Hello,
After configuring my MagicMirror frame, I realized there is no straightforward module to establish a good connection with Home Assistant using its available features. Please take a look at the module I have been working on recently:
https://github.com/ambarusa/MMM-HomeAssistant
This module makes the MagicMirror available as an MQTT device automatically in Home Assistant, with the browser/monitor as a light entity, modules as switch entities, and sensors connected via GPIO as sensor entities. Everything happens through MQTT Autodiscovery, without needing to touch any configuration files in Home Assistant. This is what I really missed in other solutions like MMM-MQTTBridge.
Once connected, the possibilities for automations are endless and can be managed in the same place as other home automations. Once the GPIO pins are read and published, toggling the screen based on motion can be triggered from the central server, and this information can be used for other triggers in the house. This is what MMM-PIR is lacking.
So please have a look, give feedbacks and have fun with it!!