HeatPump VS P1P2Serial

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

This? https://github.com/Arnold-n/P1P2Serial