[ntp:questions] best gps receiver for time synchronization

Unruh unruh-spam at physics.ubc.ca
Tue Mar 10 17:32:06 UTC 2009


"David J Taylor" <david-taylor at blueyonder.neither-this-bit.nor-this.co.uk> writes:

>jack wrote:
>> Hi everyone,
>>
>> First of all, I thank you for all your response.
>>
>> I understand the best solution would be using an IRIG board and that's
>> what we had been using. We are now trying to make our product more
>> compact by using a small single board PC with no RS 232 or PCI slot
>> (no slot at all). Currently I am using GPS antenna with a USB
>> connection.
>>
>> I also understand that if I can get a small PC with one genuine RS232,
>> I can use Dave Hart's solution as tested by David. I will try to my
>> best to steer the project towards this direction.
>>
>> Right now, I am trying to find the best GPS antenna that outputs at a
>> consistent pace (better if the output can be configured so I only
>> receive time stamps). Any recommendations wrt that?
>>
>> Thanks again.
>>
>> Jack

>Jack,

>GPS18 LVC
>  https://buy.garmin.com/shop/shop.do?pID=223

>GPS18x LVC
>  https://buy.garmin.com/shop/shop.do?cID=158&pID=27594

>The newer "x" version appears to be a lot more sensitive, at the expense 
>of somewhat higher current consumption.  You can tell the LVC version what 
>sentences to send.  Better check the technical spec to see what the USB 
>one can be told to do:
>  http://www.garmin.com/manuals/GPS18x_TechnicalSpecifications.pdf

Unfortnately, the LVC is a serial port output, plus a PPS output. The USB
version has no PPS output and is liable to have pretty bad timing (where
good=usec).


>As others have said, the single-board PC with FreeBSD would probably be 
>the best solution.  I would go for that, except I happen to have a Windows 
>PC which will do well enough for my purposes (say: within a millisecond).

>I've even heard that you could perhaps use a router as a compact Linux PC, 
>and use the serial port which is either available on the box, or as a 
>header on the PCB.

>Cheers,
>David 




More information about the questions mailing list