Re: [gpsd-dev] [RFC] $GPVTG & magnetic course

[teyrana]

> I've not look at that code, so take care that users of compass_variation

> can tell good from bad data in that field.

Are you referring to "users" internal to gpsd (like the struct -> json code)? or client applications? ...

This made me curious, so I grepped the codebase (yes, the entire codebase) ...

> grep -Rn -e compass_variation   *.c

gps.h:1853:    double compass_variation;

... (plus my addition).  Does this match your experience?

Do you have any external projects in mind, that we should check with?

Daniel Williams

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On Wed, May 30, 2018 at 6:45 PM, Gary E. Miller <address@hidden> wrote:

Yo teyrana!

On Wed, 30 May 2018 18:39:09 -0400
teyrana <address@hidden> wrote:

> Another idea for extract the $GPVTG message data was to stored the
> compass variation in existing variables, like so:
>
> > session->gpsdata.navdata.compass_variation = true_track -
> > mag_track; 
>
> Yay or nay?

Yeah, that works.  Just remember some other sentence may also supply
in that data item.  Presumably they would match.

I've not look at that code, so take care that users of compass_variation
can tell good from bad data in taht feild.

RGDS
GARY
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