I think GPS is a significant cost in the power budget. Many users would prefer longer battery life. The option to enable GPS would be nice, but it cuts into cost and size budgets.

Amazfit Bip (S) has a GPS and still lasts for about 2 weeks in the same form factor.

How often do you use the GPS in those two weeks? It obviously only needs power if used, and tests I've read suggest it wouldn't last 2 days with lots of active GPS usage (which is to be expected, and not really a fault of the device!).

Some GPS receivers claim to get a reading in 2ms, then power down. Even doing that once a second would only have it powered 0.2% of the time.

Still quite impressive though. It defies belief getting 2 weeks out of a GPS watch charge.

From my understanding of GNSS (I did some research on it in school, about a month full-time), that only works if you have a clock synchronized to a few nanoseconds and of course up to date satellite information. This is very plausible if you do it once a second, because in 1 second your quartz doesn't drift that much or you can count cpu clock cycles perhaps, and the ephemerides don't change that often.

But once you move indoors and lose signal regularly and have a much higher noise to signal ratio, I very much doubt this can still work. I don't know about you, but I don't work in the garden, so most of the day that GNSS unit would still be listening and calculating (as I understand, the code division multiplexing means you kind of brute force the various codes until one produces a signal instead of noise) and might not even get a fix at all (my phone takes a few minutes next to a window when there is concrete on all sides except for that narrow view of the sky, and this 2018 phone is already orders of magnitude better than my previous Galaxy Note 2 was). I'm not saying it's impossible, but I would highly doubt that it consistently gets a fix in 2ms, or even 200ms, in the place where you spend most of your time.

Of course, it's mostly useless indoors anyway, but so you'd have to manually toggle it every time you go in- or outside, or somehow configure a home location where it turns off (would work great during COVID) if it has such a feature, though I wouldn't know how it would figure out when you've left home in that case. (WiFi comes to mind as an obvious solution, but then how do you explain to the user that it won't track your GPS while that WiFi is in range? It just seems like they'd drop the auto-off feature at this point.)

I would assume a common use for GPS in a watch is workout tracking, so it gets manually started and stopped when they go for a run. it'd need more time at the start to get a clean fix, but in good conditions could probably get by with short blips.

Ah, I guess it shows that I'm no fitness tracker user! I didn't realize you would already interact with the device to indicate you're starting an activity. Yep, in that case this is very plausible, and on startup it probably takes only a few seconds of continuous searching if you have as good a receiver as the 2ms claim indicates.

It is possible to do the GPS processing after the fact. You turn on the rx and listen for a few hundred milliseconds, then turn off. This is very low power. Later you push these to a server (a smartphone or the cloud) which computes the position. This is called snapshot processing.

So if you don't need the position in real time for navigation it is quite possible to track location over a week with a tiny battery. This could be time triggered and/or based on MEMs counters (which are also power friendly). Or you could calculate locally if the user explicitly asks.

https://ieeexplore.ieee.org/document/5708033 http://publica.fraunhofer.de/documents/N-464241.html

Twice a day for about an hour

Thanks for the clarification, that's surprisingly good, and indeed seems useful for many.

Check out the Amazfit Bip (S) watch.

Cheap, sleek, waterproof, gorilla glass always-on display, battery lasts a month, does GPS tracking without smartphone connection and you can sync it via Gadgetbridge to keep all your data private without any account/cloud services.

Available on B&H : https://www.bhphotovideo.com/c/product/1566703-REG/amazfit_w...

Unfortunately they no longer make them. Or at least I could not find any to be bought.

Timex makes a $120 GPS Ironman R300. It's apparently a Huami/Amazfit backend.

I've been very pleased with it. Great battery life, even with GPS while running. I found it comparable to Garmins in that respect.

The chunky looks could turn people off, but I prefer ugly retro-looking stuff :)

Edit: here is DC rainmaker's review https://www.dcrainmaker.com/2020/06/timex-r300-gps-smartwatc...

I'm pretty sure they do; even established stores have started carrying them around here. Check out the website as well; there's a bunch of variations of that watch now.

I have the original Bip and am very satisfied with the hardware (lasts forever, looks pretty good) and somewhat satisfied with the software (good selection of watch faces, it's gadgetbridge compatible, but activity mode is a tad bit too easy to enter and too hard to exit)

Checked the US store. There's none available. None available in Amazon Germany either.

I have the Bip S, and was trying to get that for a friend, but as I mentioned... I cannot find them in stock anywhere.

you can modify the behavior of the crown button to disable this, if i recall correctly. i think i just deactivated it - after one too many accidental presses.

You can definitely find it on the usual China gadgets marketplaces: aliexpress, banggood, gearbest, ...

You can still get them (in the UK at least) although stock seems low, you can also get the amazfit U. although it's a bit more expensive.

The Bip S is the perfect device for me. This is specifically what I was trying to find.

I bought mine on AliExpress a couple of months ago.

Yes. I found mine in August. Try to get them now.

Took me 2 minutes https://www.aliexpress.com/item/4001190040175.html

You cna get them easily with Aliexpress still.

Ebay has tons. They run $25 to $40.

As cyclist, the best option would be to have an hackable cycling pc with speedometer, hearth rate monitor, cadence and power meter. You can create then a bunch of applications for better training.

Agree. GPS is primarily the reason why i got a smartwatch. It’s so much better now that i don’t have to carry my phone with me when i cycle or run.

Bluetooth with onboard music (on some newer fitness watches) really sealed the deal for me. After going through a Pebble some years ago, I realized that I didn't actually care about the "smart" features as long as my next watch had excellent GPS performance, Spotify or some other music platform, and an always-on display to tell the time.

Any recommendations? I would love a watch that was dumb as a brick but played music and had gps. Bonus points if it is extremely simple.

I've been loving my COROS. It's quite simple, and the battery life is astonishing. No music functionality though, if that's a dealbreaker for you. I got the APEX 42mm about 5 months ago.

https://coros.com/compareChartPage.php

I'm in the market for a similar smart watch/fitness tracker and have settled on the Garmin Vivoactive 4. It hits the sweet spot between a sports watch and a fitness tracker for me, plus the battery should last about a week between charges.

Check out Garmin, tom-tom

a variety of garmin watches have gps, built-in maps and music

Check BangleJS then

That looks really interesting - thank you!