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Comment by athrun | Hacker News Reader

I was thinking of doing the same but IR control only allows for unidirectional communication with the unit.

Since there's no feedback mechanism, how do you solve for when the state of the unit(s) gets out of sync with HomeAssistant's?

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It just doesn't matter that much in my experience. If an issued command didn't work, it's easy to tell anyway (it's hot/cold), and you can just repeat it. HomeAssistant also has bits of special handling for items that don't communicate their state back, called "assumed state".

For the rare times I want to control my AC when being away from home, I have an air monitor nearby. I can just check if the temperature/humidity has changed, and repeat the command if it didn't work. If you _really_ cared you probably could script it to do it automagically, but I didn't feel the need to bother.

Yeah there’s very few edge cases, imo, where you need the feedback.

I have home assistant controlling an air conditioner in one room. (Well, mostly Node-RED.)

Every couple minutes it checks the temperature in the room and makes a decision on whether to call for cooling and tells the AC to turn on or off.

If it’s already on and cooling and it tells it to turn on… it’s a no-op, nothing happens. If it tells it to turn on and the command doesn’t go through… the room will stay warm so it will try the same thing in a couple of minutes. Same thing the other way (turning it off).

The remote has no feedback. I have found Tasmota IR 100% reliable over 3 years. It sends the whole state on every transmission so the IR has no receiver.

https://tasmota.github.io/docs/Tasmota-IR/#sending-ir-comman...

If the message sent over IR always contains the full state, then it's only a matter of checking that the message was received.

If you are in the room, you'll know soon enough, otherwise I guess it could be possible to rely on the audio feedback (a light beep) that the AC probably emits when it successfully receives a command. (and add a temperature sensor to check that it's working properly)

Not all state is necessarily transmitted over IR. For example, my unit has a button on the remote to turn the LED on or off; over the air this is just a toggle, only the AC knows which state the LED is in. (That said, that particular issue is easy enough to handle since changing any other parameter turns the LED back on, putting it back in a known state; there's no way to keep it off.)

AC is typically something you only need when you are inside the house so it is not like any freak situation would occur. If it happens only super occasionnally at worse you just set it the homeassistant state using the remote manually.

I guess you should hide those remote in a drawer and remove the batteries when you start using homeassistant

Similar problem here. I've thought of getting IR receivers to also listen for the remote's IR signal, since you have to be able to encode the IR protocol anyways. But even then sometimes the AC unit doesn't get the signal from my remote, so I'm unsure if that's a remote issue or receiver issue.

The completely overkill setup would be to get a different remote control, get my DIY receiver to accept that and convert it to my AC unit's IR code, updating HA while at it. The remote's state would be out of sync still, but it'll keep the units in sync with HA.

A lot of remote controlled air conditioning systems (like mini-splits and windows units) send the entire state of the remote via the IR blaster every time a key is pressed so there's no chance of the two getting de-synced.

For me the only way it can get out of sync is from power failure in the AC, or someone using the remote. Putting the remote away solves the last.

I have Zigbee contact sensors that provide on/off feedback to HA by detecting if the louvers are open.

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