alt Hacker NewsI added a non-wi-fi Mitsubishi AC to Home Assistant
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Mitsubishi AC units that support M-NET have a CN105 port. IIRC, my specific model uses a JST PA 5-pin connector rather than a JST PH 5-pin.
As a small hack, I used the Python scripting interface in Home Assistant to replicate this [1] feature from Panasonic HVAC that gradually raises the cooling set point towards the morning. It is quite comfortable during the summer.
[1]: http://getnavi.jp/appliances/681340/ (ja)
These mini split inverter units seem to be good for +/- 1 C, but the 2 C swing can feel quite substantial.
PID control seems to be lacking overall, the control laws seem to be more basic. In particular, my unit waits until temperature deviation from setpoint exceeds 1C before cycling on. If I want finer control, there are a few options I can think of: 1. Spoof the temperature, add a TEC , heater, cooler or something to the sensor on the remote 2. Manipulate the controller buttons, change the setpoint down or up by 0.5 degrees so the unit kicks on after a 0.5 degree change instead of a 1 degree change 3. Spoof the temperature sensor itself, hack into the wiring with some transistor based circuit 4. Hack into the actual unit, fully take over the compressor and fan control 5. Buy a better unit or off the shelf controller 6. Spoof the remote control, reverse engineer the IR communication temperature signal
This last option seems the least intrusive and cleanest, I see other people have done it, it's definitely a lot of work even with AI.
If anyone is looking for something similar it's worth looking into A somewhat less complex solution that preserves all functionality. Use the IR receiver plus a broadlink IR Hub. You can meet all the goals here, run it all locally the only downside is no 2 way communication. So if you do change the thermostat via the wall it won't be reflected in your app.
I did a similar thing, heavily aided by Claude, after seeing the protart modules posted here on HN last year. https://github.com/samstevenm/minisplit-local-public
Apologies for the Claudish, especially if anyone wades through the blog posts. I cringe when I reread them, but having some documentation on a working system is better than the ~none I was publishing before.
I've done this exact mode on my Mitsubishi ACs. Despite being old units that came with the house, they are instantly responsive and report back current temperature flawlessly.
ESPHome device are consistently faster and more reliable than any smart home tech I buy at 10x the price (not hard with $3 boards).
For anyone wondering why he would ever do this, it seems to be a type of hidden mini-split system used in euro-style shoebox flats, with a super-proprietary thermostat. Wi-Fi capability is an option at additional cost, but was not purchased.
In the USA, wired thermostats tend to use standardized 24V wiring schemes, or 208V/240V for mains voltage heaters (electric heat, common on the west coast, especially in shitty apartments, central hot water/steam heating with 24V controls is more common on the east coast).
I've been using mitsubishi2MQTT with Home Assistant. It's been working great for several years. https://github.com/gysmo38/mitsubishi2MQTT
https://archive.is/KF0iH (no annoying popups)
My idea of HVAC is that it should be "set and forget", so "smart" is the polar opposite of what I want. The round Honeywell on the wall has been doing its job for the past few decades, and will likely last many more with only an occasional cleaning.
Does anyone know if this could be used to "cap" the AC settings ? It could be useful in an airbnb place, where I want to limit the lowest (e.g. 18 degres Celsius) or hottest (e.g. 22 degres Celsius) the guest can set the AC.
Anyone tried this on the Bosch units? Their WiFi module comes as an addon too.
This is kinda unrelated but I learned while researching for my new AC that there are two Mitsubishi brands/companies, one is Mitsubishi Electric and the other is Mitsubishi Heavy Industrial. And their ACs are not the same, so just saying Mitsubishi AC probably could lead to problem. The one OP has is Mitsubishi Electric by the first photo.
I did similar with our coffee machine a year ago - I was bored of getting home from the school run to a cold pot of coffee because the machine automatically turns off the hot plate after 30 minutes, and it seems there is no such thing as a WiFi connected drip coffee machine. Kettles, yes, coffee machines, no.
Dead simple. Cracked it open, chucked an ESP32 in there connected to the soft power button, and to the “machine is on” indicator on the display, which was conveniently on its own pin. No need for any thermal protection cleverness as the machine does that itself.
Now I just turn it back on when I’m heading home, and no longer have to wait for the pot to warm up again.
I then decided to stop using the “make coffee at time” functionality baked into the machine, as the kid gets up when the kid gets up, and the machine would either start early and wake her, or she’d get up before it and I’d have to go start it. Now, she opens her bedroom door, I get “kid is awake” alert on my phone, and the machine brews the coffee.
I'm hoping to get a mini-split system installed soon and thought I might as well look for something with HA integration. It's not easy. Some manufacturers like Samsung actually want to charge you monthly for cloud integration! Completely out of the question obviously. I came across this, and Mitsubishi is supposed to be good anyway. I would prefer something that's actually supported but I can't seem to find any other options.
I could also very easily wire my units in so no need for WiFi. Maybe I can find a wired ethernet module.
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my solution is to capture the irs with flipper and replay them with tasmota
I’ve been working on a similar setup using the M5Stack NanoC6 and AtomS3 Lite, and put together a parts list and wiring guide on my site: https://serin-labs.com/parts.html.
I also built a web flasher with firmware configured for those boards, so you can install directly from your browser without any fiddling or configuring. The ESPHome option uses the same echavet/MitsubishiCN105ESPHome project mentioned in the article. I also included a YAML generator for that project so you can more simply customize the config. There are also separate firmware options for HomeKit and Matter. https://serin-labs.com/flash.html https://serin-labs.com/esphome/generate-yaml.html
I run Serin Labs and sell assembled kits and the cable separately.
For anyone with City Multi, P series, or M series systems with a branch box, you may also be interested in a multi zone controller I’m developing: https://serin-labs.com/multi-zone-controller.html. It connects to the system’s communication bus, allowing one device to control all zones without needing a CN105 adapter at each indoor unit. It also exposes operating data such as refrigerant pressures, temperatures, power, compressor frequency, and fault codes, with everything running locally. Software is still in development.