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Comment by abetusk | Hacker News Reader

Wow, this article doesn't do it justice.

Watchy is an open source hardware device that uses an e-ink display and has an ESP32 module builtin [0].

SQFMI, the creator of watchy, has a twitter account [1] which has some very nice screenshots [2] [3]. Even the CrowdSupply website has better pics of the device [4].

This is one of the few watches I've been sorely tempted to buy.

[0] https://github.com/sqfmi/Watchy

[1] https://twitter.com/sqfmi

[2] https://twitter.com/sqfmi/status/1351647180382228488

[3] https://twitter.com/sqfmi/status/1357177624523661315

[4] https://www.crowdsupply.com/sqfmi/watchy

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There is also a new Watchy community on Discord here: https://discord.gg/uKcfZZa2

For those considering purchasing - as a Watchy owner - if you're looking for a polished smartwatch product that you can put on your wrist and not think about how it works - this isn't that product. It's still rough around the edges, uploading new watchfaces takes some work, phone notifications aren't implemented yet, no case, etc.

But if you're intrigued by the idea of hacking on ESP32s, WiFi, BLE and/or e-ink, as a wearable hackable dev device, Watchy can't be beat. It's a lot of fun. Think of it as a wifi/BLE-enabled Arduino on your wrist.

How's the battery charge duration?

It will vary greatly with the watchface and whether you use wifi (weather, ntp, etc). In the current implementation it will do a full connect every minute so there's room for easy improvement. With wifi I get about 48h out of it.

The ESP32 is known for being cheap and featureful. The downside is that some functionality is implemented in software which results in lower battery life.

With my custom watchface I built, I sync ntp and weather every hour. I get about 100 hours of battery from it (4+ days).

e-ink is a company, it's a Active Matrix Electrophoretic Displays (AMEPD).

Are there any other companies besides E-ink Corp that sell ^AMEPD^?

Yes, the people who make the Watchy display seem to, https://www.good-display.com/product/6/

Except for e-ink, why should I buy one, instead of this "polished" one:

http://www.lilygo.cn/prod_view.aspx?TypeId=50053&Id=1290&FId...

(i need a new gadget to play with, a watch seems a 'fun' choice, not affiliated with anyone, I just order a bunch of crap from aliexpress)

Watchy is open-source hardware: https://github.com/sqfmi/watchy-hardware

BOM: https://github.com/sqfmi/watchy-hardware/blob/main/WatchyBOM...

The link isn't loading for me, but I'm assuming that's a TTGO. Also a cool device & a good choice too, but as others mentioned Watchy has placed a high priority on docs, community, and open source - TTGO is more like "here's some hardware good luck". Plus, the e-ink screen just speaks to me :)

This isn't polished either, I have one and it registers phantom touches all the time, keeps vibrating, actual touches don't register, etc etc. It's not really usable, I left it in a drawer ten minutes after opening it.

Very disappointing to see an "open source" project locking their community behind Discord. Why not IRC, XMPP, or Matrix?

Worth noting PineTime is a similar device and they're reachable on IRC and Matrix.

Oh wow. They should choose a different image. I looked at that and thought it was using an actual segmented LCD display, not an eInk display simulating the look of a segmented display.

You just pushed me over the edge, ordered a couple just now (I started always ordering 2 of anything somewhat “experimental” so I can mess around with one while making actual use of the other), looking forward to playing with it :)

Are there files somewhere for a 3D printable case for it? Such as something you could do on a $300 consumer-grade printer capable of ABS filament printing?

Yes there is something https://github.com/sqfmi/watchy-cases , but join the discord, cases are very actively being developed.

Are there any videos? [2] is a video but only 5 seconds long and demonstrates 1 small change on screen. I was wondering if e-ink screen suffers the same problems other e ink screens such as ebook readers

The screen supports incremental updates which are pretty fast, so you don't get the full flash refresh every minute. But yeah, it's not "video" fast, it's still the same old e-ink technology with all its pros and cons - you still have to do full screen updates sometimes.

Can anyone find any specs on how long the battery lasts?

The ESP32 is a pretty serious power hog...

ESP's only a power hog when it's using the WiFi... In deep sleep it can go as low as 10 uA! .15mA gets you the low-power processor for doing sensor interrupts.

In reality Watchy currently draws around 1mA while sleeping and 55 hours of battery for me, not using WiFi (not really a priority for me).. I think that can be improved with firmware updates, seems like there is potentially some low-hanging fruit. It's all open source firmware, so you can eg. program it to deep sleep while you deep sleep to save battery :)

That is a power hog, compared to say an STM32L4 with, per spec, ~250 nA deep sleep w/ RTC & some RAM (to make it at least somewhat comparable to the ESP) and 50uA/MHz dynamic run mode.

Also you shouldn't just take steady state values. I've had various ESP's on a power analyzer. They take a bit more (like 30mA for many msec? iirc) for a while during wake up (w/ wifi off) before the consumption drops to the final value. For example some of that goes into uncontrolled/undocumented oscillations on some pins (for up to 100ms?), thought that is probably a negligible part.

ESP's are only popular because they're the cheapest/easiest option with WiFi. At least that's why I use them...

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