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Ask HN: A cheap smartwatch with a supported SDK

by 41209 on 12/11/21, 4:42 PM with 45 comments

• by denysvitali on 12/11/21, 5:13 PM

  Depending on what you mean by "smart watch": you can try the Pine Time: https://www.pine64.org/pinetime/

  51 USD will get you a sealed smart watch and a dev kit :)

• by azdle on 12/11/21, 6:17 PM

  The Bangle.js 2 just delivered to kickstarter backers: https://www.kickstarter.com/projects/gfw/banglejs-2-the-open...

  AFAICT, it's fully open source software (except, presumably, the nordic hal stuff?), with a JS SDK and a hosted IDE. But, I haven't used it yet because it requires WebBluetooth, and I refuse to use chrome, and I haven't figured out if the rasppi hosted IDE is still supported or not, it seems that the `nw` package doesn't support arm (anymore?).

  But this was the best option I found when I was looking awhile ago.

  The other things I considered were the Pinetime (software is still a bit too early from what I've seen) and "Paul's Open-Smartwatch" https://open-smartwatch.github.io/, but I really wanted GPS and that version's design isn't finished yet.

• by Jugurtha on 12/11/21, 4:59 PM

  I have worked for many years on fitness trackers from https://www.jointcorp.com. Talking with them, they sent PDF files for the communications protocol (Bluetooth Low Energy). I wrote a generic codec that consumes a YAML file and could decode packets from these devices to Python objects, and which could take a Python API call for a function you didn't write and encode it to binary packets the watch could understand. Practically, when we needed to use another device, I just added to the YAML file and the thing worked with practically no code change. New watch with GPS data? Just add to the YAML file and magic happens. Watch with blood pressure feature? Just add a few lines to the YAML file and magic happens.

  The code was on a Raspberry PI in which a 3G/4G dongle was plugged, and it connected to the watch, uploaded data, was robust do disconnection events either internet or BLE (used Thespian and the Actor model to create and kill actors). The devices were geographically distributed on different timezones (a fucking nightmare) and basically needed to work for users with zero technical skills. It needed to be plug and play and it just works. Even configuring the pairing between a Raspberry PI and the watch needed to be low touch (I used the analogy of a dog and a hand: you put your hand out for the dog to smell and recognize you, you put the watch nearby the Raspberry PI and it computed the RSSI and duration to detect the "intent" so it didn't pair with "drive-by" devices). Kind of like NFC, but for BLE. The data was sent to a backend, then displayed on a mobile application (the prototype had a Grafana dashboard that showed your activity in near-real time).

  Talk with them. They'll probably send you the PDF spec and you can do whatever you want.

• by palyancodr on 12/11/21, 6:21 PM

  Hi!

  Check out the watchX: https://youtu.be/AKSIGRdL-ts You can code it with Scratch or Arduino. There are a lot of examples available: https://community.watchx.io/t/watchx-watch-face-collection/6...

• by h4waii on 12/11/21, 5:48 PM

  You can still develop for Pebble, even though the entire thing is EoL. There are lots of Pebble enthusiasts and work is still being done on the platform through Rebble.

  There's also Bangle.js to keep an eye on.

• by jsilence on 12/11/21, 6:01 PM

  Maybe Watchy does what you want. No personal experience though. https://watchy.sqfmi.com/

• by diego_moita on 12/11/21, 5:29 PM

  You can find old Pebbles at that price at eBay[1]

  IMO, it still is one of the best smartwatches.

  [1]: https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m...

• by atemerev on 12/11/21, 9:24 PM

  There are many ESP32 smartwatches available on Aliexpress for about this price. ESP32 is compatible with Arduino IDE, PlatformIO, and many other development tools.

• by alistairjallan on 12/11/21, 7:36 PM

  The Lillygo or TTGO watches you'll find on AliExpress support Arduino libraries, Python, C or even JavaScript.

• by sorenjan on 12/11/21, 8:51 PM

  > Looks like Google is coming out with Wear OS 3 soon

  Wear OS 3 is already out.

  https://www.androidauthority.com/wear-os-3-watches-2736393/

• by sokoloff on 12/11/21, 5:13 PM

  I picked up a (used) Series 3 Apple Watch for $100 early last year. If you got one of those, it’s surely going to be worth $50 in 12 months.

  I’m in the Apple ecosystem and very happy with the watch, even though the newer versions are surely nicer.

• by evan_ on 12/11/21, 8:23 PM

  See if you can find a Timex Datalink on eBay

• by seniorivn on 12/11/21, 8:10 PM

  pinetime