Re: How to get raw data from gpsd?

[Gary E. Miller]

Yo 张延涛!

On Mon, 1 Apr 2024 19:04:57 +0800
张延涛 <zh6tao@gmail.com> wrote:

> > Can you get me documentation on the binary protocol?  
> 
> I'm sorry, we are unable to obtain the protocol documentation from
> the GNSS chip manufacturer as well.

That will be a problem.  I did find a little documentation.

https://docs.datagnss.com/rtk-board/files/datasheet/01_Module/Common%20command/T-5-2010-Common%20Commands%20Exclusive%20to%20Allystar-V1.0.pdf

https://docs.datagnss.com/rtk-board/files/T-5-1908-001-GNSS_Protocol_Specification-V2.3.pdf

> In our current operations, we
> only need to provide an interface to the chip manufacturer, enabling
> them to retrieve raw data through this interface.

The you do not need gpsd.

> Once the chip
> manufacturer receives the raw data, the specific parsing rules are
> left to them to handle. *It would be great if you could add an
> interface to gpsd that allows for the retrieval of completely raw
> data!*

Not going to happen.  The point of gpsd is to filter out junk,
when autobauding there is a very large amount of junk.  With no
documentation, your data stream looks the same as junk.

However, with the above doc, I did add a skeleton ALLYSTAR driver to git
head.  And found out your data stream is junk.  Most, but not all, of the
ALLYSTAR messages have bad checksums.  Enough are good that I know my
skeleton driver is working.

> > Can you build gpsd from git head and test?  
> 
> Yes, I can compile gpsd from the git head and write test programs.

Then please grab a copy of the current git head and see how that
works for you.

> >  Do you have sample parts you can send me?  
> 
> Regarding your request for sample parts, raw data is essentially a
> black box for us as well. Therefore, we don't have any samples to
> provide for your reference.

If I have parts, I can figure out the black box, and I have enough doc
to decode most messages.  You help me, I help you.

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

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