How to make "smarter" a wired aircon remote

hi all,

I am trying to setup an openHAB in a rental place, and I am really trying to “optimise” the expenses…

I have two ducted Panasonic air conditioning systems (one for the ground floor and one for the upper floor). both of them have wired wall remotes which I would love to “automate and integrate with openHAB”.

My requirements are:

  • regulate the internal temperature remotely (via openHAB) (different rules for ground and uper floor)
  • set rules to activate/deactivate the aircon accordingly to external temperature (different rules for ground and upper floor)
  • automate the on/off accordingly to my GPS position (on my mobile) (different rules for ground and upper floor)

anyone has any idea where should I start? which hardware do I need? maybe the best idea is to get two Nest system, but I would prefer “saving some $” on top of the personal satisfaction of DIY! :slight_smile:

Thank you all


What have you researched so far? Does it have a BUS? uart? If you’re not familiar with reverse engineering protocols, you can do this:

How many wires do you see if you pull the panel off? You should see at least 4 wires: common, fan, power, cool… if there’s an extra wire it’s for heat. Get a ~$5 esp8266, 3 relays, a temp sensor, a buck converter, and a few strips of wire. You should be able to “smartify” your cooling system for less than $20 assuming you know electronics.

thank you Lucky… this is what I conceptually thought I should have been done…

Please be patient with my “low electronics knowledge”… I have started putting on paper the suggested components… now, next step, how do I connect them? :slight_smile:

Thank you :blush:

With wires…no seriously you basically asking for someone to design the system for you. Diy means you need to do it yourself and if of course can ask specific questions. But don’t expect some else to build your diy system. You should really question if this is something you should do and maybe just first start experimenting with electronics, how to program, and learn. Regarding you home automation. If your knowledge is limited just buy hardware that works out of the box with your hardware and check if it works out of the box with openHAB so you can connect the devices. This will be the least frustrating path to take.

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I understand your point, but we should all start form somewhere, right? I have no problem in the SW programming side of the solution, but the “hw” is not my “bread”… but keen to learn…

I will try a “schema” and re-post it, it that makes more sense here

@ip_finar pls read more. I’m gonna say this politely but @hilbrand is right. I suggest you just purchase a ct100, a zwave thermostat. It appears you have little knowledge of electronics. I could tell by the colors you chose on your diagram. Most AC systems are 24V. I just want your system to be safe and reliable.

If you want to proceed, there are available DIY systems available online for you to read. Start with how your AC system is wired. Once you identify (take photos) the wiring, I can better assist you.

Yes, please note and respect the forum policy. It is NOT on home automation and electronics in general.

I’m sure people on the forum can and are willing to help with integrating into OH once you figured out the HW part, but that you have to come up with yourself.
To speak frankly, it really takes a LOT of engineering in HW and SW to get that stuff right (and I did with my aircon so I know what I’m talking about). Reverse engineering proprietary protocols in terms of HW and SW is a real tough one.
I know you won’t want to hear that, but as you considered your own electronics knowledge to be “low”, the best advice is probably to refrain from that idea.

:slight_smile: But it’s so much fun with a Bus Pirate or attify . I use attify most of the time

Ooooooookay … we all have our fetishes :wink: and I didn’t want to stop you from helping … but the average user keeps greatly underestimating the effort and required know-how hence my advice.

:slight_smile: Yeah it was an in-the-moment reply

It’s probably worth revealing your AC model(s), which will help identify what features they might have that you can exploit.

@luckymallari, @mstormi, @hilbrand, thank you so much for your suggestions and I do understand that this might not be the right forum for this… I was just trying to get the “shopping list” that would work with openHAB, then go to a “electronics forum”, seek for help, study e do a bit of trial and error… then finally come back here and finalize my project in terms of openHAB configuration…

I have done a bit of further investigation (I am currently working away from home Monday-Friday) and only weekends I can dedicate to this project :slight_smile:

Compare to what suggested by @luckymallari, my system has three wires:

  • GND : Ground
  • 12V: Power
  • SIG: I assume “signal”

please see pictures below:

I have done some more researched, and I think I have founded a similar “project” here:

now, without upsetting anybody, where do you think I could start? (I am really willing to learn :))

Thank you all

The instructable is a very good find. But this is likely to turn out as a ‘very interesting’ hobby project, not a quick setup :smiley:

I guess your next step would be to find out how similar (hopefully identical) the serial protocol used by your machines is. Ideally a friend with a storage oscilloscope (simple ones take the form of a laptop + USB stick these days) can see if your communications match the instructables.

On that link it seems that a checksum of the payload is required as sort of validation for the unit to verify data. This is usually the trickiest part of protocol hacking. Some manufacturers have their own algorithms so others won’t be able to just decode/encode their data. This will be for you to figure out if your at least able to get into the protocol. I would attempt a replay attack first and if that works, then that’s all you need to do.

My next step for you is to identify the main AC unit. What you have shown so far is just the “remote.”