly.

>A simple alternative to the transponders is to simply send a dumb dtmf
tone through a H field. This gives you 16 distinct 'trucks' and then use a
cheap tone decoder chip on a >receiver (with a dumb loop pickup).
>Otherwise use a cheap, say, 27MHz low power Tx/Rx pair (Don't be afraid to
use walkie talkies, an excellent robot book I say some time ago had that
idea for robot comms).

>Adam Crow
>Crowtech Pty Ltd
>www.ozemail.com.au/~crowtech

>P.S. Others may be interested in this post, could you post it to the PIC
list please?

Sure!

Octavio
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Octavio Nogueira
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