I would like to control the aircons in my house with the phone. Is there a device to do this with? I thought about using a cheap Sonoff switch but I am not sure if it is good for the aircon to just cut the power. With the Sonoff I would also not be able to adjust the temperature and fan speed.

If you're up for changing your AC's plug, then google:

Xiaomi Air Conditioning Companion with Temperature Humidity Sensor

Edited November 23, 20196 yr by phil.g00

1 hour ago, phil.g00 said:

Xiaomi Air Conditioning Companion with Temperature Humidity Sensor

thanks for the link. This is basically an on off switch. Do you think it is ok to switch the aircon on and off like this. When I switch the aircon off with the remote control it does not switch off immediately. It slowly reduces the compressor speed and then the blower fan in the indoor unit runs at a very low speed for about 5 minutes to dry out the evaporator. With this switch I can also not control the temperature and fan settings.

Yes, it will be a switch, just controllable with temperature/humidity and times.

I would imagine your AC goes through this routine because its designer thought that this was the best for it.

So I think what you are probably looking for is more along these lines::

 

9 minutes ago, phil.g00 said:

So I think what you are probably looking for is more along these lines

perfect! Thanks.

There's one that shows up in my facebook ads, called the Sensibo Sky (Takealot sells it too). It simulates the IR signal of the AC's remote. No idea if it is any good.

What I know about AC remotes... they are different to your normal television remote. They hold state.

Remotes for AV equipment are stateless. They simply send a signal that identifies the button (usually a modulated 40Khz signal).

But an AC remote keeps the entire state of the unit (what it should be doing, what temperature to hold, and so forth, even stop and start times), and when you hit a button this entire data stream is sent to the AC. The upside is that if you know the protocol, it makes it really easy to control the AC.

I googled around a bit and found this. Pretty much what I would expect, a 38khz carrier signal with a binary stream modulated on top of it that simply carries the packed values of the various fields. This guy used a PIC microcontroller, but you could probably figure it out using a storage scope (if you have one) or even an Arduino. The magic is all done by a discrete TSOP chip.

Modulating a 38khz signal is easy enough. You could probably do it directly with the arduino (Usually the trick is to get close by using the right divider values in the timer registers) but it's easy enough to do it with an NE555 where you just stick the signal onto pin 4 (reset, active low).

I use a Broadlink RM mini 3, works brilliantly. very easy to setup

also works with IFTTT

Edited November 25, 20196 yr by RichieRich

7 hours ago, RichieRich said:

I use a Broadlink RM mini 3, works brilliantly

What kind of range do they have? Do I need one for every room?

5 hours ago, Fuenkli said:

What kind of range do they have? Do I need one for every room?

They work with IR so one per room.