[time-nuts] Adafruit Ultimate GPS timing message arrival times

David J Taylor david-taylor at blueyonder.co.uk
Mon Aug 1 12:57:27 EDT 2016


From: Mark Sims

Well,  the whole point of the exercise is to see how well you can do if you 
DON'T have an internet connection, a 1PPS signal,  or a stratum 1 time 
server available...  only the humble messages coming from a 10 dollar GPS 
receiver.  Try getting a net connection in the middle of the Gobi desert 
(where one user uses Lady Heather's time sync feature to keep their system 
clocks reasonably accurate).


If you can put the receiver into a binary message mode, you can usually do 
better than NMEA (but, surprisingly, usually not by much).  And by selecting 
a receiver that has known good / stable message timing you can do 
surprisingly well.
========================================

Well, yes, but if you choose a GPS receiver wisely it also has PPS, even on 
some of the cheapest eBay units.  Of course, what is best depends on what 
accuracy the user needs, and how much they are prepared to pay.

Cheers,
David
-- 
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor at blueyonder.co.uk
Twitter: @gm8arv 



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