[aprssig] indoor tracking.

Robert Bruninga bruninga at usna.edu
Mon May 30 22:10:50 EDT 2005

Here is what I would do that should cost peanuts
yet track everyone indoors that carries one.  A
GREAT club project:

A match box sized PIC that you clip on your hat.
It transmits nothing but your CALLSIGN using
an IR diode.

In the center of a room, we have little IR receivers
connected to a pocket-tracker transmitter.
Whenever a CALLSIGN walks underneath,
the special pocket tracker in the ceiling
transmits an APRS RF packet using that
persons callsign with a 100' position ambiguity.

With the 100 foot ambiguity, then up to 9
callsigns could be separately resolved in
that area.  Actually the PIC would serially
assign the last 9 calls heard to the 9
nearest 60' resolved positions so that
there was no overlap.  (APRS resolves
LAT/LONG to the nearest 60 feet)

To save power, the cap-mounted user transmitter
could have an IR receiver looking for a special
signal from the room-IR-digi and would not
waste power transmitting the IR except when
it saw the interrogation from the IR-digi.

All this would take is a little PIC code in the
Pocket Trackers to make the special
ROOM-DIGIS and a super simple
PIC and 9v battery to make the cap-mounted
IR user systems.

These would be GREAT club projects for everyone
to build their own CAP mounted IR transmitter.
In fact, I would imagine a small solar panel
about 3" square could easily power it.

If every club brought a ROOM-DIGI with them
and every club member wore a CAP-IR tracker
then this would be fun at any place that HAMS

Bob, Wb4APR

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