Integration with Home Assistant

Hi! There's actually been some work on https://github.com/espruino/EspruinoHub which should allow it to integrate with Home Assistant (as a bridge to/from Bluetooth LE). The contributor didn't document it though and I haven't had a chance to try it yet.

My understanding is as long as EspruinoHub is using the same MQTT server, devices found by EspruinoHub should just pop up

Otherwise this works with Bangle.js and could be integrated with Home Assistant pretty easily: https://www.espruino.com/BLE+Node-RED

it appears that the watch is directly controlling the light. That is exactly what I'm looking for.

Well, that was actually done using this code: http://www.espruino.com/BLE+Lightbulbs

I never actually committed the app I used for that, but can do if you need it (although chances are you don't have those bulbs). I'd be happy to help with support for different bulb types if needed...