[time-nuts] BC637PCI 1024 week rollover

GandalfG8 at aol.com GandalfG8 at aol.com
Sun Feb 9 06:56:50 EST 2014

Oh well, full credit to Mr Trimble for getting it right, he does bake  
exceedingly nice GPS modules and the Ace3 doesn't have a rollover issue  and it 
does report the date correctly.
Unfortunately, as far as I can tell anyway, the BC637PCI takes the raw GPS  
time data from the Ace3 and performs its own calculation which is where the 
 problem seems to occur, certainly it's a 1024 week issue with the date 
from  the BC637 being displayed as June 26 1994 in all versions of the 
associated  demo software.
It is possible to set the date correctly but the next packet from the GPS  
module promptly overwrites it again.
I still don't recall seeing this before, although with two boards  behaving 
in the same fashion I'm having doubts about that, but more to the point  
these boards indicate a firmware date of 2003 which implies they were  put 
into the field like this, and that doesn't make much sense  either.
Any ideas anyone?, and again has anyone else seen this and/or am I missing  
something glaringly obvious?

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