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Thursday, October 3, 2019

Look out for the second 2019 GPS week number rollover

If you're a time nut, a GPS nut, or just paying attention to certain peculiar sources, you might have read that the GPS (Navstar, if you want to be particular about it) had a "Y2K" type situation happen earlier this year. There's a 10 bit number representing the week number, and for the second time since it launched, it rolled back around from 1023 to 0.

Yes, really.

Since it happened six months ago, you'd think that if you got through it, you're good to go, right? Heh, yeah, well, no, not so much.

It seems like nobody's really talking about this yet, but apparently, certain LTE chipsets have an OFFSET WEEK... and they haven't hit 1023 yet. Oh no. According to what I've managed to dig up, they're going to hit it 2019-11-02 at 23:59:42Z.

"Big deal", you might think. Well, think again. Do you have a car that has a GPS-driven nav system in it? Does it use one of these chipsets? If so, you might have about one more month of sanity and then it's probably going to lose its mind.

How do I know? I got a recall notice in the mail this afternoon.

Yes, my car needs to be patched. First smart TVs and now cars.

I've been able to find two reference points for this. There's this note and also at least one other site which seems sketchy so I won't link to it here.

What a mess.