Zone controller

[flacco54]

Hi All,

I was going to install a few MHI split systems throughout my house, but the cost was prohibitive, and the power circuits required we couldn't accommodate. So we committed to installing a ducted Mitsubishi unit. I did plenty of research and found out that if I purchased the zone controller, it has the plug for the Wifi adapter using port CN506 which apparently has the same pinout and information flow via TX/RX as the CN105 used on split systems.

Here is the zone controller: https://www.mitsubishielectric.com.au/wp-content/uploads/2022/03/Installation_Manual-Zone_Controller_IM.pdf

The unit is being installed next week. I am confident we will be able to turn the unit on, set temp etc via the CN506 port. What I am wanting to know is how do I go about discovering how to turn zones on and off? Temperature is not set per room, so all the basic controls should stay the same.

I have some experience with ESPHOME, and played with ARDUINO a few years ago, but it is not a strong point. I have plenty of ESP32's floating around and the right cables to make the connection.

Is anyone willing to assist?

[SwiCago]

@flacco54 ,
Cost of zones system I could agree with, but number of circuits needed??? Did they quote you more than one outdoor unit? In my case I am running an 8 zone outdoor unit and have 6 zones inside. The outdoor unit powers each indoor unit and the entire thing runs on a single 30A circuit, which is pretty standard for residential AC systems.

Anyhow, on to your question. If this project is able to connect to your zone system and you can send on/off signal, you can enable debugging and watch clear as day HEX packets that are sent and received by the ESP chip. You can then tell the unit by other means which zone to activate and watch the packets received and see which byte changed. Then deactivate zone and see if that byte that changed, changed back again. That will at least tell you what is received as a confirm. As for what is sent to turn a zone on/off, you will either have to guess which command packet and which byte needs to be sent. YOu can send custom bytes. Generally a receive group will have a corresponding send group.. ex FC 42 is counter to FC 62 group of packets see #39 for some help decoding packets. Cleanest way to figure it out, would be to use a ESP32 as a relay and connect an official device to esp32 and esp32 to Unit. What packets between each and see what changes. Other way is again an official device and a logic analyzer.

Good luck. If you find the magic bytes and it does not disrupt current repo, you could make a pull request or add to #39 what the magic bytes are.