Rollover in old electronics

[mtbc]

I am happy to keep old consumer products instead of upgrading if they continue to serve their purpose well. For example, I remain satisfied with my third-generation Amazon Kindle though maybe the later Paperwhite ones are lovely. Among my possessions is a Garmin Geko 101 GPS unit that I bought when first looking to buy land in Ohio: it helped me to tell that I was actually at the rural field that was for sale. I would look forward to it again having a similar use except that I guess smartphones now supplant it.

The Geko 101 is low-end: there is no WAAS and it does not even offer a connectivity port by which one may interface with it for data downloads or to effect upgrades but it was cheap and small, also waterproof. Mine still works fine except for revealing an amusing implementation detail: while it gets the time of day correct, it also reports a date exactly 2¹⁰ weeks anteceding the present which corresponds to the ten-bit week number encoded in the signal from the satellites.

I read that the epoch for these GPS week numbers started on January 6th, 1980. Tomorrow is 2¹¹ weeks after that. I suspect that the date displayed by my Geko 101 is about to become even more wrong.

Comments

[fanf]

I gather it is relatively common for GPS receivers to treat the week number as relative to some epoch closer to the manufacturing date (so early week numbers get an extra 1024 added). Did yours first go wrong in August 1999 or some time after?

[mtbc]

Unfortunately I have little idea when it went wrong: I use it infrequently and the display with the date on it much less still. (It has a tiny screen so I typically select only either something navigational or the fun one where the TIE fighters attack the guy on the planet.) You raise an interesting point: I just tried it again and it is yet to go doubly wrong so I guess that its second rollover remains in the future.

[goldibehr]

Are you sure the Garmin firmware can't be updated? A quick google search implies that installing the latest driver on your Windows PC will somehow update the Garmin device (over USB? or wifi?)

This link also showed up for a $40/year product to handle updates (I have no idea if this company is trustworthy or not):

https://www.solvusoft.com/en/update/drivers/gps/garmin/geko/101/model-numbers/

[goldibehr]

OK, your device has no interfaces, which makes user-driven firmware upgrade impossible. That makes Solvusoft a dishonest scammer.

[mtbc]

Thank you for looking anyway!

[wpadmirer]

I have a Kindle Fire. It was a Christmas gift from a friend, and she was upset that it gets ads. I was thrilled! It's a FIRE! I love it.