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Comment by mmoskal | Hacker News Reader

I wonder what the battery life. ESP32 tend to be very power hungry with WiFi, not sure about pure BLE operation. This is why simple long-lasting (eg Withings, misfit) watches use nrf52 chips.

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I suppose you could put it into light sleep mode (0.8mA) or deep sleep mode (<0.15mA) most of the time, and only switch on the Wi-Fi/BLE occasionally to sync data or when the user wants to interact with it. You could also use the hibernation mode (0.005mA) at night, and set up an RTC timer to wake it up in the morning.

I do like the idea of a fully open source watch though, I used to do quite a bit of Android Wear development in its early days [0] [1] [2] but got frustrated with Google breaking my apps every 6 months with new APIs, breaking my Android Studio projects with every new version of Android Studio, and removing them from the Play Store because of new rules. I much prefer hardware and software that just continues to work if you do exactly nothing, which is kind of how all my other appliances work. It's not like my air fryer or rice cooker just stop working if I don't update their software.

Also I absolutely hated Java and would much rather develop in C++, (Micro)Python, or even C, all of which are possible with the ESP32.

[0] https://www.pcmag.com/news/attopedia-for-android-wear-puts-t...

[1] https://www.androidpolice.com/2014/07/15/there-is-now-a-matr...

[2] https://www.androidauthority.com/android-wear-remote-app-404...

Not that the experience is that memorable, but wearOS does support the NDK.

Yeah but you still have to package up your app inside a piece of Java shit, have 70+ gradle files that break at every new release, sign your package, zipalign (what the actual fuck, the OS should do that) your package, ...

I mentioned C/C++/Python because the actual app would be much simpler and less bloated, not because of writing inner functions in those languages.

Actually I would apply that adjective to Android Java, Google's own flavour of J++, and the NDK as whole.

It is incredible how NDK manages to make me miss Symbian C++, so I get your point anyway.

“ The battery life SQFMI estimates depends on your use case — it says if you’re just keeping time you should get five to seven days, but if you’re fetching data frequently you may only see two to three. Its open-source nature, however, means that you could always fit a larger battery into it, or try and make some software optimizations if there are features you’re willing to cut.”

From the verge review

I've gotten 2 days of constant use, and it's hardly dropped voltage at all, will likely last 6. The eink screen uses no electricity between screen updates, and the stock firmware turns all peripherals off when not in use.

I've been entertaining myself basically learning some embedded programming on the watchy.

I've got mine only waking up once a minute using the external RTC as a trigger. In between I put it in hibernation (~2.5uA to the processor). So every minute it's waking up for about a second to do some updates, redraw the screen, and shut itself back down. (It takes quite a while to refresh the screen.)

I haven't had it unplugged more than 24 hours at a time (keep plugging it back in to do some more programming and debugging), but so far the biggest drop I've seen was the battery voltage (rounded to the nearest tenth of a volt) going 4.2 -> 4.1. Even assuming worst case rounding here, that's something like 100% -> 95% battery capacity, so I'm looking at more like 20 days just doing basic time keeping so far.

Something between 2 to 7 days, see https://watchy.sqfmi.com/docs/battery-life

Quite disappointing. They're comparing with Pebble OG, but I owned both a Pebble OG and a Pebble 2. The battery life of the former went away with the OS update to the OS version on v2, but the 2 lasted easily for a week, and it looked better IMO. The HR is like RNG, and the case eventually deteriorated (and I sadly failed to replace it with), and of course the support did not last long.

I now use a Fossil HR Collider. It lasts for 2 weeks probably thanks to e-ink. The HR also isn't useful, but it looks good for a round watch (except for the stage light) which you can make look like a normal smartwatch, and it can control e.g. Spotify and weather. I don't need much more on a smartwatch. The only thing I miss is the ability to put Bluetooth off.

Fossil HR Collider is 4x the cost at least and is a commodity fashion accessory, this is a hacker toy. One should adjust their expectations accordingly ... I agree they should maybe compare to a defcon badge.

The list price was $200 at launch but they’ve run sales quite a bit. I got one for $120 (and returned it 2 weeks later because the buttons were hard to trigger and the UI wasn’t intuitive for me).

Good thing my Pebble is still ticking!

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