[Xastir] GNGGA vs GPGGA support

[Jason KG4WSV]

Works on my uBlox CAM-M8. 

Thanks Tom!

-Jason


> On Apr 11, 2019, at 2:58 PM, Tom Russo <russo at bogodyn.org> wrote:
> 
> GNSS, GLONASS, Beidou, and Gallileo support is no on the main branch of
> the Xastir repo, no fork needed.  Update your clone, and you should be able
> to use Xastir with multi-constellation receivers now.  So far it has only been
> tested with GPS and GNSS receivers, but it should work with all the others.
> 
> If you try it and it doesn't work, please open a bug report on GitHub, and
> we'll run it to ground.
> 
> On Wed, Apr 10, 2019 at 10:56:38PM -0600, we recorded a bogon-computron collision of the <russo at bogodyn.org> flavor, containing:
>> Turns out that the GNGGA/GNRMC vs. GPGGA/GNGGA issue is the reason for
>> the newly opened issue #53 on github (https://github.com/Xastir/Xastir/issues/53), 
>> and I believe I have it fixed with pull request #58 (https://github.com/Xastir/Xastir/pull/58)
>> 
>> If any users with GLONASS receivers that emit GNGGA/GNRMC sentences (such
>> as the DRAWS hat for Raspberry Pi) would like to test it out, 
>> you can get it via:
>> 
>>   cd <your clone>
>>   git checkout master
>>   git checkout -b tvrusso-feature-supportglonass master
>>   git pull https://github.com/tvrusso/Xastir.git feature-supportglonass
>> 
>> Then rebuild Xastir and try it out.
>> 
>> The more folks I can get testing this the better.  I won't merge to master
>> until I at least confirm that it helps the GN vs. GP thing.  As far as I can
>> tell so far, I haven't borken it for GP.
>> 
>> On Sun, Dec 02, 2018 at 02:52:06PM -0600, we recorded a bogon-computron collision of the <kg4wsv at gmail.com> flavor, containing:
>>> I just started playing with a u-blox 8 family GPS.  It's capable of
>>> receiving multiple GNSS simultaneously. At first glance this unit doubles
>>> the number of available satellites just because it's listening to GLONASS
>>> and GPS at the same time.
>>> 
>>> Of course there's a downside. In APRS-land we're used to dealing with a
>>> single "talker ID" that indicates we're dealing with GPS (the name of the
>>> US system) - that's the "GP" in GPGGA and GPRMC. This system uses GN as the
>>> talker ID when it's listening to multiple systems.  I can configure it to
>>> use GPS only and get my familiar GPGGA, but I stop listening to a bunch of
>>> available satellites when I do that.
>>> 
>>> Since APRS has limited resolution we (APRS users) wouldn't benefit much
>>> from increased accuracy, but we would get something from having a much
>>> larger constellation available.
>>> 
>>> Has anyone messed with these multi-GNSS receivers? Are the benefits that
>>> seem obvious at first glance real?
>>> 
>>> Would it be appropriate to think about code changes to Xastir (or other
>>> clients but i don't use those) to use G[PLABN]GGA or G[PLABN]RMC instead of
>>> restricting ourselves to GP only? There would be 2 cases here, once for the
>>> attached GPS interface to determine our position, and the GPGGA APRS packet
>>> type.  I'm actually considering using GGA and RMC packets to get increased
>>> resolution on a non-144.39 tracking application.
>>> 
>>> Does xastir verify the NMEA checksum from an attached GPS?
>>> 
>>> -Jason
>>> kg4wsv
>>> _______________________________________________
>>> Xastir mailing list
>>> Xastir at lists.xastir.org
>>> http://xastir.org/mailman/listinfo/xastir
>> 
>> -- 
>> Tom Russo    KM5VY
>> Tijeras, NM  
>> 
>> echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z] [n-z][a-m]
> 
> -- 
> Tom Russo    KM5VY
> Tijeras, NM  
> 
> echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z] [n-z][a-m]
>