#Automating apartment air-con wall controller.

1 messages · Page 1 of 1 (latest)

long shadow
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See the image attached of the back of the air-con controller in question. I'm looking to simulate short button presses to automate power on/off and temperature control on my apartment air-conditioning.

Doing some research I'm seeing that Optocouplers are a good option for this, but I'm not sure specifically what I'd need.
I found what I believe is a suitable Optocoupler board and an ESP32 board to go along with it, but I'm not sure on compatibility or where to look next at getting this all put together.
Hoping someone can guide me a little

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rancid fulcrum
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  1. How many button presses in a day are we talking?
  2. Are you already in the ESP32 ecosystem? I ask because I'm not and the reason is it sounded like it was going to take a bit more time to get up to speed than I had available.
  3. I'm sorry to ask the obvious, but you've certainly determined a Z-wave thermostat (or similar) can't meet your needs?

A long time ago I tried to use optocouplers on a project and found they don't work "just like relays" as I hoped they would. I can't remember the details, but in my case I needed to add additional components that made me just switch to mechanical/reed relays. Hence my question about how many button presses.

You may also be able to use a little digital IO module, ideally something that could be powered from the power on that AC controller unit. You could possibly connect IO pins from the module directly to the switches to drive the pins on the processor. in other words, instead of simulating switch presses by connecting those pads on the PCB you would actually put the 3v or 5v signal on the Input pins on the controller processor. Assuming you trace/tone those switch pads back to IO pins on the processor. And I mention powering the module from the AC controller to avoid any ground-loop, mains adapter induced magic smoke.

Note: I barely know what I'm talking about, in fact I may be wrong on some points but I dont' think so. LOL

zinc drift
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Yeah the 817 should be fine for that use
If you can find 5v or 3.3v on the board, I would use that to power your esp
I would not use the olimex PoE ISO board for this, unless you are specifically intending to use PoE - I would use something small and cheap like an esp32 c3 supermini

long shadow
# rancid fulcrum 1. How many button presses in a day are we talking? 2. Are you already in the ES...
  1. Anywhere from 1-12.
  2. I'm not.
  3. Yep, very proprietary system shared across other apartments, no chance of changing the wall controller without changing the whole air-con control board.

A long time ago I tried to use optocouplers on a project and found they don't work "just like relays" as I hoped they would.
That's interesting, if there is a better product for the job I'd rather use that then.

instead of simulating switch presses by connecting those pads on the PCB you would actually put the 3v or 5v signal on the Input pins on the controller processor.
I'd rather not modify the actual Air-Con control board if avoidable, I'm sure it might be neater but the risk of breaking it seems quite high, and this mod is something I'll need to undo if I ever move out.

rancid fulcrum
long shadow
# zinc drift Yeah the 817 should be fine for that use If you can find 5v or 3.3v on the board...

Yeah the 817 should be fine for that use
Thanks for confirming, do you also know how it interfaces with the ESP32?
If you can find 5v or 3.3v on the board, I would use that to power your esp
That's a good idea, I would do that if I knew more about the air-con control board, but it's not exactly accessible enough to be testing voltages and it's super proprietary that breaking it might cost a fortune.
I would not use the olimex PoE ISO board for this, unless you are specifically intending to use PoE
Yeah I was looking for something PoE based since I've got a lot of spare cabling and don't want to worry about cheap power supplies making a mess or instead overloading the air-con control board.

long shadow