Udo van den Heuvel wrote:
> I now have a patch for the NMEA refclock that comes with ntp to make it
> work with linuxPPS. (thanks to Folkert and Rodolfo)

Some bits:

Info about the reference NMEA ntp driver:

http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver20.html


Original LinuxPPS snapshot:

http://ftp.enneenne.com/pub/projects/linuxpps/Snapshot/


The patch for the nmea refclock that we made and the 2.6.16 kernel
patches for LinuxPPS, adapted from the linuxpps-current snapshot:

http://time.qnan.org/linux2.6-pps/

(alternative patch has slightly different pps source registration, is
that needed?)

nmea3.patch is the ntpd refclock patch.
On my FC5 box I built the stock ntp 4.2.0.a.20050816-14 with all clocks
disabled in the SPEC: %configure --sysconfdir=%{_sysconfdir}/ntp
--bindir=%{_sbindir} --disable-all-clocks --disable-parse-clocks
--with-openssl-libdir=%{_libdir} --enable-linuxcaps  --enable-NMEA
--enable-LOCAL-CLOCK

(except of course NMEA and the local clock)

This is in ntp.conf:

server 127.127.20.0 prefer minpoll 4
fudge 127.127.20.0 flag3 1 flag2 0 time1 0.0

See
http://time.qnan.org/ and/or the Garmin documentation at
garmin.com/manuals/425_TechnicalSpecification.pdf for connecting the GPS
 18 to the PC.


Please review the patches before using them.


> Things is that I read that the NMEA driver expects PPS after the NMEA
> data. Now it appears that ntpd, using the patched NMEA driver, syncs up
> very nicely with no offset, just as when using shmpps.
> That is why I would like some comments on the driver and/or feedback on
> the patch.
> Anybody?

This is still a bit vague to me. Maybe also see
https://ntp.isc.org/bugs/show_bug.cgi?id=610.
_______________________________________________
timekeepers mailing list
[email protected]
https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers

Reply via email to