Hi,
This isn’t exactly 100% OpenHAB related, but I’m hoping someone will know exactly what I’m talking about and point me in the right direction.
I have a Thermia Calibra Eco8 heat pump which has inputs for either a Modbus or PT1000 temperature/thermostat.
See top left of pic for PT1000 input, and middle right for the Modbus input (MBa)
I want to use an ESP32 to send data to either of these connections so that I can use temperature sensor data from OpenHAB to set the measured room temperature on the Thermia heat pump.
A PT1000 sensor appears to use variable resistance to set the temperature.
Maybe I’m missing an important search term, but I can’t see any example of an ESP32 controlling variable resistance. Any one know how to do this?
The Modbus option is probably the preferred option as it is digital, so possibly easier to set values correctly. After reading a few articles, I bought one of these:
I thought I would just YOLO it and figure it out as I go, but quickly realised that I don’t know what kind of signal I am supposed to generating, or how do do anything else for that matter. Most of what I can find online is about reading modbus values, not generating them. There is also no useful information that I can find about the Thermia heat pump inputs. What registers are involved etc. The only Modbus documentation doesn’t seem to mention anything about room temperature.
Anyone know anything about any of this?
Or is there another approach I haven’t thought of to achieve my goal?