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Re: [questions] GPS+PPS vs NTP server, why a huge offset ?




> On 17 Jun 2022, at 17:12, Martin Burnicki <martin.burnicki@xxxxxxxxxxx> wrote:
> 
> Daniel O'Connor wrote:
>>> On 17 Jun 2022, at 12:52, Jim Pennino <jimp@xxxxxxxxxxxxxxxxx> wrote:
>>> If all you need is accuracy in the 2 millisecond range, most recent USB
>>> GNSS dongles will achieve that without PPS.
>> You can easily do better than that with GPS/PPS over USB.
> 
> Hm, USB v1 has only 1 ms timing frames, so if some USB v1 device (e.g. an USB hub) is involved, the accuracy may indeed be only in the range of ms.

Finding a USB 1 hub in this day and age would be an achievement in and of itself.

I do not think it is useful to claim it "might" be so poor when you would have to try very hard to make it that bad.

The basic case of "buy USB GPS interface, connect to PC" would be vastly better.

--
Daniel O'Connor
"The nice thing about standards is that there
are so many of them to choose from."
-- Andrew Tanenbaum
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