Re: [gpsd-users] Garmin 18X-5Hz

[Gary E. Miller]

Yo Frank!

On Fri, 12 Aug 2016 18:08:24 -0400
Frank Nicholas <address@hidden> wrote:

> > On Aug 12, 2016, at 4:04 PM, Gary E. Miller <address@hidden> wrote:
> > But the Uputronics uses an external antenna.  And has a battery
> > backup.  
> 
> The Adafruit Ultimate GPS (I think that’s what he’s talking about)

Yup.  Adafruit Ultimate GPS HAT

https://www.adafruit.com/products/2324

Versus the Uputronics:

https://store.uputronics.com/index.php?route=product/product&product_id=81

> has a connection for an external antenna

Ah, so it does, one of the nasty U.FL thingys.  Not like the proper 
SMA on the Uputronics.

> and comes with an optional
> battery backup (just for GPS state/system - no clock chip).

Ditto the Uputronics.

Adafruit claims there is an RTC, I've never got it to work, but not
tried hard.  Maybe someone will show me how.

The Uputronics comes with the header soldered in, so better for
non-soldering people.  The Uputronics header can also stack hats.

The Uputronics also comes with a u-blox 8 instead of the Mediatek M3339.
So it is a newer gen receiver.

The Uputronics has a 'stationary' mode, but i've never tried it.
Unlikely I could measure any improvement given Pi latency.

Compare these two scatter plots:

    https://pi2.rellim.com/pi2.png
    https://pi3.rellim.com/uputronics.png

I've rerun the Adafruit plot many times, always funcky like that.

I'll put an antenna on my Adafruit, that might help.

They both seem to work better than a Pi2 or Pi3 can keep time if there
is any load.

A lot of NTPsec people are using one, the other, or both.  This will
lead to ntpd improvements as many people can now see the current
issuss and are thinking of software improvements.

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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