There are models of Gree AC that can be controller by XK19 Wired Controller or simmilar. But there is not option to controll them wirelessly for home automation (except IR blasters). The purpose of this repo is to describe protocol details between indoor unit and wired remote.
The unit is connected with the remote using 4 wires: GND, 12V, A, B.
A and B is a RS-485 communication bus.
Serial communication settings used on the bus are 1200 baud, 8N1.
The protocol can be described as follows:
<Header> <Src> <Dst> 11 <Body len> <Body>
| Byte | Message part |
|---|---|
| 0-1 | Header |
| 2 | Src |
| 3 | Dst |
| 4 | 11 |
| 5 | Body len |
| 6-* | Body |
The last byte of the Body is CheckSum8 Xor of the whole message.
The Header of any message is always 7E 7E.
During line sniffing there were met two Src: 00 and FF; and three Dst: 00, FF and 40.
The byte 11 is always on it's place right between the Dst and Body len.
| Src | Dst | Body len |
|---|---|---|
00 |
FF |
0E |
FF |
00 |
15 |
FF |
40 |
16 |
| Header | Src | Dst | 11 |
Body len | Body |
|---|---|---|---|---|---|
7E 7E |
00 |
FF |
11 |
0E |
00 00 02 01 89 8A BE 47 00 80 00 00 00 99 |
7E 7E |
FF |
00 |
11 |
15 |
0C 30 83 01 14 7E 22 10 E0 E0 08 00 02 00 00 00 00 00 00 00 17 |
7E 7E |
FF |
40 |
11 |
16 |
0C 30 83 79 6C 00 00 00 00 04 00 08 00 00 00 00 00 00 00 00 19 07 |
According to theese samples it looks like that FF is the indoor unit, 00 is the wired remote (XK19 is my case)
and the 40 is unknown (maybe centralized remote).