[wkjagt]

It would be cool if someone made a mass produced "watch" that's all the hardware but none of the firmware. So a tiny computer on your wrist that doesn't do anything out of the box, and you can make it do whatever you want. Maybe a watch, maybe something else. It just provides the housing, microcontroller, battery, screen, etc., and an SDK.

[matheusmoreira]

Sensor Watch. Open source replacement movement PCB for the Casio F‑91W and other similar watches. Open source firmware. ARM Cortex M0+ microcontroller that you can develop for using standard GNU toolchains. Battery lasts years. Temperature sensor makes it a temperature compensated quartz watch. They're even making custom LCDs now.

https://www.sensorwatch.net/

Wear mine every day. Contributed some improvements to the pulsometer and TOTP faces. Was even maintainer for a while. Really nice community. If you want something awesome to hack on, this is it.

[ricardobeat]

You can buy these from AliExpress:

https://nl.aliexpress.com/item/1005009235529767.html

https://nl.aliexpress.com/item/1005006734845748.html

[wvenable]

I believe that's the concept behind the PineTime.

https://pine64.org/devices/pinetime/

[wkjagt]

Ohh interesting! And pretty cheap too! Shipping to Canada is more expensive than the actual watch, but maybe still worth it...