Mike Harrison wrote:
> Wifi would probably overkill for this - a more appropriate way may be
> low cost sensor/transmitters on one of the unlicensed UHF bands sending
> short packets every few minutes to one or more receivers, depending on
> distance - the receiver could either be a PC or a data concentrator
> that bulks up the data to send via wifi/GSM/GPRS etc.

That's actually what our WiFi gizmo is a receiver for.  Normally the
receivers are connected to wired ethernet, but they want to have a WiFi
option.  The real job of the gizmo is to receive periodic transmissions from
up to a few 100 little transmitters scattered about.  These use 434MHz in
the ISM band, and run for well over a year on two button cells.  The
existing full featured tags have a 16F630 in them, and the new single-use
version they just came out with has a 10F202 controlling it, so you can see
it's not that complicated.


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