An Open Source Smart Watch You’d Actually Wear

We’ve seen a number of open source smart watches over the years, and while they’ve certainly been impressive from a technical standpoint, they often leave something to be desired in terms of fit and finish. Exposed PCBs and monochromatic OLED displays might be fine for a trip to the hackerspace, but it wouldn’t be our first choice for date night attire.

Enter the Open-SmartWatch from [pauls_3d_things]. This ESP32 powered watch packs a gorgeous circular 240×240 TFT display, DS323M RTC, BMA400 three-axis accelerometer, and a 450 mAh battery inside of a 3D printed enclosure that can be produced on your average desktop machine. WiFi and Bluetooth connectivity are a given with the ESP32, but there’s also an enhanced edition of the PCB that adds another 4 MB of RAM, a micro SD slot, and a Quectel L96 GPS receiver.

The GPS edition of the PCB

As it’s an open source project you’re free to download the PCB design files and get the board produced on your own, but [pauls_3d_things] has actually partnered with LILYGO to do a run of the Open-SmartWatch electronics which you can pick up on AliExpress right now for just $24 USD. You’ll still need to order the battery separately and 3D print your own case, but it still seems like a pretty sweet deal to us.

On the software front, things are pretty basic right now. The watch can update the time from NTP using a pre-configured WiFi network, and there’s a Bluetooth media controller and stopwatch included. Of course, as more people get the hardware in their hands (or on their wrists, as the case may be), we’ll likely start seeing more capabilities added to the core OS.

While getting our own code running on commercially produced smartwatches holds a lot of promise, the Open-SmartWatch is arguably the best of both worlds. The partnership with LILYGO brings professional fabrication to the open hardware project, and the GPLv3 licensed firmware is ripe for hacking. We’re very excited to see where the community takes this project, and fully expect to start seeing these watches out in the wild once we can have proper cons again.

36 thoughts on “An Open Source Smart Watch You’d Actually Wear

  1. there are so many cheap watches now that i have to keep reminding myself that i don’t really want one. it’s too easy to remember how badly i wanted one before they were feasible! when i was a kid i loved my casio databank watches, and then later i adored the ruputer from afar. but now i’ve passed up generations of pebble and lilygo and so on simply because i can’t imagine what i’d use one for.

    but what i love about this one is the 3D printed link strap! wow what a hack! i clicked around a little but couldn’t figure out how the pins work. it kind of looks like they’re tiny hex head screws? i kind of want to imagine using cut-off small nails and pounding the tip until it’s wide but i have an idea that’s not really realistic. i could have a use for that kind of fastener / hinge in several other designs too so i’m really curious.

    1. i couldn’t stop thinking about it and i realized how i would do it. i would use a bit of steel wire (i have a bundle of fence wire) that is shorter than the full width of the link, and i would seal the ends with manually-applied PLA so the pin doesn’t slide out. i just do like “G0 E50 F50” and it dribbles out PLA for a minute like it was an over-engineered hot melt glue gun. to take the strap apart, i’d have to break the PLA.

    2. Hobby shops (remember those?) Often stocked small bolts, washers, and nuts in a variety of sizes. (By small, I mean Tiny)
      One use case was bolting Cox engines to airframes.

  2. What I’d like to see is a smart pocket watch. Ideally the outside of the watch would look like a Victorian-era railroad watch, and normally the display would mimic the appearance of such a watch, such that at a glance the watch would pass for a vintage mechanical pocket watch. However, it would still have all the *modern* abilities of a smartwatch.

    I’m guessing that a metal case would cause problems for all the RF-based capabilities of a smartwatch, though.

    1. I’m with you on that one. I don’t think I could get used to having a watch on my wrist again after about 30 years without, but I have a nice empty antique pocket watch case I got from a watchmaker friend years ago that’s been just waiting for something electronic to go in it. If you use a pocket watch case that has a glass front (i.e. not a “hunter” case that has the extra metal cover over the crystal) I’d think it could communicate through the front pretty well. I might have to try that…

    2. It seems like it wouldn’t be terribly hard to do this. Find an old (ideally broken) one and stuff some hardware like this inside. Heck that’s a pretty cool project. Time to go antiquing..

  3. I’ve been eyeing-off those tiny round displays on AliExpress for a while, but lack of documentation or even a reply from the sellers about a recommended video board for them has me leaving them alone.

    1. Until you need to know the time while in the company of a privacy enthusiast. I love my google alarm clock(Although I’d prefer all-local that doesn’t need a solid internet connection)….. But yeah…. Some people get super uncomfortable.

      Then again those same people probably hate smartwatches.

      1. Some people just prefer to be a on a leash. Nothing wrong with that. It how some folks will trade their privacy for shiny little trinkets. Just look at all the Alexa and NEST users. Or that hideous Apple smart watch. How Apple convinced people that cheap looking piece is something worth buying and wearing is beyond me.

      2. I have a bad eyesight. Not that bad, but without glasses I can’t read anything. That is why I learned to love the voice control. No fiddling around with my alarm clock or to get the time at night. Even possible when more being more drunk than usual.

        I like to hear radio while programming. Cheapest way to get all web radio stations and voice control my radio.

        Sure I have lots of privacy concerns, too. But if I would take it that serious, I couldn’t online-shop and need to pay cash only hidden in a full body bag, because shop cameras.

        I would switch to some 192.168.*-only solution, if any exists that works and costs less than 25 € a piece and is that hassle free like my Echo pucks.

  4. I saw this on Linus tech tips and bought one from Alibaba instead of putting it together myself (I shake too much and couldn’t manage some of the smaller components. There are two things that I think this project needs right now–on wrist notifications for email and texts, and vibration. I hope we can get those added.

  5. I like the idea, but how good is the actual runtime for normal use and a battery size that is still comfortable on the wrist?
    With commercial “smartwatches” like my MiBand going for 2 weeks without recharge, i think that should be the benchmark. Charging more than once a week is already a no-go.
    And it has two problems that keep me from getting it actually, first is the micro-usb port, as i’m trying to move forward with only needing USB-C (i just don’t want more than once charging cable on all my desks) and the second issue is that it’s not water proof. Would not want to take it off for every shower, dishwashing, or riding my bike in the rain…

    1. ESP32 has pretty good low power modes, and you can cram a pretty nice battery into a case. In the end it’ll depend what you want to run on the watch. If you just want the time you’ll get many days of runtime, if you want second by second GPS tracking you’ll get many minutes of runtime.

        1. From the datasheet:
          • ESP32-U4WDH (with a 3.3 V flash embedded): this minimum voltage is 3.0 V;
          • ESP32-D2WD (with a 1.8 V flash embedded) and other chips (no flash): this minimum voltage is 2.3 V;
          However, the max is 3.6, so there’s a regulator on board, that, if fed with 3.0V, won’t output 3.0V. The dropout voltage of the XC6209 can be as much as 0.53V so I guess you’re safe.

  6. Is there a similar device out there with a rectangular display?

    I’ve tried to read text on my round-display Galaxy watch. The problem is it has no awareness of the actual shape of the screen when it flows text.

    It has two display modes. In one it uses the whole screen by pretending it has a rectangular display as wide as the middle of the circle. So text near the ‘corners’ is cut off. In the other it zooms out, cramming the text into an inscribed rectangle and making the font so small as to be unreadable.

    I suppose with an open source watch it might be possible to code some sort of text box that is aware of it’s actual shape and word-wraps within the round area. But that sounds like a lot of work compared to just starting with a rectangular screen.

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