I have been playing with WB2OSZ Direwolf software, it is very powerful and can act as a APRS Touch Tone gateway. His software ia located HERE.
I was able to get his code working under windows and using the DTMF decoder it is decoding my 10 digit call sign and a two digit message. This is a new configuration idea suggested by the father of APRS WB4APR, see the new idea below. I just set mine up on a simplex radio for testing.
-----------Bob's new idea! --------------
But here is the NEW idea of how to use its 2 digit message capability
1) Have it listen from a very high central metro area location for DTMF on
2) The two-digit messages (01 to 99) can be used to trigger the APRS and
voice response of "CALLSIGN, LISTENING ON XXX.XXX MHz"
3) then ALL APRS mobiles in the area will see the message on their radios
4) AND he messages goes worldwide in the APRS-IS system
5) You could be called back via Echolink for example
6) AND if anyone is monitoring 146.58, they will hear EVERYONE on the air
and where they are listening.
In our area with over 50 repeaters, we are so spread out, hardly any
repeater is being used. But this way, everyone's "presence" on the air is
announced on APRS and the single 146.58 just like APRS was always intended
to be... a single clearing house channel for everything happening in ham
But now you only need a DTMF radio. Not a full APRS rig.
Oh, we just make a local list 01 to 99 of the different frequencies. Every
local list is different, but so are the repeaters in every local area...
Though I am starting to think it can be quite universal! Wow, Il start
now... for example 76 is 146.76 and 94 is 146.94, etc!
You just program your DTMF memory with the few repeaters you use, and then
sending out your message is just one button. Send the DTMF memory with
your chosen "monitoring frequency!
for more info on APRStt see http://aprs.org/aprstt.html
Bob Bruninga, WB4APR
USNA Satellite Lab