Hi Guys, a while back I created a library for the ESP8266 chip to control mitsubishi heat pumps via serial connection its cn105 port.
The library is in C++ and in theory can be used by other micro controllers that have a serial port. I used it for the ESP8266 and used simple Arduino sketches to control the HeatPumps, using the library. A few others have helped discover new things along the way and we have created sketches from a simple sketch to a full blown MQTT sketch. WIth the MQTT sketch, you can use any automation software that supports MQTT, openHab for example or use the example we have for home-assistant.io
We also recently cracked how to send remote temperature to the heatpumps, useful for attic mounted ducted units. It is in a test branch, but will soon move to the master.
In anycase, we can currently do more than the MEL Cloud, KUMO Cloud or MHK1 device and it does not depend on any cloud service, making it more secure.
Here is the Git Hub link, in case any of you are interested. It has a intial page, with schematic and part links for ordering.