alt Hacker NewsThere are only a few features I care about in a smartwatch:
1. O2 monitoring. I have sleep apnea and live at high altitude, so this matters to me.
2. Motion sensor. Also mostly for tracking sleep.
3. Vibrator for notifications.
4. A screen backlight.
5. Battery life longer than a week.
6. Waterproof enough to survive a splash in the shower/rain.
I consider GPS, cellular, AI, touchscreens, cloud-only sync and control apps, and just about everything else to be anti-features. There are no devices that really cover all this that I've found. A few Garmin and Amazfit/Zepp devices come close, but they have enough drawbacks for me to not be happy with them. The new Pebble is nearly perfect, but the lack of an O2 sensor is a dealbreaker for me :(
The Sensor Watch circuit board [1] inside the case of a Casio F91-W / A158W / A159W satisfies 2, 4, 5, and 6. Accelerometer or thermometer available as daughterboard. Battery life measured in months, if not years. Although the simple LED backlight and the segmented LCD leaves a bit to be desired, and there is no wireless connectivity for notifications. Open source firmware.
The Ollee watch circuit board [2] is similar, better backlight but closed-source firmware and configuration over BLE in a smartphone app. Still no notifications over BLE though.
I'd think combining 1 and 6 (O₂ monitoring and waterproofing) would be difficult.
[1]: https://www.sensorwatch.net/
[2]: https://www.olleewatch.com/