[time-nuts] Raspberry PI 3 NTP server with GPS time data.

Artek Manuals Manuals at ArtekManuals.com
Sun Apr 24 22:22:06 UTC 2016


Jan

IS the GPS antenna "outside" with a clear view of the sky say at least 
down to 20 degrees elevation or is it "inside" the building?

Dave


On 4/24/2016 2:51 PM, jan hugo prins wrote:
> Hi,
>
> To get a more stable NTP source into our production network I have
> started exprerimenting with a Raspberry PI 3 with a GPS head. GPS data
> is coming in fine, but the time is jumping around like a wild horse. The
> result is that the only thing I get out of this experiment so far is a
> more stable PPS signal in my NTP config but after some time both the GPS
> time and the PPS are marked a false ticker and the only thing left is
> the external reference clocks from outside our own network.
>
> Parts used:
> Raspberry PI 3
> Adafruit GPS head: ADA-2324
> External GPS antenna with 5 meter cable.
>
> My NTP config looks like this:
>
> logfile /var/log/ntpd.log
> logconfig = all
> driftfile /var/lib/ntp/ntp.drift
> statsdir/var/log/ntpstats/
> statistics loopstats peerstats clockstats
> filegen loopstats file loopstats type day enable
> filegen peerstats file peerstats type day enable
> filegen clockstats file clockstats type day enable
> server 127.127.22.0 minpoll 4 maxpoll 4 prefer
> fudge 127.127.22.0 refid PPS flag3 1
> server 127.127.28.0 minpoll 4 maxpoll 4 iburst
> fudge 127.127.28.0 refid GPS time1 +0.550 flag1 1 stratum 4
> server ntp0.nl.uu.net
> server chime6.surfnet.nl
> server chime5.surfnet.nl
> server ntp1.virtu.nl
>
> Now I got the idea that I might be able to use a DCF77 receiver to get a
> stable timesource, but on the other hand, if the cause of my problem is
> internal to the Raspberry PI setup then I might have exactly the same
> problem with the DCF77 receiver.
>
> The average on the NTP clocksource is close to 0.
> root at raspberrypi:/var/log/ntpstats# cat peerstats |grep 127.127.28.0
> |awk '{print $5}'| tail -n 1500 | awk 'NR == 1 { max=$1; min=$1; sum=0 }
> { if ($1>max) max=$1; if ($1<min) min=$1; sum+=$1;} END {printf "Min:
> %d\tMax: %d\tAverage: %f\n", min, max, sum/NR}'
> Min: 0    Max: 0    Average: 0.001101
>
> Could anyone give me some advice on how to get this working? Or is my
> idea to use a GPS clock to create a stable NTP setup the wrong way to go?
>
> Thanks for any advice.
> Jan Hugo Prins


-- 
Dave
Manuals at ArtekManuals.com
www.ArtekManuals.com

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus




More information about the Time-nuts_lists.febo.com mailing list