[aprssig] 434 MHz tracker

Robert Bruninga bruninga at usna.edu
Fri Dec 19 12:38:59 EST 2008


> I revisited an old project tonight.
> 434 MHz TX and GPS, easy radio module.
> Sending: 
>  
> VK4TEC-12>APRS,WIDE: <<UI>>:=2734.45S/15306.21E'SATS 03
> RAW,27344551,S,153062152,E
>  
> Takes 76 ms on busy pin, or 44 ms of actual data.
> The down side is the power out is only low, mW

Actually that is perfect!  And all you need to send is:

"VK4TEC"

Which drops it to 4ms of data.  AND then the RECEIVING device
which is located at the door of the clubhouse, EOC, ham radio
store, local bar, church, jail and everywhere else in town where
hams might be found adds the following info:

LAT/LONG
SYMBOL for RFID tag
Local RF Voice Channel at that location
Comments about that location

And then sends that packet out on the APRS channel like this:

VK4TEC-12>APRS,WIDE1-1:=2734.45S/15306.21E'147.105MHz AARC Radio
Clubhouse

But the hundredths digit of LATITUDE is randomized so that
everyone at that location will appear as a list at that location
and not all on top of each other.

Please see the APRS RFID web page:
http://www.aprs.org/aprs-rfid.html

Put this in a Key Fob and all a Ham has to do  is push a button
and he instantly is seen globally, whwere he is, what he is
doing, and what frquency to contact him on.

Go for it!
Bob, Wb4APR





More information about the aprssig mailing list