[time-nuts] Lowest Power NTP Server

[Adrian Godwin]

Does it need to be actual NTP, or could it use a custom broadcast protocol
for the 'last yards' ?

I'm imagining something that broadcasts a packet subject to the usual
anticollision strategies, then in the next packet it reports how far off it
actually was (like a GPS sawtooth frame).

Some other random thoughts  :

There are some very small and possibly low-power linux boards around. e.g
https://onion.io/store/omega2/

I pinged my laptop over the local (rather outdated but not busy) wifi. Most
of the time I got pings in the range 1-3ms. Occasionally there was a 20, 30
or even 90ms response. There is only a single wireless hop and almost no
contention (maybe a mobile phone idling) : it's wired from desktop to
wireless router. I don't know what causes that but it may be the ESP32 is
not doing much worse than anything else.




On Mon, Dec 2, 2019 at 8:02 PM Bob kb8tq <kb8tq at n1k.org> wrote:

> Hi
>
> Wired is out for this particular setup. It needs to be some sort of
> wireless. It all would
> be *much* more simple with wires.
>
> Bob
>
> > On Dec 2, 2019, at 12:46 PM, Robert LaJeunesse <lajeunesse at mail.com>
> wrote:
> >
> > If wired Ethernet seems to be the way to go consider the Orange Pi Zero
> - about the cheapest wired Ethernet board available that runs Linux.
> Ethernet is via on-chip MAC and phy, so no USB path delays.
> http://www.orangepi.org/orangepizero/
> >
> > Plenty of support exists on the web, for example:
> https://lucsmall.com/2017/01/19/beginners-guide-to-the-orange-pi-zero/
> >
> > Bob L.
> >
> >> Sent: Monday, December 02, 2019 at 9:56 AM
> >> From: "Tim Shoppa" <tshoppa at gmail.com>
> >> To: "Discussion of precise time and frequency measurement" <
> time-nuts at lists.febo.com>
> >> Subject: Re: [time-nuts] Lowest Power NTP Server
> >>
> >> Bob, I find that 2.4GHz Wi-Fi UDP latency with ESP8266 will frequently
> be
> >> tens of milliseconds and is never/rarely consistent.
> >>
> >> There are specialized non-WiFi 2.4GHz systems for time distribution that
> >> are far more consistent (possibly even at the tens of microseconds). I
> >> think several years ago on this list, we were talking about tricking
> >> commodity WiFi chipsets into doing these but haven't seen anything as of
> >> late.
> >>
> >> Tim N3QE
> >>
> >> On Mon, Dec 2, 2019 at 8:02 AM Bob kb8tq <kb8tq at n1k.org> wrote:
> >>
> >>> Hi
> >>>
> >>> Indeed, if you get up into the “many tens” of  ms, that rules it out
> in my
> >>> application.
> >>> A consistent 90 ms would be ok, you could compensate for that. Random
> >>> flopping
> >>> from 4 to 90 … not so much.
> >>>
> >>> It seems like that sort of jitter would get in the way of a lot of
> things.
> >>> I guess that just
> >>> shows how little I know about a lot of things :)
> >>>
> >>> Bob
> >>>
> >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at lists.febo.com
> > To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>