Apple watch as a physical interface to my Onkyo TX-L20D amplituner.
- Turning the AV receiver on/off
- Volume and bass level control via digital crown (satisfying haptic feedback)
- Switching between profiles (presets of audio source, default volume, default bass level, max volume)
A simple go program implements onkyo-eiscp protocol and serves JSON-based API for the watch app.
Special thanks to onkyo-eiscp for sharing the protocol details.