[time-nuts] Beaglebone NTP server

Brian Lloyd brian at lloyd.aero
Thu Dec 11 14:32:15 EST 2014

On Thu, Dec 11, 2014 at 1:22 PM, Bob Bownes <bownes at gmail.com> wrote:

> If there is always a system running, why go with the bbb? I use the file
> server in the basement fed with 1pps to the non USB serial port from a
> TBolt in my office.
> You do have a file server in the basement don't you? :)

Yes, I do. Two in fact. They are two of the machines running 7x24 on the
network. Unfortunately I have found that NTP on them does not perform well.

So being able to throw a $55 board at the problem of optimizing NTP
performance and decoupling it from the up/down status of anything else on
the network makes sense to me. I consider routing, DNS, and NTP to be
services of the network infrastructure and should be independent of
anything else.

> I suppose it would be an interesting experiment to feed an NTP server with
> several PPS signals (either simultaneous or offset) to see how it handles
> it. Or to set up an NTP chorus fed from multiple PPS sources or even a
> single PPS source to see how they average out. Maybe over the holidays. I
> really should finish up running the coax for a shared GPS antenna to the
> basement.

That does make sense to me.

> Bob
> PS: As to the buy a second BBB/RPi question, I've taken to buying what I
> think will be key spare parts for projects and stocking them. Each project
> gets a shoebox sized storage bin on the shelves in the basement. One part
> of the shelves is completed projects, the other is in process. It has the
> added side benefit of telling me when I have too many unfinished projects.
> :)

That makes sense to me too. As for the 1U time and frequency server, there
is a LOT of extra space in the 1U box for an extra BBB and, potentially,
for another LTE-lite. Of course, the NTP function will work with just a
generic GPS module with 1pps out.

Said: are you going to be doing another run of LTE-lite eval boards? I
think I would like to get one as a spare.

Brian Lloyd
Lloyd Aviation
706 Flightline Drive
Spring Branch, TX 78070
brian at lloyd.aero
+1.210.802-8FLY (1.210.802-8359)

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