[time-nuts] Getting ntpd to work with Garmin LVC-18x and Ubuntu 16.04..

Howard Leadmon howard at leadmon.net
Sat Jul 16 16:32:20 EDT 2016


 I made sure that even by hand I had run the ldattach, and that /dev/pps0 existed and was also linked to /dev/gpspps0 which is the case.

 I have also run ppstest, and show a pps stream, granted the weird thing is it seems like I get two lines of the same output ever second so not sure what is up there.

# ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1468700910.979003708, sequence: 44155 - clear  1468700910.078946163, sequence: 516263
source 0 - assert 1468700910.979003708, sequence: 44155 - clear  1468700911.078993120, sequence: 516264
source 0 - assert 1468700911.979006178, sequence: 44156 - clear  1468700911.078993120, sequence: 516264
source 0 - assert 1468700911.979006178, sequence: 44156 - clear  1468700912.079007527, sequence: 516265
source 0 - assert 1468700912.978993897, sequence: 44157 - clear  1468700912.079007527, sequence: 516265
source 0 - assert 1468700912.978993897, sequence: 44157 - clear  1468700913.079009555, sequence: 516266

 If I pull the serial line, as expected it loses the source and stops counting.  

 I also loaded up gpsd thinking it might help, but it didn't seem to resolve the issue.   

 I figure something isn't right, but I am just not quite sure how to debug this, and all my google-fu hasn't come up with anything that has resolved the issues.   So much for easy..   LOL



---
Howard Leadmon 


> -----Original Message-----
> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Hal
> Murray
> Sent: Saturday, July 16, 2016 3:15 PM
> To: Discussion of precise time and frequency measurement <time-
> nuts at febo.com>
> Cc: hmurray at megapathdsl.net
> Subject: Re: [time-nuts] Getting ntpd to work with Garmin LVC-18x and
> Ubuntu 16.04..
> 
> 
> howard at leadmon.net said:
> > Does anyone have any ideas, or have this all working under Ubuntu 16.04
> LTS?
> > I would sure love to get my time server back online, as I pretty much
> > have everything on the network sync with it..
> 
> The PPS stuff on Linux needs some magic setup.  You need to run something
> like:
> 
> if [ ! -e /dev/gps0 ]; then
>   ln -s /dev/ttyS0 /dev/gps0
>   setserial /dev/ttyS0 low_latency
>   ldattach 18 /dev/gps0 & # gets /dev/pps0
>   sleep 10
> fi
> 
> I put that in /etc/sysconfig/ntpd which gets run by the startup scripts before
> starting ntpd.
> 
> When you get to systemd, it doesn't actually run /etc/sysconfig/ntpd, just
> scans it for OPTIONS=xxx I haven't found a great solution.  What I've been
> doing is use systemctl to disable autostart and start ntpd from rc.local by:
>   /bin/sh /etc/sysconfig/ntpd
>   /usr/sbin/service ntpd start
> 
> 
> 
> --
> These are my opinions.  I hate spam.
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-
> nuts
> and follow the instructions there.



More information about the time-nuts mailing list