Mitsubishi Air Conditioner Remote Control

Hi there,

I have a mitsubishi heavy air conditioner with classic IR remote controller and Broadlink RM Pro unit.

Is it possible to control this AC via RM Pro? I’m not just talking about turning on and off. Set temperature, set fan speed etc…

Thanks in advance

The ROM Pro can only mimic the button presses, it will be up to you to write automation code to do the underlying functions that call each button press a number of times to correctly make HA mimic the underlying functions of the buttons, if you see what I mean.

My understanding it’s not possible to send exact key press number of times. Because we dont know last status of AC (temp, fan speed, mode etc) So I do not know how many times I will hit the button.

I think remote controller send same code to AC for each key pressed.

Let me check with broadlink learn mode in HA.


I think problem solved. Single key is sending different code to AC. After loop end. Send same code again.

Problem solved :slight_smile:

Glad you have it sorted :wink:

But is it possible to control Mitsubishi AC over HA? I am planing to buy one myself (with wifi module).

Yes. HA can control Mitsubishi Climate via Broadlink IR Unit. But learning mode little bit nightmare. Because standard remote send all status code at once.

For example if your climate state “cool” “21C” and fan speed is “low” in AC remote and grab this code for feature use, HA send this bulk code to Climate. You can not change “only” temperature or fan mode. If you change temperature to 23C, And fan speed to medium, you need to grab all IR combinations. “Low, cool, 21” “low, cool, 22” “high, cool, 21” “medium, cool, 21” etc.

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It is possible to control it directly and with more control than any of the commercial offerings if you’re willing to get your hands a little dirty. Unlike IR control, you can read the status of all of the settings as well as change them. You can also set an external temperature if you want to use your own sensors to provide a better reading over larger spaces. (I have mine set up to use temp and occupancy sensors to do a weighted average based on occupancy in the living room/loft space of one of mine).

You can wire up an ESP8266 (such as a Wemos D1 Mini or similar) to each head unit to get control over wifi via MQTT.
It requires a custom connector to wire up, but it’s a relatively simple job. You’ll spend about $4-7 per head unit you want to integrate on parts (which beats the $150+ you’ll spend per unit for official offerings). Keep in mind, you’re wiring up to the same connector that these things use, but if you do it wrong, you’ll likely burn out the ESP8266 and could even damage your heat pump. That said, these are also smaller than the commercial wifi unit that hooks on the outside. Mine are completely hidden with no wires.

I did this on mine with no problems a few months ago and I couldn’t be happier. If your unit supports “wide vane” mode (oscillating left and right), that’s not available through the default HA climate panel. You can modify the climate panel to support it, it’s a bit of work to plumb through. You can also just make an input selector that sends mqtt commands which is really easy.

Thanks to these guys, there’s code and documentation of their reverse engineering of the protocol, as well as a custom component for HA :


Great news, thank you @ScottD

I looked at AC’s motherboard to try it now, but unfortunately I did not have that socket for WiFi support in my Mitsubishi AC model. I will continue to use it with Boradlink RM.

Thanks again!

As fas as I know, this CN105 port is located only in Mitsubishi Electric devices. OP’s is Mitsubishi Heavy Industries which, albeit the similarity in its name, is a completely different company (they splitted in two a few decades ago).


My AC is Mitsubishi Heavy.

Bummer, I did not realize they were totally different manufacturers. Still, perhaps that information will be useful to others looking into this subject as to what is possible on each brand.

Great, i will use with my AC

Hi all,

I just finished working on a first Arduino version for controlling Mitsubishi Heavy Industries (MHI) aircons over serial, inspired by the work of Hadley Rich and SwiCago. I have successfully used the CNS connector on the MHI’s PCB (the equivalent of the CN105) in combination with an Arduino Pro Mini and ESP-01 for WiFi. The communication protocol is completely different and unfortunately more complex than that of the Mitsubishi Electric units.

In the current version, communication is bi-directional and it’s possible to set the mode, power state, setpoint, horizontal vanes (for now) and fan speed via WiFi/MQTT. Ambient temperature of the aircon is also updated to MQTT.

I’m very interested if others can get this working also and help improve on the system and code:



Cool ! I have a broadlink mini, no one would have done the learning for the broadlink-ir-climate-component? I have the same remote control as in the photo. Otherwise I will try MHI2MQTT, pity that it does not work with a esp8266. Unless…? Thank you

You can also use a Sensibo Sky device to control a A/C

It was my wish to have it working with just an ESP8266 (ESP-01) too.

The problem is that the communication is SPI and I could not get an ESP8266 working as a SPI slave. In contrast, the ATmega328p-based Arduino’s are very easy to program as SPI slave.

If we want ESP8266 we need someone really savvy at this. I’m not saying it is impossible…

Hi @rjdekker, I responded to your open issues on your git for heavies, a few months ago. Have a look, maybe it will help you with esp01 only control.

Hi @rjdekker, I’d eager to repeat your project, but face some issues. I have aircon Mitsubishi Heavy SRK28HJ /SRC28HJ. It really has a CNS connector, BUT with 6 pins, not 5. The 6th pin is grounded. Other 5 are connected to IC D780022ACW NEC. Looked at the datasheet for connections: P67/ASTB, P66/WAIT, P65/WR, P64/RD, P74/PCL. I am not sure if those correspond to the ones you have specified in your description. Any hint wound be higly appreciated. Thanks.

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Hi, I own a split system, Mutibushi electric mxz-2c20na2 Mitubishi electric mxz engineering info

I looked at the manual you had attached (thanks!) and a bit of googling. I think I am looking for the cn105 port so I could implement this solution However, I can’t seem to find it. Could you possibly direct me to where it is for the 2c20na2 model? Or where it is in the manual you attached? (I assume I am just missing it?) Appreciate any pointers. :slight_smile: