Re: Strange troubles with emulation

[Gary E. Miller]

Yo Владимир!

On Sat, 30 Jan 2021 18:43:00 +0300
Владимир Калачихин <v.kalachikhin@gmail.com> wrote:

> 30.01.2021 01:36, Gary E. Miller пишет:
> > 
> > A recevier reporting Dead Reckoning would fail.  If taht case came
> > up, that would then need a special case on the special care.  That
> > is how driver_nmea0183 became little but special cases.
> >   
> 
> But why not just ignore bad sentences?

gpsd does that.  That is what you are complaining about.

But bad not the same as inconsistent.

> >>> Easier to fix your GGA, set sats used to 4.  One line of sed could
> >>> do that.  
> >>
> >> Should it be understood that gpsd ignore checksum?  
> > 
> > Nope, you would have to also fix the checksum.  But that is easy.  
> 
> Heh. The gpsbabel sets count of satellites on GGA sentence to 00
> string in principle:
> https://www.gpsbabel.org/htmldoc-development/fmt_nmea.html I do not
> know why this is so.

File a complaint with them.  Should be empty.

> I updated my log player to add a number of satellites to the GGA 
> sentence on the fly. With recalculate checksum, of course.
> Well, logs, created by gpsbabel, played smoothly.

Good. But I'm still confused why you do not fix the originals.

> But I confused:

I'm always confused.

> This
> https://gpsd.io/NMEA.html#_gga_global_positioning_system_fix_data
> approved that number of satellites are a string of two digits. I
> write one digit by mistake -- and gpsd accept this.

gpsd does not care about leading zeros.  NMEA explicitly allows leading
and trailing zeros in numeric fields.

> I think this is correct, but perhaps you will think otherwise.

If what I thought mattered, NMEA would be something very different.
I'm stuck with what real receivers send out.  Some evern try to stick
to the standard.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  Tel:+1 541 382 8588

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    "If you can't measure it, you can't improve it." - Lord Kelvin

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