[Voyage-linux] Re: PPS kernel patches

[Mark Phillips]

I have mine setup in a similar way but it is not a true time server in
that because of the lack of a disciplining kick on a regular basis it is
able to drift between time updates.

The problem with NMEA time strings is that they tend to come in a
cluster and not at all every second or 3 seconds or 5 seconds. They come
along whenever the GPS processor has time to spit them out.

The 1PPS pulse from the GPS system is not derived from the decoded data
but rather is an inherant component of the GPS signal along with the
10KHz pulse and thus is more reliable.

I'd still like to see a 1PPS patched kernel particularly as it would
then allow for connections to things like Frequency Standards and LORAN
RX's etc. Heck, one could even connect it up to the mains after a very
simple signal divider (trick used on clock radios etc) is added.

Mark 

On Thu, 2007-12-06 at 19:24 +0800, Kim-man 'Punky' TSE wrote:
> Hi guys,
> 
> Forget to mention, I have setup voyage attached to Garmin GPS18/USB and 
> get NTP time sync'd.  Of course, this device is not PPS-capable, but it 
> works without any patch to the kernel and NTP daemon.   See my blog article:
> 
>     http://www.punknix.com/?q=node/116
> 
> Regards,
> Punky
> 
> Mark Phillips wrote:
> > Now I think about it, updating the gpsd package would also be useful for
> > this purpose.
> >
> > FYI, my NTP server is running Voyage on a Neoware N3000 thin client
> > (ebay $20). It has a 300MHz via processor in it as well as an IDE
> > interface which is now running a CF card. The GPS RX plugs into ttyS0
> > and I'm running gpspipe on ttyS1 to allow my Nixie tube clock to correct
> > itself.
> >
> > Mark
> >
> > On Fri, 2007-11-30 at 05:10 +0000, Clark wrote:
> >   
> >> Mark Phillips <g7ltt at ...> writes:
> >>
> >>     
> >>> Hi all,
> >>>
> >>> Is there anywhere that I can register a feature request for adding PPS
> >>> to the kernel for use in NTP apps? This would be really handy I think.
> >>>
> >>> Thanks
> >>>
> >>> Mark
> >>>
> >>>       
> >> I would really like that too!  
> >>
> >> I have been using Voyage to try to create an NTP appliance  'cause the
> >> commercial ones are WAY beyond my budget!
> >>
> >> I appreciate the work on Voyage so far!
> >>
> >> Thanks!
> >>
> >>
> >> _______________________________________________
> >> Voyage-linux mailing list
> >> Voyage-linux at list.voyage.hk
> >> http://list.voyage.hk/mailman/listinfo/voyage-linux
> >>     
> 
> 
-- 



Mark Phillips, G7LTT/NI2O
Randolph, NJ