alt Hacker NewsThese 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.
Replies
Would running the unit in Fahrenheit improve the sensitivity?
Is your unit one of the ubiquitous Midea rebadges? Or at least one where the remote does 'follow me' type periodic, remote temp reporting?
If so, you're right, the easiest way is to build/buy an IR blaster module for a microcontroller (ESP32 if you want wifi) and connect a temperature sensor. HA/EspHome is overkill for this, but can be useful for the large catalog of pre built integrations. Most of them are built using/on IR libraries for 'Arduino' anyway, so you can easily roll your own with a half dozen lines of C++.
Mapping out your own PID correction algorithm (esp says the room is 72 F when it's really 70 F to get it to cool sooner), but usually just having the remote room temp sensor near where you'd be sitting instead of near the ceiling or in the return air stream gets you close enough.