[Xastir] GNGGA vs GPGGA support

[Tom Russo]

I should point out that these updates only refer to handling of attached
location receivers, and do not add support for raw NMEA posits as Jason
had suggested.  It should not be super difficult to add that support, but
it isn't done yet.

On Thu, Apr 11, 2019 at 01:58:30PM -0600, we recorded a bogon-computron collision of the <russo at bogodyn.org> flavor, containing:
> 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]

-- 
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]