On Thu, Jun 20, 2013 at 3:39 AM, Chris Howard chris@elfpen.com wrote:

I'm using the original BeagleBone. it should work on the BeagleBone Black.

If your GPS receiver is using 3.3V logic, wiring it up is
straightforward, similar to the Raspberry Pi NTP server. I will probably
setup a page describing this.

I have a practical application for this, I'm anxious to see your web page
on how to do it.  Thanks.

eric

On Thu, Jun 20, 2013 at 12:37 PM, Gabs Ricalde gsricalde@gmail.com 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 :)

Cheers,
Henry

On Thu, Jun 20, 2013 at 7:37 PM, Gabs Ricalde gsricalde@gmail.com wrote:

Hi

The quick / dirty / easy way for any of the NTP stuff with a GPSDO is to simply run the PPS in. PPS into serial is one way, pps into a GPIO is another way.

Bob

On Mar 26, 2014, at 5:51 PM, Henry Hallam henry@pericynthion.org wrote:

On Wed, Mar 26, 2014 at 4:51 PM, Henry Hallam henry@pericynthion.orgwrote:

Actually, I was thinking of doing exactly the same thing.  I am interested
in any answers for this too.

--
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
brian@lloyd.com
+1.916.877.5067

On Wed, Mar 26, 2014 at 5:05 PM, Bob Camp lists@rtty.us wrote:

Well, yeah. I figured that I would run the 1pps from my T-bolt to a GPIO
line with appropriate clamping to 3.3V.

But if anyone has done this before and run into anything of note, that
would be nice to know ahead of time.

--
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
brian@lloyd.com
+1.916.877.5067

Hi

With a GPIO pulse width should not be an issue. With RS-232 you might have needed a pulse stretcher.

Bob

On Mar 26, 2014, at 7:18 PM, Brian Lloyd brian@lloyd.com wrote:

On Wed, Mar 26, 2014 at 2:51 PM, Henry Hallam henry@pericynthion.orgwrote:

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

On Wed, 26 Mar 2014 17:40:07 -0700
Chris Albertson albertson.chris@gmail.com wrote:

Job number one on the Beaglebone Black (and I assume the regular
version) is to install NTP. Otherwise it doesn't even know the date. It
has no battery for RTC.

Beyond that, I haven't found a very clear way to get the gpio-pps going.

On Wed, Mar 26, 2014 at 5:51 PM, Henry Hallam henry@pericynthion.orgwrote:

Here's an example for the Black.  I believe the same ideas apply to the
Beaglebone (White).

http://the8thlayerof.net/2013/12/08/adafruit-ultimate-gps-cape-creating-custom-beaglebone-black-device-tree-overlay-file/

I prefer the Beaglebone to the Pi because of the silly USB glitch but out
of three BBBs only one will run for more than a month without wedging.
This may be because I run Debian but as with the Pi USB bug it's not much
comfort when the box fails.  The Pi I use as an NTP server ran for 4 months
and developed a filesystem error.  It's been up two months post-repair.  If
I depended on a server built around a dev board I'd be careful to make the
SDcard/eMMC read-only and build more than one.

On Wed, Mar 26, 2014 at 7:17 PM, Bob Camp
<lists@rtty.usjavascript:_e(%7B%7D,'cvml','lists@rtty.us');

That is what I was thinking as well. Any suggestions on software issues in
getting this running?

--
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
brian@lloyd.com javascript:_e(%7B%7D,'cvml','brian@lloyd.com');
+1.916.877.5067

--
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
brian@lloyd.com
+1.916.877.5067

Much appreciated. I have that GPS. It didn't occur to me to build my
own cape. Had I known, I would have ordered that board had I seen this
webspage. I can probably cut some out of perf board.

On Wed, 26 Mar 2014 21:37:43 -0400
Paul tic-toc@bodosom.net wrote:

On 26/03/14 23:18, Brian Lloyd wrote:

Can I suggest you consider FreeBSD ? You can use the TIMER4-7 input pins
as PPS input for a better PPS. See the following URL for details:

http://lists.freebsd.org/pipermail/freebsd-arm/2013-February/004769.html

If I recall correctly, the patch is in the FreeBSD 10 snapshots for the
Beaglebone, so you don't need to apply it, but you will need to enable
PPS and ensure one of the four TIMER pins is set to input in the DTS
and recompile.

Iain

Thanks for all the hints everyone.  Lots to try!

Henry

On Thu, Mar 27, 2014 at 2:41 AM, Iain Young iain@g7iii.net wrote:

On Wed, Mar 26, 2014 at 5:51 PM, Henry Hallam henry@pericynthion.org
wrote:

I've managed (almost by accident) to run my dev boards and related GPS off
the same power until this one.  In the BBB instance having two power
supplies added a fatal level of noise to GPIO input.

On Thu, Mar 27, 2014 at 12:01 AM, nuts nuts@lazygranch.com wrote:

Turns out this thread points out an issue which will need to checked:
https://groups.google.com/forum/#!msg/beagleboard/emMCqt_mllI/bf7jL_ahPjYJ

I'm currently not able to simultaneously read the serial output and the
PPS.  Some minor issue I'm sure.

If compiling a kernel is required and too daunting, then there's
rpi_gpio_ntp: http://www.vanheusden.com/time/rpi_gpio_ntp/
Initially only for raspberry pi but I noticed I made it generic enough
to work on all linux systems with pps via gpio.
On my rpi the jitter is between 2 and 10us iirc but it is a while since
I tested it. A quick peak shows me currently 3us jitter. Not bad for a
userspace solution imho.

Folkert van Heusden

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Regarding the fs error: consider replacing ext3 for f2fs. F2fs does
software wear leveling.

Folkert van Heusden

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