Re: [gpsd-users] GL* strings and gpspipe

[Gary E. Miller]

Yo John!

On Mon, 14 Jan 2019 22:33:32 +0000
John Klug <address@hidden> wrote:

> We want to use the u-blox gpsd driver so our patch for leap second
> will work.

Uh, lost me, why would you do that?  We know of nothing related to
leapseconds that should be changed, just the opposite.

> So if gpspipe is to put out NMEA strings

Which is bad assumtpion. gpspipe knows nothing of NMEA, it just passes
on what it gets.

> (or maybe both u-blox and
> nmea), should we use gpsctl to configure the u-blox for both u-blox
> and nmea combined?

Unrelated.  No matter whether the GPS is in NMEA or binary mode, you
will always get (psuedo) NMEA with 'gpspipe -r'.

gpsctl only configures the u-blox from binary to NMEA and back.  Not
both.  That is unrelated to what you tell gpspipe to do with gpsd.

To do both, which is pointless as all the data in the NMEA is also in
the binary.  To force the GPS to emit both binary and NMEA you would
need to do something special, like modify ubxtool or preset the GPS.

But that is pointless duplication.  Or worse.

> I believe it is possible for it to write both.

If by 'it' you mean gpspipe, then only with 'gpspipe -R' with the GPS
prgrammed to do both.  Possible, but not useful.

> Then we could use gpspipe -r, and get both?

No.  if you program the GPS to do both, then you would do 'gpspipe -R' to
get both, but in that case there is no need for gpsd any more.

> Or would that cause gpsd to fail,

Nope, pointless, but gpsd can handle it, gpsd just passes on what it
gets.

> or would gpsd clear out the settings by gpsctl to use both
> NMEA and u-blox proprietary?

gpsctl calls gpsd, not the other way around.  Once gpsd is running it
will not reconfigure the GPS unless told to do so.

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

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