FLARM NMEA sentences questions

[Marco Zonca]

Hello,

on T-Echo I turned on Flarm nmea sentences output via bluetooth, they looks excellent, so I started to work on a project about a small hardware to produce sound alarms.

Looking in detail it looks there is a repetition for the last 3 data fields near the end of $PFLAA sentences (see the attached picture below): "...0,0,-99,0,0,-99*67".

Additionally I see every some seconds, independently from presence of surrounding aircrafts or not, the $PSRFH sentences I do not know and I did not found something about it searching around. Do you know the meaning of the data fields inside it?

The 1st field is 5605A6=myID, the 2nd could be 7=paraglider, the 7th could be 845=myAltitude in feet, but  the others I have no idea.

Thank you.

[Moshe Braner]

For the fields in the PFLAA sentence see the FLARM documentation.  After the ID come:

course, empty field, speed, climb_rate, aircraft_type, no_track, data_source, rssi.  The additional repeat of the last 3 fields should not be there, but I now see that in the T-Echo (not the T-Beam) it is coming from the "PFLAA_EXT1_ARGS".  I'll fix that in the next version.

The PSRFH sentence (once in 10 seconds) is my own invention of a SoftRF "heartbeat".  The fields are:

ThisAircraft_id, rf_protocol, millis(), (int)(battery_voltage*100), getFreeHeap(), rx_packets_counter, tx_packets_counter, number_of_aircraft, max_rssi

[Marco Zonca]

Hello,

MB158 (T-Echo) nmea PFLAU sentence got one "," comma too much at the end of the packet when no ID present as per following example:

$PFLAU,0,1,1,1,0,,0,,,,*63
$PFLAU,1,1,1,1,0,140,0,705,4226,111177*4B

So, the first sentence got 11 fields, the second one got 10 fields. I did a workaround on my software.

[Moshe Braner]

Thanks Marco.  Will fix that in a future version.