Re: gpsd issue #53 forwarding: UBX8 batched mode operation (super-e Mode) support

[Gary E. Miller]

Yo Quentin!

On Thu, 30 Jan 2020 14:59:10 +0100
Quentin Cabrol <address@hidden> wrote:

> The thing is, in this mode, the GNSS modem will send no data at all
> (no periodic frame) This bit of code in gpsd.c causes a disconnection
> when entering this mode (proper configuration with ubxtool):

email mangled your code...

Also, can you confirm the options you used to start gpsd?  I assume you
used the "-n" option?

> I ran some tests and commenting the *detach_client()* call after the
> buffer length check is performed yields the expected behavior. But I
> am not sure how exactly gpsd.c could be modified to account for the
> use case without impacting the normal operation.

I see no good reason for the detach_client() call.  It may explain some
problems I have seen in the past.  OTOH, detach_client() is used many
other places, so a more general look needs to be taken at the issue.

Does anyone have an argument for keeping detach client in gpsd.c on line
2456?

> Also, in the driver_ubx, parsing of the frame is not supported yet. I
> made an initial proposal for parsing the UBX-LOG-BATCH frames pushing
> the parsed data to the "newdata" structure (current data) but as
> commented by Gary, BATCHED data is in fact a log of older data and
> not the current data per say.  So this is incorrect to do so and
> LOG-BATCH data should not be parsed by updating the newdata structure.

At least not where you did put it.  Not sure yet where it should go.

> 
>  =====================
> 
> Used ubxtool configuration script for the ZOE-M8B EVK:

Email mangled it pretty badly.  Almost impossible to read.  Best to
attach scripts so they don't get mangled.

I'm confused why you did not use more of the canned commands?  The
script is WAY longer than it needs to be.  That needs to be a seperate
discussion.

> Example of LOG-BATCH frame decoded by ubxtool

We need a raw binary capture.  This is useless.  Something like the
output of:
        gpspipe -R -n 30 > log.raw

> *Quentin Cabrol*
> Aeler Technologies SA

If this is a corporate project, please consider ways to pay back the
gpsd project for all the work it is saving your company.

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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    "If you can't measure it, you can't improve it." - Lord Kelvin

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