[Merkaartor] Various GPS issues [PATCH]

[Travers Carter]

On Tue, 18 Aug 2009 12:31:19 +0200, Stefan Dirsch <sndirsch at suse.de> wrote:
> With merkaartor 0.14 (openSUSE 11.1 i586) I'm using gpsfake to feed NMEA
> data through gpsd. I observed various issues doing this.
> 
> - 'center on GPS' apparently works, but since the current position is not
>   marked graphically at all by Merkaartor you don't see exactly where you
>   are. :-( I believe I've seen a red circle around the current position
in
>   a
>   previous release of Merkaartor for this (not sure, maybe this was still
>   Merkaartor 0.12).
>
> - I'm wondering if the timestamps of the NMEA data is used or generated 
>   from the current time when the data is received from gpsd, since the
>   showed speed is definitely not correct.
> 

Hi,

I just noticed the issue with the graphical indicator missing too, I
believe
it used to work for me using a direct GPS connection, but it isn't working
now that I'm using gpsd, the attached patch against svn seems to get things
working for me with gpsd 2.39 (Fedora 11), it updates the parsing of the
"O=" gpsd line.

The marker issue seems to be a problem with Merkaartor not detecting that
there
is a position fix (at least when using gpsd), so it doesn't draw the
marker,
even though it does find the lat/lon.

The speed issue looks to be a unit conversion problem, according to the
gpsd
man page speed is reported in metres/sec, not the NMEA default of knots, 
with the patch the speed displayed by Merkaartor looks to match xgps so I
think I've got that bit right.


-- 
Travers Carter - Noggin - http://www.noggin.com.au/
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