05 / Connected wearable
ZetaWatch
Custom watch firmware and an Android companion built around a real device and power budget.
THE QUESTION
What does a useful, repairable personal smartwatch look like when you control both ends of the connection?
THE APPROACH
ZetaWatch pairs ESP32-S3 firmware with an Android app for notifications, time sync, voice interaction through Home Assistant, media control, alarms, and firmware updates.
DESIGN DETAILS
- The phone handles connected services while the watch owns its display, controls, audio, and local state.
- Firmware updates write to an inactive slot and use image checks with rollback support.
- Power, motion, and wrist behavior are treated as physical validation questions, not just build results.
CURRENT EVIDENCE
The README separates implemented features from wrist testing still needed for step accuracy and lift-to-wake tuning.