HeatPump VS esphome-mitsubishiheatpump

I think we are talking about different machinery (or maybe different levels of control). What I meant is something like https://github.com/SwiCago/HeatPump , but officially supported.

SwiCago has references for hardware to buy (I used this to get the premade pig tails)

I have four of these units. Not sure of your tech comfort level, but I didn't want to pay $200+ per unit for the Mitusbishi thermostat, so I got some ESP32s and programmed them with this library. Now they're fully controllable using my existing Hubitat setup and a driver I wrote.

Brought them all into Home Assistant using ESPHome https://github.com/SwiCago/HeatPump

Nice, I'm also using Unifi NVR. For thermostats I use ZigBee temp sensors and built ESP32 boxes to control and give the temps to air handlers using swicago -- no actual thermostats on the walls. For sound I'm using Chromecast Audio for sources and proper amps/speakers. Unfortunately for shades Lutron has the best, which means dealing with their proprietary junk. If you can get the QS processor they are phasing out, you can use telnet (called LIP) to control it. Otherwise with QSX they've made it impossible for DIY, it's undocumented and unnecessarily complex in the name of security -- security I do not need on my secure LAN. Lutron also has nice motion sensors and (Palladiom) keypads, but I don't use them for lighting, ironically. Other shades like Somfy may be good enough at a fraction of the price. For circadian lighting, if you end up going the ZigBee route and forgo full color, the adjustable white Hue bulbs are cheaper. Savings can add up if you'd doing a lot of bulbs.

If you don't want to use the cloud, you can directly interface with the minisplit: https://github.com/SwiCago/HeatPump

DIY Plug in: this Github Project describes a way to diy a plug in connection running on ESPhome for a few $ of parts, but I'm a bit of a novice and don't know how I would connect this to Homekit.

If you Home Assistant or ESPHome, this is the jam. https://github.com/geoffdavis/esphome-mitsubishiheatpump

Highly likely you're experiencing a watchdog error on an idle core. The only way to know for sure is to enable logger, which will be a challenge here. You can see an example here., but this is a widely reported and poorly understood issue.

If you can add homeassistant, you should look at https://github.com/geoffdavis/esphome-mitsubishiheatpump -- we're using it with 5 split units. It works great, is faster than infrared, and cheaper than the wired or wireless control options from Mitsubishi.

If your Mitsubishi uses IR for it's remote, this probably would work: https://github.com/geoffdavis/esphome-mitsubishiheatpump

Or, you can use a Broadlink IR blaster to clone the remote.

If your heat pump talks to MEL cloud (Mitsubishi's cloud thingy) then this should work: https://www.home-assistant.io/integrations/melcloud/

I have yet to buy a "smart" device that I haven't been able to control through HA. The Broadlink RF/IR bridges even makes anything with a remote automatable.

Seriously, If it wasn't for Home Assistant, the "smartness" of smart devices would be next to useless.