This is some incredible work! I found a Daikin open source WiFi module replacement, and was wondering if anyone was working on something similar but for GREE instead, and here you are!
I’m not sure if this is within the scope of these project, but I think so…
It looks like this can replace the official GREE module, with some benefits, but I think could be an added benefit, which could be extremely significant.
Most (all?) GREE boards, for high wall units, concealed duct, slim duct, floor/ceiling, etc have at least ONE plug for control. COM-MANUAL and this is how you connect the wired wall-mount controller. Many, certainly newer, have the WIFI plug as well, where you can plug in the GREE module (or, presumably, yours!)… But a lot don’t have the WIFI plug. Especially the off-brand versions of GREE which are often one-generation-old models.
The benefit I see is that if this could be made to work with the COM-MANUAL plug, instead of (or in addition to) the WIFI plug, it would be able to add WiFi to ALL Gree air handlers since nearly every single one has a COM-MANUAL port, even if they don’t have a WIFI port.
The connection and protocol for the COM-MANUAL port seem to be the same as for the WIFI port.
GREE actually has done something similar themselves with the XE-72 controller. It is a wired wall mount controller, but it builds the WiFi module into the wired controller. This allows added WiFi to units other than the typical High Wall models. As well as older models.
The limitations, of course, are that GREE’s WiFi provisioning method are a REAL pain in the rear, using the GREE+ (or EWPE) app. Also, of course, “calling home” and needing to maintain an account with the GREE+ app.
If the custom module has a built-in web-page, you could set up the module for WiFi access by simply typing in the SSID and password, no need to go through GREE’s hoops.
The COM-MANUAL port can handle all the same commands as the WIFI port, and as far as I can tell, they are the same commands.
The COM-MANUAL port can also provide the air handler with the ambient temperature, overriding the ambient temperature detected by the air handler itself. The built-in temperature sensor can be unreliable, especially in HEAT mode.
The Daikin open-source module dealt with this by allowing a Bluetooth temperature sensor to connect to the WiFi module and it would use that sensor’s measurements and send it to the air handler. (Daikin’s built-in ambient temperature sensors are just as unreliable as GREE’s due to being IN the unit, often high on the wall, far away from where people actually are.)
A module that plugged into the COM-MANUAL port rather than WIFI could completely bypass GREE’s app, would work with all AC’s all the way back to around 2013 when GREE made the COM-MANUAL port standard for all unit types.
The biggest hurdle I see is I don’t know how a module would initiate communication. Although this may be the same as the WIFI port you’ve already figured out, because they both use the exact same 4-pin interface. The other is while the AC control related commands are almost certainly the exact same as the WIFI module, I don’t know how to figure out the extra commands, like sending an override ambient temperature measurement like the official GREE XE-72 controller does. I’m sure it would be the same style command as the AC control commands, but I don’t know what it… is.
Just some thoughts on a way to make this even more beneficial to even more people. There are many many units out there without the WIFI plug, but they all have the COM-MANUAL plug, and this could add WiFi to previously WiFi-incapable (or capable only with the XE-72 controller) units.
Thanks for all your efforts!
