Re: Q about "Stratum-1-Microserver HOWTO"

[Gary E. Miller]

Yo All!

Mark, thanks for the forward.

More inline, below.

On Sat, 16 May 2020 11:46:37 -0700
"Mark Atwood" <address@hidden> wrote:

> I am forwarding to Eric and Gary.  Feel free to ask them questions
> directly about GPS stuff.
> 
> 
> ----- Original message -----
> From: Wis Macomson <address@hidden>
> To: address@hidden
> Subject: Q about "Stratum-1-Microserver HOWTO"
> Date: Tuesday, May 05, 2020 11:23
> 
> Mark,
> 
> Rather than bug ESR directly, I'm assuming this is the proper channel
> to initiate contact. He's welcome to contact me directly, of course.

gpsd users <address@hidden>" is a good place for
requests like this,  Then others that you do not know the name of can
share the load for Eric and I.

I have included them in my reply.  Subscribe there to continue the
conversation.  That list includes many others in your position.

> Regarding the "Stratum-1-Microserver HOWTO": if the GPS unit supports
> a fixed position mode to improve timing accuracy, is it possible to
> write the command to the GPS via the serial port?

Yup.  Of course, that is very dependant on the GNSS receiver you
are using.

> It seems likely;
> thepossible hitch could be that GPSD gets confused with an unexpected
> response to the command.

Nope.

> If so, can  the command be issued before
> GPSD starts, or does GPSD clean the GPS receiver's house on startup,
> to guarantee known state?

Sort of, it depends.  Without knowing the receiver model, no way to
say.

> To be clear, the Uputronics HAT with the UBlox receiver claims to
> have the "timing mode" command.

Still not specific enough.  There are several versions of that HAT.

easy to tell, while gpsd is running, issue this command:

$ ubxtool -p MON-VER

It will reply with the stuff coming from the receiver, and something
like this:

[...]
UBX-MON-VER:
  swVersion 2.01 (75331)
  hwVersion 00080000
  extension PROTVER 15.00
  extension GPS;SBAS;GLO;BDS;QZSS
[...]

That tells us what your receiver is, if it is a u-blox.

> As background, I plan to put this thing together soon - RPI4 and GPS
> are on order. I'll be using the current "Buster Lite" Linux on the
> RPI (Note: Amazon is really slow on delivery these days - I take
> issue with what they deem "essential items".)

IMHO, Raspbian is better than Buster on RasPi.

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

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