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Comment by paranoidrobot | Hacker News Reader

I installed AC in my home in the last year.

I specifically went for units that were IR controlled rather than any proprietary smart B.S.

For the smarts, I used cheap IR blasters from AliExpress and hooked them up to HomeAssistant.

I just mounted cheap Lenovo tablets to the wall to do the room-dashboard thing to allow controlling lights/AC without a phone.

These kind of horror stories only serve to reinforce my decision.

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Some units have a 5V UART port that's easy to connect to HomeAssistant and has two-way communication: https://static.xtremeownage.com/blog/2023/pioneer-mini-split...

I did something very similar with my Pioneer minisplit. but i used this esp module you can just buy. Super simple and cheap:

https://smartlight.me/smart-home-devices/wifi-devices/wifi-d...

https://www.youtube.com/watch?v=f6GEfzVhwCE

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?

(not OP)

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).

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.

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.)

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...

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

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.

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.

I got the Daikin for the same reason. You have to pay extra for a wifi module but after reading the reviews on their app, they mostly said, it kinda worked but largely useless.

I built an esp32 IR sender and put Tasmota IR on it. It has first class support for the Daikin. It can't receive but it seems no need as it's 100% reliable.

For Daikin, https://github.com/revk/ESP32-Faikin works well, and is tidier (and I think more featureful?) than an external IR port. Its existence is why I bought a Daikin!

I have a lennox heat pump in my house and the main thermostat controller went out a few months ago.

Lennox uses a proprietary system like this one but the old school controls were visible on the control boards and due to a freak accident when an installer was levelling the floors for new flooring and cut the old wire I had a 5 wire thermostat wire installed instead of the 4 wire it came with.

Perfect.

$50 thermostat, wired it in. Powers on. Fan powers on. A/C condenser? Nada.

Official replacements were $700+, upgrades were $800.

Checked around, found an offerup seller selling the upgraded model for $400. Deal.

Met the guy, he gave strong, "I stole this, don't ask too many questions" vibes at first glance, and I was about to back out of the deal, but something clicked in my gut and I went with it.

Got it home, wired it up. Fan turns on. No AC. @#$@!#$%@#$^

On a hunch, went outside and checked the power for the heat exchanger. I had unplugged it for safety reasons but plugged it back in afterward, but gave it the snuggy test just in case.

Sparks shot out as it re-engaged. It's Alive!

The $50 one might have done the job, but no point in re-rewiring the whole shebang as the money is already spent.

If this system goes down, I'm going mini-split ductless. Forget this noise.

This is the way. I'm buying stupid tech exclusively, and make it smart in my own terms.

IR is fine for these things, it's not like they need much data. I have an IR ceiling fan, no issues there (even if the receiver is on a little wire that is supposed to stick to something but the sticktivity of the tape sucked), and a radio "smart" lighting system (just simple on / off switch on a plug socket). And some radio spots from IKEA, although I'm sure that can be hooked up to a "smart" system.

IKEA has consistent smart system that has the annoying feature that it works the wrong-way around for my use-case. The cheap IKEA switches can control IKEA peripherals only directly, you can't use them to control something outside of the IKEA ecosystem. As most of the things I want to control are either HomeKit native things or digital outputs on PLCs it does not work for me. So in the spirit of true overkill I have few switches that contain OrangePi Nano (I had somehow absurd quantity of these laying around as leftover from previous even more misguided project)

You should be able to integrate your IKEA and Homekit devices into the one if you use HomeAssistant.

The IKEA Tradfri system is all Zigbee based - I have a bunch of their light bulbs and strips, plus a few smart power plugs. I personally have them attached to my own Zigbee controller, but there's also a Home Assistant Tradfri integration if you want to keep using their Smart Hub controller.

There's also a Home Assistant homekit integration, so you can use HA to orchestrate events happening on the Tradfri side to trigger something in the Homekit side, or vice versa.

(I don't have the Tradfri smart hub or Homekit devices, so YMMV on specific possible options)

My beef is with the fact that the battery powered switch wants to be paired with the thing it directly controls and cannot be used alone with it just controlling something that is on the other side of the tradfri gateway. The five button round one apparently can be used for that, but the two position square one can't.

By the way the tradfri gateway is weird piece of hardware, the thing is mostly empty and only contains small board with apparently the same RFSoC as all the other tradfri peripherals connected somehow to ethernet PHY…

> The cheap IKEA switches can control IKEA peripherals only directly, you can't use them to control something outside of the IKEA ecosystem.

You can! Just pair them with a ZigBee hub directly.

Gree HVAC units have built-in wifi which supports fully local remote control and there are OSS packages (including home-assistant).

I did the same, i recommend getting the moes or similar IR blaster (tyua under the plastic). Treat yourself and get a combo temp/humidity sensor + IR.

For one of the rooms i opted for a IR/RF transmitter and the RF covers any RF enabled devices in the house (433mhz + 315mhz[i think but haven’t tested])

I also just got AC last year, and while it doesn't have as many fancy features I'm glad I got one that works with standard 24V HVAC wiring. I built my own thermostat out of an ESP8266, I²C temperature sensor from adafruit, and three TRIAC circuits to control the fan, heat, and ac wires. Connected to MQTT and I can send control commands to it from my Home Assistant instance!

If you have the code for this publicly (or would consider making it so) I would be quite interested in it.

There are a fair number of DIY thermostat projects online, but all that I have found were one-offs by their creators, or were for specific kinds of systems like boilers.

I've been batting around the idea of starting a general-purpose IoT thermostat that only uses cheap, widely-available components that anyone can easily duplicate with a BOM and 3D printer.

My first model is pretty janky and definitely built as a one-off, lots of hard-coded stuff in the arduino code I wrote for it that are specific to my setup. I've been thinking about making a new, more streamlined version that could be fully assembled by a fab and sent ready to flash and wire up into an HVAC system. And of course, I'll publicly release the KiCAD files and code for that when it's ready! :)

Ah, do you have some tips for someone who wants to do something similar?

I use AC units that come with IR remotes (Samsung maybe??) but the timers don't work for some reason. It would be great to hand roll some automation, but I never "hacked" IR remote/receiver systems.

Start Simple is my suggestion.

Home Assistant supports a huge range of integrations.

Personally I am using Broadlink RM4 Mini IR blasters. One in each room. They get added to Home Assistant as devices.

Then I use one of the climate add-ons that can send IR commands via the Broadlinks.

funny - I literally bought a broadlink ir blaster today and got it hooked up to HA about 15 minutes ago, looking to do this exact same thing.

Out of curiousity, did you have any resources you were following to set this up? I'm pretty new to HA - basic devices etc seem fine, but I'm not entirely sure where to go next!

Welcome to the club.

I'm using Broadlink RM4 Mini's I got off AliExpress. They've got a powerful enough IR signal that I've found I don't need them sitting way out in the open and obvious. One is tucked behind a TV and not quite in direct LoS, one is behind, but it reflects off the wall just fine, another behind a bedside table.

For the integration/Climate control thing I'm using SmartIR. Configuring it is a bit weird, you have to put it direct into the configuration.yaml file unlike other integrations.

    smartir:
      check_updates: true

    climate:
      - platform: smartir
        name: Bedroom AC
        unique_id: bedroom_ac
        device_code: 1293 
        # https://github.com/smartHomeHub/SmartIR/blob/master/docs/CLIMATE.md#available-codes-for-climate-devices
        controller_data: remote.mini4c_bedroom
        temperature_sensor: sensor.airquality_ikea_bedroom_temperature
        humidity_sensor: sensor.airquality_ikea_bedroom_humidity
        power_sensor: binary_sensor.contact_bed_ac

How did you pick cheap blasters compatible with HA?

I have a Broadcom one which works well but expensive.

Reddit and Google was how I chose which one to go with.

The Broadlinks RM4 minis were pretty cheap on AliExpress. I think I paid about $15 each? Might have to wait for specials to come up to get the lowest price.

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