I spent quite some time to get my pool heatpump integrated with tuya local and local tuya but wasn’t really happy with the outcome.
Inspired by user enboer sharing a direct interface with domoticz, I set about doing something similar with esphome.
This is the outcome in the dashboard:
Errors can also be shown:
It all starts on the main control board which is easily accessible:
B and A are the RS 485 headers and the connector even provides 12V power for the ESP.
After a bit of prototyping…
I came up with this:
At the top is the connector, stays within the enclosure. Middle left is a small stepdown converter to get from 12V to 5V for the ESP. On the right is a MAX485 based RS485 interface. At the bottom you see a custom board I use for ESPHome projects someone shared on PCBWay. I flash the 12E/12F module and then solder it to the board, OTA from there.
Next was an enclosure:
The electronics are placed in there, the boards separated by two of the H-shaped spacers. Once the box is screwed closed, two holders are attached wich allow clipping it to the heated water out pipe at the back of the machine. The cable comes out at the bottom, so humidity should not be too much of an issue. I’ll add a TPU based seal later.
I plan to add the files on github later. So far I’m really happy with the results and best of all, I can elminiate the tuya cloud. Also directly communicating with modbus unlocked a “super silent” mode which is not available via the hardware user interface or the tuya based app.
One note on compatibility. I have an IPS pro by Poolsystems which seems to be identical or very similar to the Inver X from Fairland directly. These heatpumps seem to be sold under many different brands. At least for my model, you can add the feature to control it via app. It looks like all they do is ship the unit with a different controller which is in box separate from the main controller. At least this is where the WIFI module is located as inside the metal enclosure of the heatpump, there would be very little reception. It looks like the main control board is the same with or without wifi support. My guess is, one could buy the cheaper option without app and make it smart with the solution described above.
I already have ideas to improve my solution. The M5 stack tough seems to fit in the space of the current UI box. Moving the original box to the inside or disconnecting it entirely I could use the M5stack to control the pump manually adding things like presets or other advanced things.