Reverse engineered IR protocol for HomeFit Living / Alaska SAC9010QC / SAC12010QC remote control based on an NEC 756504012 IC. It is apparently also known as the "Gree Y502 / Y512" remote and the silkscreen on the PCB states "Gree 5I2".
If you want to go straight to the juicy parts, go checkout protocol.md.
The documentation directory contains the SAC9010QC / SAC12010QC manual and other resources used. The pics directory contains some photos of the remote control, it's PCB and my test setup. dumps contains a few PulseView dumps of the IR signal as captured by my DSLogic Plus.
Finally, src contains a simple webserver that can be used to control the AC unit by using a REST protocol. It uses the WiFiManager for initial WiFi setup (connect to it's accesspoint, enter your WiFi SSID and password) and after that you can go to it's IP and do a GET on /state to get the current state (as managed by the ESP, not the actual state of the AC unit, since that cannot be read). The response will look like:
{
"power": false,
"temperature": 20,
"fanspeed": 0,
"mode": "COOL",
"swing": false,
"sleep": false,
"humid": false,
"light": false,
"ionizer": false,
"save": false,
"timer": 0
}The same JSON can be used to send a new state to the AC unit. Use the same /state endpoint and use the PUT method. The modes are: AUTO, COOL, DEHUMIDIFY, FAN and HEAT and are case-insensitive. Fanspeed 0 is Auto and can be 0 to 3. Temperature can range from 16 to 30. The timer is specified in half-hour increments and can range from 0 to 48 (24 hours). So if you want to set a timer for 13.5 hours use the value 27 (13.5hr / 0.5hr increments = 27). The air1 and air2 values (see protocol, bits 24 and 25) are currently not exposed over REST. The webserver uses IRremoteESP8266 for sending the IR commands (using the Teco protocol).
This is the actual remote:
