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Re: [gpsd-dev] Modifying (severly) hardware.html
From: |
Eric S. Raymond |
Subject: |
Re: [gpsd-dev] Modifying (severly) hardware.html |
Date: |
Mon, 13 Apr 2015 15:18:28 -0400 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
Hal Murray <address@hidden>:
> address@hidden said:
> > The current: http://www.catb.org/gpsd/hardware.html is good, if you have a
> > model in mind. Not so good if you are asking "What should I buy that is
> > supported?"
>
> If that's the question, I think the format of the answer would be a short
> list of known to work well devices and/or devices to beware of, probably
> focusing on the chips.
>
> This is what I would say if somebody asked me "What should I get?"
>
> SiRF 3 is good but poor for timing without PPS. (100 ms wander)
>
> SiRF 4 doesn't work well in binary mode. Is it OK in NMEA mode?
>
> The uBlox chips are good. (I think.)
>
> The Garmin 18x is OK. Same PPS/wander problem as SiRF.
>
> The xxx chip on the Sure board is good. (Needs soldering to get PPS.)
>
> The ???? chip on the Adafruit GPS hat works OK.
>
>
> PPS over USB works and is often much better than no PPS but not as good as
> PPS via a real serial port or GPIO. (Has anybody tried a printer port
> recently?)
>
> Older devices are much less sensitive. Modern devices often work well enough
> indoors where older chips frequently drop out.
That's a good start. I would modify as follows:
The SiRF IV has very poor weak-signal performance. I would not
recommend it unless you are certain you will always have a clear
skyview.
The uBlox chips are *excellent*. If there were a readily available
consumer-grade uBlox-based device I would recommend nothing else.
(The Sure board uses an engine called a SKG16B which is otherwise unattested.
The Adafruit hat has a Venus 6 in it.)
In 2015, sadly, your best bat for a packaged GPS is to find a remaindered
SiRF-III. But you almost certainly won't get PPS out of it.
--
<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>
- [gpsd-dev] Modifying (severly) hardware.html, Sanjeev Gupta, 2015/04/13
- Re: [gpsd-dev] Modifying (severly) hardware.html, Eric S. Raymond, 2015/04/13
- Re: [gpsd-dev] Modifying (severly) hardware.html, Hal Murray, 2015/04/13
- Re: [gpsd-dev] Modifying (severly) hardware.html,
Eric S. Raymond <=
- Re: [gpsd-dev] Modifying (severly) hardware.html, Hal Murray, 2015/04/15
- Re: [gpsd-dev] Modifying (severly) hardware.html, Eric S. Raymond, 2015/04/15
- Re: [gpsd-dev] Modifying (severly) hardware.html, Hal Murray, 2015/04/16
- Re: [gpsd-dev] Modifying (severly) hardware.html, Gary E. Miller, 2015/04/16
- Re: [gpsd-dev] Modifying (severly) hardware.html, Eric S. Raymond, 2015/04/16
- Re: [gpsd-dev] Modifying (severly) hardware.html, Gary E. Miller, 2015/04/16
Re: [gpsd-dev] Modifying (severly) hardware.html, Gary E. Miller, 2015/04/13