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From: Nathan Owens <nathan@nathan.io>
To: "Gary E. Miller" <gem@rellim.com>
Cc: starlink@lists.bufferbloat.net
Subject: Re: [Starlink] GPS Dongle?
Date: Mon, 14 Jun 2021 12:13:55 -0700	[thread overview]
Message-ID: <CALjsLJvzEd9Hif3jHdPZdpZaAXoHufJF_AC0MdTVF10TH=sPNw@mail.gmail.com> (raw)
In-Reply-To: <CALjsLJsCgw93g1B2DZqs_npB6PVPDgXD1WyKaECrBUKvwYucag@mail.gmail.com>

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I am able to buy the same chip, the uBlox M8Q as hat:
https://www.amazon.com/MAX-M8Q-Raspberry-Multi-Constellation-Receiver-Support/dp/B08HJFYPGX/

On Mon, Jun 14, 2021 at 12:09 PM Nathan Owens <nathan@nathan.io> wrote:

> Thanks for the info Gary!
>
> Why wouldn't you recommend the hat? Anything you'd recommend that is
> actually purchasable? I can't seem to find any of the Navisys units, and
> ideally non-USB would be better?
>
> On Mon, Jun 14, 2021 at 12:07 PM Gary E. Miller <gem@rellim.com> wrote:
>
>> Yo Nathan!
>>
>> On Mon, 14 Jun 2021 10:40:36 -0700
>> Nathan Owens <nathan@nathan.io> wrote:
>>
>> > Sorry, it was MACx-1, but either way, I decided to go for an Adafruit
>> > Raspberry Pi GPS "Hat", which does 1PPS.
>>
>> I do not recommend that HAT.  There are much better ones available at
>> similar prices.
>>
>> > I'll setup a raspberry pi
>> > with RT_PREEMPT
>>
>> RT_PREEMPT is overkill.  The best you can get on a RasPi is about 54ns
>> accuracy.  Due to the clock granularity of 54ns.
>>
>> > and run as a Stratum-1 Clock locally.
>>
>> But always have other chimers in your configuration file.
>>
>> > This should
>> > help with better irtt timings. This can be done for <$100 if anyone
>> > else wants super accurate time.
>>
>> For some definition of "super".
>>
>> > > Does anyone know if any MAC1-X GPS dongles or anything similar are
>> > > available anywhere?
>>
>> They pop up now and then.  Right now GPS parts are hard to find, much
>> less at good prices.  Search for Navisys GR-601W, GR-701W, or GR-801W.
>> The "W" suffix says it outputs PPS.
>>
>> The MAC1-X, or any PPS over USB, will only get you to > 1 milli second
>> because of the USB.
>>
>> RGDS
>> GARY
>>
>> ---------------------------------------------------------------------------
>> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
>>         gem@rellim.com  Tel:+1 541 382 8588
>>
>>             Veritas liberabit vos. -- Quid est veritas?
>>     "If you can't measure it, you can't improve it." - Lord Kelvin
>> _______________________________________________
>> Starlink mailing list
>> Starlink@lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/starlink
>>
>

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  reply	other threads:[~2021-06-14 19:14 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-14 14:55 Nathan Owens
2021-06-14 17:40 ` Nathan Owens
2021-06-14 19:07   ` Gary E. Miller
2021-06-14 19:09     ` Nathan Owens
2021-06-14 19:13       ` Nathan Owens [this message]
2021-06-14 20:18         ` Gary E. Miller
2021-06-14 20:25           ` Ricky Mok
2021-06-14 20:38             ` Gary E. Miller
2021-06-17  3:00               ` Nathan Owens
2021-06-17  3:04                 ` Nathan Owens
2021-06-17  3:09                 ` Gary E. Miller
2021-06-17  3:11                   ` Nathan Owens
2021-06-17  3:15                     ` Gary E. Miller
2021-06-14 19:40       ` Gary E. Miller

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