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How to receive an IR signal of air conditioner signal for reverve engineering?

Nmaster88

New Member
I have white brand of air conditioner, so i have no idea what IR protocol it uses, is there any solution that uses a IR receiver in a way that i can reverse engineer?

It can be something that uses a Arduino Uno (i have one).

After i find a solution for IR signal receiver that works, in future, i would like to go to a phase 2, where i would send the IR signal to the air conditioneer, with a device, that can be controlled remotly.

But for now, how can i get the signal from the controller of the air conditioneer?
 

dougy83

Well-Known Member
You can connect a phototransistor across the microphone input of your PC and record the audio using e.g. Audacity. The data (with carrier removed) will be obvious, and you can decode manually or via software.

If you want to use existing software, I believe LIRC can receive and record the decoded data so that you can play it back. Ref http://www.lirc.org/ir-audio.html (that's connecting to the audio input port, again, but there are other interfaces you can use with LIRC)
 

Pommie

Well-Known Member
Most Helpful Member
Install a universal remote on you phone/tablet. Then try the different models to find one that works. Then google the protocol.

Mike.
 

Nmaster88

New Member
I installed Mi Remote Controller and at least 2 work with my air conditioneer: Benwin A/C and Midea A/C.

Let´s see if with this information i can do something.
 

audioguru

Well-Known Member
Most Helpful Member
Why does an air conditioner need a remote control? My central air conditioning is set to be on during Summer and be off during Winter.
Sometimes in Spring and Fall I simply walk past the thermostat to turn it on or off. It automatically sets a day and night temperature.
 

ronsimpson

Well-Known Member
Most Helpful Member
simply walk past the thermostat
There is a channel up and channel down button. Volume, mute, on, off, temperature up, temperature down buttons. Buttons for recline, vibrate, feet up/down. On the phone there is a button to order pizza right next to the "elector-tech-online" button.
There is one that that needs a button. So for now I have to yell; "bring me a drink" which if followed by "get it your self, lazy old may".
 

Nigel Goodwin

Super Moderator
Most Helpful Member
can i get somewhere the protocol for the Benwin A/C and Midea A/C or do i really need to use a solution like @
dougy83
is suggesting?
Depends if you can find someone who has already done it or not?.

However, I would suggest NOT using a photodiode to read it, use an IR sensor IC instead, this strips off the carrier frequency, and provides the actual data that you need. The carrier frequency itself isn't very important, around 38KHz seems pretty universal and works with everything (except some very old B&O TV's, which used 100KHz for some bizarre reason).

I've reverse engineered various remotes over the years, all using IR receiver IC's to demodulate the signal - originally I used a 386 DOS Laptop parallel port, and a program I wrote in Turbo Pascal. Since then I've used the PC audio input and Audacity (attenuate the signal from the sensor first), and more recently I've also used a PicKit3, which has a simple logic analyser built-in.

I've now got a couple of the cheap Chinese logic analysers, so I'd use those if I was doing one now - mainly due to memory constraints on the PicKit3, which only barely has enough space to do it.

As examples, here are a couple of the PicKit3 screen shots - these were 'setup' and 'enter' respectively.

setup.GIF


enter.GIF

In this particular project, which I did for a company, I was only interested in transmitting a duplicate (without carrier), to create a minimal wired set of buttons to replace the IR remote.

Interestingly, as the IR sensors work by effectively pulling down an O/C output pin, I was able to simply connect an O/C output in parallel with the sensor, so it worked from either the new manual buttons, or the old IR control as well. So it made it easy for any changes to be made, that weren't possible from the new minimal manual buttons. Basically they wanted an 'idiot proof' wired control system, so the people working it couldn't mess with the settings, and couldn't lose the remote.
 

ClydeCrashKop

Well-Known Member
Most Helpful Member

dr pepper

Well-Known Member
Most Helpful Member
There is a sketch on arduino playground for a IR scanner, it will tell you what type of protocol an IR remote uses, and I seem to remember it'll tell you the codes too, so long as your aircon uses a protocol it recognizes.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
There is a sketch on arduino playground for a IR scanner, it will tell you what type of protocol an IR remote uses, and I seem to remember it'll tell you the codes too, so long as your aircon uses a protocol it recognizes.
I presume you didn't read the post immediately before yours?, post #10 :D
 

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