Mark and Clark,
Don't get me wrong, but I spend a few minutes on the links below and I
found that it is indeed for 2.0/2.2/2.4 kernel!?
Luckily I find this one.
http://wiki.enneenne.com/index.php/LinuxPPS_support
and patches here:
http://ftp.enneenne.com/pub/misc/linuxpps/patches/
Including patch is OK, but patching ntpd may be a issue ... (for me).
Instead, you need special equipment for getting PPS signal, at least you
need soldering things. What GPS device you usually uses for 1PPS?
Regards,
Punky
Mark Phillips wrote:
You need to look at the NTP sources. These contain a kernel patch. If I
understand it correctly, GPSD and others pick up the 1PPS via the kernel
(usually connected to the DCD pin on the serial port).
They are available here ftp://ftp.kernel.org/pub/linux/daemons/ntp/PPS/
and a rough howto is available here http://etienne.favey.ch/ntp/
Thanks very much for looking at this!
Mark
On Mon, 2007-12-24 at 09:27 +0800, Kim-man 'Punky' TSE wrote:
Hi ,
But where can I get the 1PPS patch for Linux and instruction? As far as
I read gpsd documentation, it indeed support 1PPS as long as you have
the proper equipment.
What is the different between gpsd support for 1PPS and the 1PPS patch
for the time server?
Regards,
Punky
Mark Phillips wrote:
Any thoughts/comments on this Punky?
On Mon, 2007-12-10 at 14:33 -0500, Mark Phillips wrote:
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 <[EMAIL PROTECTED]> 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!
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Regards,
Punky
Voyage Solutions (http://solution.voyage.hk)
* Embedded Solutions and Systems
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