[lug] Time sync w/GPS or radio

Jason Vallery jason at vallery.net
Thu May 15 15:41:31 MDT 2008

Hi All,

I'm a bit late to this thread, but I was working on a separate project
using GPS and came across an interesting product.  Garmin makes a
"puck" GPS receiver that just has a serial cable output on it.  It is
a fairly dumb device that when powered up generates a NMEA 0183 data
stream on the serial interface.  For $70 you can't beat the price.

You can see it here:

If you look at the NMEA spec the data stream contains the UTC time.
It seems like it would be pretty trivial to write up a shell script
that monitors the serial interface and sets the clock based on the
incoming data stream.


I just ordered one and I can't wait to play with it.


On Thu, May 8, 2008 at 4:32 PM, George Sexton <gsexton at mhsoftware.com> wrote:
> I've been wanting a time receiver for a long time. In a previous life, I was
> a calibration technician so I've been fascinated with time and frequency
> standards for a long time. What's been killing me has been the price. It's
> tough for me to explain to my wife that I want to buy a $1500 GPS time
> receiver because I think it would be cool. It's neat to see the Beaglesoft
> one is much cheaper.
> I looked at the Radio Sync thing from the Beaglesoft folks, and it's nice at
> $220, but it's not directly supported by NTP. Someone would have to write a
> driver for it.
> I saw their GPS receiver is a Garmin GPS-16. For kicks, I went to Garmin's
> site and found the unit for $105.
> https://buy.garmin.com/shop/shop.do?cID=158&pID=13194
> It looks like you would need to follow these instructions to create an
> RS-232 interface and power supply. There are also instructions on getting
> the PPS stuff working, which is essential for higher accuracy:
> http://time.qnan.org/
> I'm sure that even if you purchased the kit from Beaglesoft, you would have
> to do the kernel PPS steps on the URL.
> This would be a really cool project. I'm halfway handy with a soldering iron
> and I'm sure it wouldn't take much more than an hour to create the PCB.
> Lori Reed wrote:
>> IME, gps devices, at least hand held and pcmcia devices, have, at best,
>> problematical indoor reception. A bit of quick googling found this:
>> http://www.atomictimeclock.com/radsynhome.htm
>> I'm sure there are others.
>> Just curious, what is the url for the UK vendor you reference?
>> Lori
>> Gary Hodges wrote:
>>> I have some remote machines w/o internet access.  I get around that by
>>> dialing in a couple times a day, but I've never liked that solution. But
>>> what prompted me to start looking for a solution is...  You all will love
>>> this...  I have a machine on the net behind the firewall of a very large
>>> government organization where I'm not able to use a time server outside the
>>> network.  And, get this, they don't keep the time set on their internal time
>>> server.
>>> In case anyone is interested, I got a price quote from that UK vendor
>>> this morning.  $1590 for a GPS solution and $995 for a WWVB solution.
>> _______________________________________________
>> Web Page:  http://lug.boulder.co.us
>> Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
>> Join us on IRC: lug.boulder.co.us port=6667 channel=#colug
> --
> George Sexton
> MH Software, Inc.
> Voice: +1 303 438 9585
> URL:   http://www.mhsoftware.com/
> _______________________________________________
> Web Page:  http://lug.boulder.co.us
> Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
> Join us on IRC: lug.boulder.co.us port=6667 channel=#colug

Jason Vallery
jason at vallery.net

mobile: +1.720.352.8822
home: +1.303.993.3712
web: http://vallery.net/

More information about the LUG mailing list