[time-nuts] Beaglebone NTP server

Chris Albertson albertson.chris at gmail.com
Wed Mar 26 20:40:07 EDT 2014


On Wed, Mar 26, 2014 at 2:51 PM, Henry Hallam <henry at pericynthion.org>wrote:

> Hi Gabs,
>
> I have a Z3805A and a Beaglebone, and would like to set up an NTP
> server for the lab.  Any kernel drivers and/or setup hints would be
> appreciated :)
>
> It's best to go in steps.  Resist the temptation to simply connect
everything, turn it on and see it is works.

The first step is to get NTP installed and running using Internet pool
servers for reference clocks.   Make sure this is working reliably.  NTP
may already be mostly configured.  I don't know.

Next make sure the kernel level PPS diver is working.  To test PPS there is
a user-land test program you can run that simply prints the time of each
pulse to the console.  Besure to watch both the voltage levels (the Beagle
is 3.3 volts) and the polarity of the pulse.  If you get the polarity wrong
it will appear t work but the timing will lag by the pulse width (because
the falling edge is now the raising edge.)
Be sure and match up the levels for both serial and PPS.

After both of the above, adding a GPS based reference clock to NTP is easy.
 All you do is edit the config file.   Obviously I've left out much detail
but the biggest thing is to follow the step by step process
-- 

Chris Albertson
Redondo Beach, California


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