Active BLE connections within Home Assistant?

I've just made some tests with BTHome and Home Assistant as covered by excellent videos from @Gordon:

Video1
, Video2

BTHome uses BLE advertising to send sensor data to Home Assistant (uplink). Now I would like to play with "actuators" which needs downlink. I was thinking of:

• displaying data on a Pixl.js
  
• Toggling relays on Sonoff devices (running Espruino of course)
  
• doing PWM outputs
  
• ...
  I suspect in this case the best bet is to integrate EspruinoHub into Home Assistant. So far so good, except I have installed a Raspberry PI with Home Assistant OS and I don't have access to the RPi system to install EspruinoHub. (HA OS is running into a Docker and you don't have access outside of it, AFAIK)
  
  
  

Any ideas out there?

Yes, I've been feeling like I really wanted to do something like that as well.

Home Assistant's use of built-in BLE or ESPHome devices is really neat so that would be best to use if possible though - I have several in my house now to get coverage throughout, and it does support making connections.

BTHome itself doesn't support connections, and I did ask the author but he's not interested in implementing that at the moment.

I really wanted to make a Home Assistant 'integration' for Espruino that allowed you to effectively just associate endpoints to function calls, so it'd connect to the UART, write "setX(0)\n" and then disconnect, but I haven't got around to that.

It looked like it wasn't too hard though - afaik HA uses an API that's basically 'Bleak' so you could take the code from https://www.espruino.com/Interfacing#pyt­hon, dump it into an integration and it'd work. The issue was really just making sure it had a nice interface so you could add/configure devices

Thank you for your detailed reply.

I had a look at built-in BLE and I am not sure it is that easy to integrate actuators, especially proprietary BLE profiles, when SIG-defined profiles are not sufficient.
I will probably have a try with ESPHome BLE relays, it seems that at least connection oriented communication would be possible. Not sure however how to deal with the application level.
I agree that it would be great at some stage to provide an integration into Home Assistant. As I am playing with it those days, I will try to get my hands on a custom integration and see where it takes me. I will post here progress, if any.