but I can’t find a good guide and can’t seem to be able to wrap my head around how it is supposed to work… sometimes I think I’m supposed to connect BOTH devices? Too many wiring/configuration options for me to work through not really knowing how it should work.
I’d prefer to connect it to a ESP32 tasmota but can connect it to a Raspberry Pi or even an OpenHAB instance if required.
Or, if you want to avoid the hassle with hard- and software, you could use a Modbus RTU to Modbus TCP gateway, they are available cheap on e.g. Ali Express, some even have Wireless LAN or MQTT support
Using the ModBus-Binding you can connect through the network, which is pretty much straight forward and you do not have to find a way to wire it up to OH.
Just found this video , seems this is proving all you need. there seems to be a manual attached to the answer given there, but i did not check it.
Personally I prefer a litte less “bare metal”, I run a Protoss PW21H and a USR DR302.
Never went down the ModBus<->mqtt path as the binding is working for me and it just adds another layer of complexity in the initial setup. Would go for modBus binding and, when everything works, maybe try mqtt so you have one binding less (if it is only for the sensor you have).
for anyone who finds this thread, the video is slightly helpful. I struggled for a bit, figuring I was doing something dumb, and then just changing relevant-looking settings. This setting needs to be ‘open’ not ‘closed’ as described in the video…