🆕 blog! “Why don't smart watches use USB-C to recharge?”

It looks like the new Google's Pixel 4 watch comes with yet another incompatible change in charging technology. This is a ridiculous situation.

The original Pixel Watch used one type of wireless charging. Then the Pixel Watch 2 & 3 removed wireless charging and swapped to a different charging mechanism. And…

👀 Read more: https://shkspr.mobi/blog/2025/08/why-dont-smart-watches-use-usb-c-to-recharge/
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#gadget #usb-c #watch

Got a USB-C powered smartwatch for £16 and it is… good actually?

Heart-rate and SpO2 are broadly accurate. Can make & receive phone calls via Bluetooth. Step counter is adequate. Even has a couple of games - and a wooden fish (which I don't understand).

Full review coming later. Happy to answer any questions about it.

Has a large gallery of watch faces - decided this spoke to my mood best.

@neil I am referencing your blog post extensively!
Wonder if I can actually get any data out of it.

@neil the algorithm favours me!

@neil @Edent bit harder to lose on Toronto Island after less than a week, too

@neil @Edent Neil is why I'm wearing a colmi right now

The sleep tracking on this £16 smart watch works. The UI isn't the easiest thing to understand - either on device or in-app - but broadly matches how I felt.

Obviously the UI is poor compared to a watch costing 20x as much - but I think this is pretty impressive.

Here's a rough and ready video review.

https://tube.tchncs.de/w/vYTnG6eKghnicdNj5nkhVx

Full blog post later this week.

Not sure how many days battery life you get on an Apple watch, but this el-cheapo unit is still at 75% after a day-and-a-half of use.

That's not bad!

Obviously, it isn't doing half the stuff of a more expensive device. But it is counting my steps, tracking my heart-rate, taking calls, and showing the time.

I'm curious - what's your favourite smartwatch function?

Today's task - try to connect this to #GadgetBridge.

It is a Colmi rebranded MoYoung so I think it should work, but I need to figure out how.

If you've added a new device to @gadgetbridge before, give me a shout 😃

@neil @Edent heh, whereas I have notifications fully disabled on everything and refuse/don't want my watch to be smart. (Even though it can do that)

@neil @Edent Same for me, though my smartwatch is a Garmin running watch with maps and navigation which i do use regularly. If I were to get a second non-running watch, it's be fir notifications.
(fwiw I get 3 weeks battery if I turn off SpO2, or 2 weeks with that set to monitor during sleep only)

@dat just tried. It was discovered and connects - but doesn't do anything.

Do you know how I get started with it?

The journey of a thousand miles starts with opening an issue.

https://codeberg.org/Freeyourgadget/Gadgetbridge/issues/5193

If you've ever set up a new device on #GadgetBridge - I'll take any and all advice 😃

Holy shit! It worked 😁
I used #GadgetBridge nightly, I turned on the debug stuff, and added the unsupported P80 as the V89.

And it looks like most of the stuff works. I can track battery, change watch face, measure heart rate, see steps etc!

Oh, and even if you can't do deep coding - you can always improve the documentation.

https://codeberg.org/Freeyourgadget/Gadgetbridge/pulls/5192

Open source is about helping others in *any* way that you can.

Nice! Even without modification, #GadgetBridge can read this sub-£20 smartwatch's data.
Gets sleep, steps, and heart rate without issue. Seems pretty accurate - picked up my exercising just now.
Few missing bits like notifications (which I'll try to diagnose today) and some of the more esoteric settings.
Video: https://tube.tchncs.de/w/vYTnG6eKghnicdNj5nkhVx
Link to buy: https://s.click.aliexpress.com/e/_oCwt0hW
Full review tomorrow 😃

Ended up writing 2,400 words on this watch 🫢

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Here's the full blog post about this ridiculously cheap smartwatch.

https://shkspr.mobi/blog/2025/08/i-bought-a-16-smartwatch-just-because-it-used-usb-c/

@Edent
Thank you very much, I hope you are happy now. I've ordered the P80 smartwatch and also the P81 (no USB-C, but only 11€ 🤯, and slightly larger 300mAh battery). Will report if it works with #GadgetBride equally well.

@ge0rg @Edent thanks for sharing!
Is there any cryptographic key nonsense imposed by the manufacturer app? I want to connect it to Gadgetbridge from the start, without any other apps, does it just work?

@autkin @ge0rg
Nope! I literally just hit the pairing button in GadgetBridge and it connected.

(NB, I used the nightly build and had to manually add it as a different model number. But a change has gone in so the main app should be updated soon.)

@Edent
Got my P80 smartwatch today. To add it as a different model, you have to install gadgetbridge from https://freeyourgadget.codeberg.page/fdroid/repo/ and to long-tap the P80 in the discovery menu, then choose "add test device". Maybe you can add that to your blog?

The German translation is a mixed bag, the "Display" menu is translated as "show", some menus are easy to understand, others I can only guess.

Did you get contacts sync to work with GadgetBridge or only the original app?
@autkin

@ge0rg @autkin
It is mentioned at https://shkspr.mobi/blog/2025/08/i-bought-a-16-smartwatch-just-because-it-used-usb-c/#open-source-and-gadgetbridge

Feel free to leave a clarifying comment on the post.

I didn't try contact sync because I don't use it for calling.