Okay, so I have been measuring my energy-usage through a custom solution since 2015. I did not have any smart-home-system by then, but I figured out a solution using an Arduino Mega to send my usage to my own private website where it all gets stored and visualised. When I first got Domoticz, I could easily integrate that into my solution by sending the P1-telegram to Domoticz and I was done.
In the past couple of months, I have installed Home Assistant (the OS-version on a RPi4), and connected the basics (a couple of lights and my thermostat via the OTGW that I already had). Now I was wondering if it is possible to send the P1-telegram also to Home Assistant in the same way. Since the Arduino-script is obviously something I can alter any way I like, there are not much limitations there. I would just like to keep my solution in place, because I already have almost a decade worth of data from this, so switching solutions and abandoning thatway of storing data would be a bit of a shame for me.
Under Domoticz I just sent the values over ethernet and a Python-script called the correct devices within Domoticz to store the values there.