Needed - wireless transceiver module for north american operation. I have
control over both ends, so most any protocol is reasonably possible
(Bluetooth, zigbee, wifi, etc) Likely a 16bit micro on both ends.
Functionally I need bi-directional control and status information on the
order of 100 bytes a second, desired latency under 50mS.
Minimum range of 100 feet line of sight. (practical operating range 30-50
feet)
Unit cost not too-too critical $50 ea ok, $20 ea better.
Relatively small, has to fit into a hand held device about the size of a
DMM.
Integrated antenna desirable.
Power requirements not constraining - other parts of the system use 10's of
watts, shaving milliwats here somewhat pointless.
Immediate demand perhaps 100 units, if all goes well, may need to scale up
to 1000 units a year.

(This next bit is the difficult part)

I need a way to measure the distance between two operating modules.
I'm thinking I can get a reasonable approximation from signal strength - so
I would need to be able to read signal strength information at least.
Other option I'm chewing on is time of flight. It's at least theoretically
possible to query remote module and measure the time from query to
response. Any digital signal processing is going to take vastly more time
than the signal takes to travel, so this may be challenging :-) I have some
thoughts, but this would be vastly easier if there were some supporting
functions in the radio module.

-Denny
--=20
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