[time-nuts] Lady Heather coming soon to a Linux box near you...

[Chris Albertson]

The install is easy as NTP comes with most Linux distributions.  So it
would likely already be there and all you do is edit the .conf file
Again the problem with LH is that it and NTP both want access to the
GPS' serial port.

NTP can be configured to NOT require access to the GPS' serial port
but if you do that NTP will not know the time of day.  It WILL know
when the seconds click over because of the PPS.   Not a bad problem as
getting the time of day from some other source to within a few tens of
milliseconds is easy.

On Fri, Apr 22, 2016 at 6:20 AM, paul swed <paulswedb at gmail.com> wrote:
> Chris,
> Quite the good point on the TBolt overkill and power. But the whole reason
> for LH is to monitor an operating TBolt so a great use for something
> already sucking power is a NTP server.
> As I recall there was work using the Pi 1 to make a ntp server and that
> could use a simple gps receiver dedicated to the system. Its installation
> was pretty simple.
> Interesting project and simply hope the install is dumb simple and stupid.
> Regards
> Paul
> WB8TSL
>
> On Fri, Apr 22, 2016 at 2:01 AM, Chris Albertson <albertson.chris at gmail.com>
> wrote:
>
>> Neither of those two programs require much in the way of CPU power and
>> the Pi 3 is a very powerful computer.  The Pi 3 could be doing several
>> additional things all at once.  I doubt NTP and LH together would use
>> 10% of the Pi 3's CPU.
>>
>> The problem is that I think BOTH NTP and LH will want to communicate
>> with the T-bolt's serial port.  You'd have to figure out  way around
>> that.  They both can't have exclusive access.   One way might be
>> software like gpsd to make the GPS available via a socket interface to
>> multiple users another way would be to configure NTP to use the "atom"
>> reference clock.  This just uses a PPS only and not the serial port.
>> But then NTP would need another clock to "number the seconds" which
>> could be another NTP server out on the Internet.
>>
>> My opinion is that a Thunderbolt is over kill for NTP.  Not only that
>> but it uses a lot of power.  Better to use a tiny, low power GPS
>> receiver for NTP.  It runs 24x7 so it adds up.
>>
>> On Thu, Apr 21, 2016 at 3:09 PM, Mark Sims <holrum at hotmail.com> wrote:
>> >>Would there be enough horsepower for a Pi 3 to run Lady Heather and act
>> as a stratum 1 NTP server?
>> > I suspect so,  the PI3 has quad core 64-bit capable 1.2GHz processor.
>> The PI3 seems to be about 50% faster than the PI2.   It also runs about
>> code about as fast as a 2 GHz Pentium 4.   But the ethernet interface is
>> via a USB bridge (or maybe some other serial interface on the PI3).  Not
>> the best way to do things...  Also,  the current PI Linux distros are all
>> 32-bit.
>> > I have the sound file issue worked out (system() a background shell that
>> invokes aplay).  My old code left off the & on the shell command and it was
>> not returning until the sound finished... d'oh
>> > I also have the PI color issue resolved...
>> > Now to finish up the serial port init code...  Oh,  and also the
>> ethernet socket code...
>> > I'm picking up one of those 7" PI LCD screens tomorrow...  should make
>> for a nice package.  But they cost twice what the PI does...
>> >
>> >
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>>
>>
>> --
>>
>> Chris Albertson
>> Redondo Beach, California
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-- 

Chris Albertson
Redondo Beach, California