One possibility is that the CPU is getting turned off when idle to save
power. If that includes the stuff normally used for timekeeping, things
could get screwed up when it gets turned back on. It has to reset the
time, probably getting it from the RTC.
I don't think this is the case.
Oh for convenience. I need to patch ntpd to use linux pps (afaik) and on
other systems I successfully run gpsd with ntpd (read: low jitter).
Using gpsd with ntpd reduces the jitter versus just using ntpd by itself?
No I meant that running that combination is successfully because I see
low
Hi,
I decided to buy a Nanos G20. Not too expensive, real serial port,
debian linux pre-installed.
I don't want to sound harsh as the people from Nanos probably did their
best to produce a good product, but for timekeeping it is totally crap
and also useless.
Well, unless I did something wrong.
I
folk...@vanheusden.com said:
remote refid st t when poll reach delay offset jitter
==
x127.127.28.0.NMEA. 0 l3 16 3770.000 -994.05 7.857
x127.127.28.1.PPS.
Hi,
I decided to buy a Nanos G20. Not too expensive, real serial port,
debian linux pre-installed.
I don't want to sound harsh as the people from Nanos probably did their
best to produce a good product, but for timekeeping it is totally crap
and also useless.
Well, unless I did something wrong.
folk...@vanheusden.com said:
remote refid st t when poll reach delay offset jitter
==
x127.127.28.0.NMEA. 0 l3 16 3770.000 -994.05 7.857
x127.127.28.1.PPS.
Thanks for your graphs, but what are the Y-axis units!
http://keetweej.vanheusden.com/~folkert/nanosg20.png is in ms and not
the delay, the offset instead.
Inn your billboard above, the PPS looks to be on the wrong edge -
perhaps the pulse is 250 ms wide and you are syncing to the trailing
The computer itself and the NTP installation are OK because we can see it
syncing to other NTP servers. Likely you have a problem in the way the GPS
using is connected.
Some common errors is an inverted PPS, just flip it ad see if you gets
better, it is really hard to see a 1Hz signal on a scope.
On Wed, Jul 3, 2013 at 4:14 PM, folkert folk...@vanheusden.com wrote:
Oh for convenience. I need to patch ntpd to use linux pps (afaik) and on
other systems I successfully run gpsd with ntpd (read: low jitter).
Using gpsd with ntpd reduces the jitter versus just using ntpd by itself?
It is a garmin 18x lvc.
That's pretty vanilla. It really should work. I won't be surprised if the
NMEA is off by hundreds of ms and/or has 100 ms of wander, but the PPS should
work.
Would you please try ntpd's NMEA driver, preferably from the latest ntp-dev
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] looking for low-power system for gps ntp timekeeping
NANOSG20
It is a garmin 18x lvc.
That's pretty vanilla. It really should work. I won't be surprised if the
NMEA is off by hundreds of ms and/or has 100 ms
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