- You can start with MELcloud. You can control the essential stuff. Maybe that’s enough for you? See Mitsubishi MELCLOUD integration with Home Assistant.
Or you can go with the procon way. You need a Procon A1M melcobems mini (you can find it on ebay.co.uk sometimes), a modbus RS-485 adapter to USB (something like this) or to a ESP32 (example). - You can only connect one device so you need to chose between the wifi module or the procon.
- I have it working but I don’t have the spare time to help you in that way. You can find the esphome code in the link (5) in the first post.