Re: [gpsd-dev] implementing $GPVTG -- how should I interperet ', , , , ' fields?

[teyrana]

Got it. Thanks! 

Daniel Williams

address@hidden

858-220-8134 (Mobile)
github.com/teyrana
LinkedIn

On Wed, May 16, 2018 at 12:54 PM, Gary E. Miller <address@hidden> wrote:

Yo teyrana!

On Wed, 16 May 2018 12:16:54 -0400
teyrana <address@hidden> wrote:

> Should empty fields (",," in NMEA 0183) be interpreted as missing, or
> zero?

Missing.

> I'm testing our $GPVTG patch, and it breaks 1 / 113 tests.

Pretty common for new patches.

> The line in question is near the top of
> 'test/daemon/gp-320fw-2019-04-07-coldboot.log.chk', at line 80:
> "$GPVTG,,T,,M,2C"  (Those double commas correspond to the velocity and
> course fields.)
>
> So, this generates the line:
> '+{"class":"TPV","mode":2,"track":0.0000,"speed":0.000}'
>
> While this is not very surprising...  is it expected / desired
> behavior?

Unwanted behavior.  No data is no data.  No data is not zero.

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

            Veritas liberabit vos. -- Quid est veritas?
    "If you can’t measure it, you can’t improve it." - Lord Kelvin