Re: -GPSD 3.22 autobauding under bullsEye

[Gary E. Miller]

Yo Don!

On Mon, 13 Dec 2021 21:03:24 -0500
Don Rolph <don.rolph@gmail.com> wrote:

> One can certainly do better and cheaper for GPS units, but for a GPS
> unit at a reasonable price within the PI Zero form factor, this
> appeared to be among the cheapest.

Your choice, cheap, or good.  Uputronics and sparkfun and not much more
expensive, and way better.  Or for cheaper than the Adafruit you can get
a better GPS on a break board.

For $25, you can get a u-blox M8030 like this:

https://www.ebay.com/itm/284328934112?hash=item4233533ae0%3Ag%3AUd0AAOSwhKpgwzIe&LH_BIN=1

Smaller, cheaper, better.  Should be half that price, but, inflation
and supply chain issues...

> This is part of a stack of boards based on the PI Zero W or PI Zero 2
> W. The emissions from the PI Zero, USB WIFI chip, and USB hub
> preclude the GPS board from making a fix.

Many have done that, you are the first to report any issue.

> This is easily
> demonstrated by experiment. Having the GPS board far removed from the
> stack results in a rapid fix. Placing the GPS board at the top of the
> stack results in never getting a fix.  Introducing the aluminum foil
> shield between the GPS board and the rest of the stack now allows fix
> to be achieved. Making the foil larger and slightly curved causes the
> GPS to achieve fix in typically seconds.

Sounds more like you are adding a ground plane that increases the
sensitivity of the MT333x.  If it works for you, then great.

> If I want to fit within the PI Zero form factor, the foil shield must
> be smaller and hence has less impact on the speed of achieving a fix.

And no chance for an external antenna?

> And for this version of the  project I have to fit in app[oxiately
> the PI Zero W form factor.  Other versions of this project typically
> use a GPS puck unit which does not have this problem.

Of course pucks have their own issues.

> Actually I can't ignore SIRF:  for the application the standard
> equipment presently used uses the SirF chip:  if I exceed SIRF chip
> performance then this is better than the present solution.

Good luck buying SiRF chips in the future.  Easy to beat something you
can't buy.


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

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