Heat pump controller on Arduino via USB
Posted: Sunday 18 December 2022 13:46
Hi everybody!
I am trying to get a ground source heat pump integrated into my system. I got this brand new prototype heat pump for free, but with no functioning controller board. Small model, just 8 kW max output. I intend to reuse the pre-installed pressure and temperature sensors and relays to get it up and running.
There is an open-source heat pump controller here: https://github.com/openhp
I flashed the code to an Arduino Uno and will interface it through USB. From Visual Studio I was able to read the serial interface, that is, printout of status and sensors readings. So it seems to work. I won't use the described hardware and display from github, just the serial interface.
From Domoticz I need, as a minimum, to set a target temperature and a target differential temperature, and read back all sensors.
I find that when I connect the Arduino to my RaspberryPi 3B+ (Domoticz), the Arduino (or AliExpress lookalike) appears on ttyUSB0 ("lsusb" lists it as Bus 001 Device 008). So we are connected. And the rpi and heat pump will be located near each other.
From there, I am quite helpless. I believe I may need:
- a serial/USB gateway?
- a Python script (or dzvents, LUA) (example python code on the github link)
- virtual sensors/switches
For information, I do have a 350 meter hole in the ground and brine loop ready. I also have an old, but functioning air to water heat pump which can run in parallel in my heating system. In a year or two, I will replace the old heat pump with a bigger ground source heat pump, but keep the small one in parallel.
Norway is freezing cold right now, and I would appreciate your help to get this controller up and running.
I am trying to get a ground source heat pump integrated into my system. I got this brand new prototype heat pump for free, but with no functioning controller board. Small model, just 8 kW max output. I intend to reuse the pre-installed pressure and temperature sensors and relays to get it up and running.
There is an open-source heat pump controller here: https://github.com/openhp
I flashed the code to an Arduino Uno and will interface it through USB. From Visual Studio I was able to read the serial interface, that is, printout of status and sensors readings. So it seems to work. I won't use the described hardware and display from github, just the serial interface.
From Domoticz I need, as a minimum, to set a target temperature and a target differential temperature, and read back all sensors.
I find that when I connect the Arduino to my RaspberryPi 3B+ (Domoticz), the Arduino (or AliExpress lookalike) appears on ttyUSB0 ("lsusb" lists it as Bus 001 Device 008). So we are connected. And the rpi and heat pump will be located near each other.
From there, I am quite helpless. I believe I may need:
- a serial/USB gateway?
- a Python script (or dzvents, LUA) (example python code on the github link)
- virtual sensors/switches
For information, I do have a 350 meter hole in the ground and brine loop ready. I also have an old, but functioning air to water heat pump which can run in parallel in my heating system. In a year or two, I will replace the old heat pump with a bigger ground source heat pump, but keep the small one in parallel.
Norway is freezing cold right now, and I would appreciate your help to get this controller up and running.