[aprssig] APRS: IoT via Ham Radio (-> telemetry format)

[Heikki Hannikainen]

On Wed, 20 Nov 2019, Jason KG4WSV wrote:

> APRS could simply act as a transport for MQTT messages as wb2osz points out at the beginning of this thread.
> 
> If the APRS telemetry source makes full use of the PARM/UNIT/EQNS/BITS features it would be relatively
> simple to put together an APRS to MQTT gateway that translates APRS telemetry packets to fully functional
> MQTT messages.  Likewise some MQTT messages could translate to APRS telemetry.

At this point I'd like to briefly highlight this fine proposal from 
Kenneth, under the title "Proposed Telemetry format":

https://github.com/PhirePhly/aprs_notes/blob/master/telemetry_format.md

It basically would relax the archaic APRS telemetry format of 8-bit 
integer values, to allow floating-point values and negative values too, 
without weird exercises with EQNS.

I think this would ease up the work of APRS implementations a lot, 
especially on the transmitting side. The network has an awful lot of 
trackers which send the 8-bit intneger values but the EQNS have never been 
sent, or they've been sent a few times 4 years ago.

Changes on receiving side would be trivial (just parse the floating-point 
values, and apply EQNS if they are available).

   - Hessu