GPS oddity

[charliecoutas]

Seventeen years ago I put my home-made heating/solar (hot water) controller into operation (PIC of course). It has undergone several changes and updates over the years and a GPS module, which was there from the start, provided the time of day, month etc. A later addition provided that same time in our bedroom via an HC-12 radio link.

Yesterday the time was one hour early and a date of Sunday 7 March 2005!  I spent ages ploughing through my code trying to discover my error. The time was correct for the time of year (British Summer Time). Eventually I got down to the GPS message that gives the date and it showed 070305.

Googling around revealed that there was a "rollover" error and that old versions of GPS receivers "might need updating". I couldn't identify the unit I had but a different one in my junk box now works as expected. The bad until went into the bin.

So if you get GPS problems, this might just be the reason.

Charlie

[david]

Sounds like the 10 bit week register roll over.

https://www.gpsalliance.org/post/gps-week-number-rollover-explained

Cheers,
David