How to Control Your Air Conditioner with Raspberry Pi Board and ANAVI Infrared pHAT

Leon ANAVI may be a full-time software engineer, but in his spare time he has started to develop open source hardware project with the help of others and by himself. Last year, I got hold of his RabbitMax Flex HAT for Raspberry Pi, and tested it with the provided LCD display, one temperature sensor, and a Raspberry Pi 2 board. The board also featured IR receiver & transmitter, and I tried to use it with my aircon remote control, but at the time I did not find a way to do it easily, and control my TV with LIRC instead. Leon has now made a simpler, smaller, and cheaper add-on board for Raspberry Pi Zero, and other Raspberry Pi boards with a 40-pin header, with 3x I2C headers, two IR transmitters, and one IR receiver. He sent me a sample of “ANAVI Infrared pHAT”, and after quickly describing the board, I’ll show how to I could control my air conditioner with a Raspberry Pi 2 board and his Infrared pHAT.

ANAVI Infrared pHAT

The top of the has the 3x I2C header for 3.3V sensors, a UART header to access to serial console, two x 5mm IR transmitters (IR LEDs), and one IR receiver (IR photo sensor). It also has an EEPROM to store the HAT ID.

The other side comes with the 40-pin female header to connect to your Raspberry Pi board.

The board was designed with KiCAD, and the hardware design files are released under a “Creative Commons Attribution-Share Alike 3.0 United States” License on github.

ANAVI Infrared pHAT Connection to Raspberry Pi Board

There’s only one step: insert the board on the 40-pin connector of your RPi board. You can only make one mistake, inserting it the wrong way. It has to be connected in away that it covers part of the board.

I’ve connect it with a Raspberry Pi 2 board with a battery kit, but it fits even better on the Raspberry Pi Zero, or newly released Raspberry Pi Zero W.

Setting up Raspberry Pi, and Controlling the Air Conditioner with LIRC

It’s time to start software setup in order to control the Haier air conditioner pictured below.

You’ll need to install Raspbian, and some packages including LIRC, but I’ve already explained how to do that in RabbitMax Flex Getting Started Guide, so I’m not going to repeat those steps here, especially you can find them in ANAVI Infrared pHAT user’s manual too, and I’ll assume you have already setup your board.

The reason why I could record IR commands from my TV remote control, and not my aircon remote control last time around, is because aircon remotes send not only one byte but also status info each time. The trick is to use mode2’s “alternative display mode” to capture pulse/space data as raw config files.

Let’s do that:

Now I faced the IR receiver and pressed the power key on the remote control:

Wow, that’s a whole bunch of numbers, but that’s exactly what we need as those are the duration of the high and low levels of the IR signal. I have repeated the same command, but capturing 4 keys: off, on, up to 29C, and down to 28C.

Then we need to edit our lircd-haier-ac.conf file manually:

Note that you need to delete the first “big number” from each captured command. For example, I had to delete “4989552” from the first capture of the power key. If you want full control, you’ll need to record all keys. You may want to read lircd.conf manual to understand parameters like aep or aeps. I used the default values, but in case it does not work for you, or works unreliably, you may have to adjust them, possibly from data obtained using an oscilloscope. I did not have such problem, and copied the file to /etc/lirc/lircd.conf:

In theory, you can restart lircd from the command line:

but in my case, I always had troubles when running irsend command:

So I had to reboot the board with sudo reboot to enable changes. Later I used the reload command (to take into account the update config) after restart, and I could avoid a reboot:

Once it’s all working, we can list the keys we’ve just defined in lircd.cong:

To turn on the aircon:

Then I was not sure what action would happen when I recorded the up key once setting the temperature. So I first set the temperature to 23C to check whether it would increment the temperature to 24C, or set it to 29C:

And the later happened, which means you need to record all temperatures you want to set, and there’s no such thing as UP and DOWN keys.

You’ll already guessed how to turning off the aircon:

Then I realized that since “29C” and “28C” commands send the temperature, it might also send the power status, and indeed I can turn on the aircon @ 28C directly with with 28C command. So instead of recording keys for your aircon, you are actually recording “scenes” which you could name “night”, “25Cfanlowswingup”, “off”, and so on. I added 25Cfanlowswingup with temperature set to 25C, fan speed set to low, and swing set to up, added it to lircd.conf, and a single command would turn on the aircon and set all those values:

Pretty neat.

While the instructions above will work with any board with IR receiver (for first time setup) and IR transmitter, you may be interested in getting ANAVI Infrared pHAT on Indiegogo for $9 plus shipping ($5 to  $7). There are also other rewards including the pHAT, I2C sensors, and debug tools. The campaign has already surpassed its funding target ($500), and delivery is planned for September 2017.

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.

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