Active5 months ago
What is the GPS Week Number Rollover (WNRO)? Our testing shows the vast majority of Garmin GPS devices will handle the WNRO without issues. The GPS provides accurate timing information by counting the number of seconds into a week, and the week number is stored as a ten-bit binary number. This means the range of weeks is limited to 1024 weeks in total, i.e. 19.7 years, before it rolls over to 0 again. The most recent rollover took place on the 6th of April, 2019.
On April 6 2019 the second rollover event occurred in the GPS system. GPS time stamps consist of a 10 bit week number and seconds into the week. The first rollover was in August 1999.
I would expect that there is a constant in the firmware to correct for this, and it needs to be updated.
Alas: Delorme has been absorbed by Garmin and since discontinued, and Garmin has seized on this as an opportunity to sell new devices to people. There is no firmware update to correct this.
How reasonable is it to reverse engineer the firmware to find and fix this?
Firmware downloads are available here:
Note that this does not affect the ability to navigate, but all timestamps are off by 7 * 1024 days in the past.
Correction: After 2 hours sitting under an open sky, it is still reporting, 'No fix'
Sherwood Botsford
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1 Answer
That was fast.
Garmin has put a new firmware version on their website here:
Applied, and indeed it fixes the issue.
![Gps Gps](https://i-cdn.phonearena.com/images/article/115118-two_lead/Will-last-nights-GPS-date-based-rollover-get-you-lost-today.jpg)
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Active5 months ago
On April 6 2019 the second rollover event occurred in the GPS system. GPS time stamps consist of a 10 bit week number and seconds into the week. The first rollover was in August 1999.
I would expect that there is a constant in the firmware to correct for this, and it needs to be updated.
Alas: Delorme has been absorbed by Garmin and since discontinued, and Garmin has seized on this as an opportunity to sell new devices to people. There is no firmware update to correct this.
How reasonable is it to reverse engineer the firmware to find and fix this?
Firmware downloads are available here:
Note that this does not affect the ability to navigate, but all timestamps are off by 7 * 1024 days in the past.
Correction: After 2 hours sitting under an open sky, it is still reporting, 'No fix'
Sherwood Botsford
Sherwood BotsfordSherwood Botsford1,00033 gold badges1313 silver badges2525 bronze badges
1 Answer
That was fast.
Garmin has put a new firmware version on their website here:
Applied, and indeed it fixes the issue.
Sherwood BotsfordSherwood Botsford1,00033 gold badges1313 silver badges2525 bronze badges