External consumption data gathering (Shelly, etc)

[bigjools]

I don't know if there's any appetite for this but I don't have a smart meter, so I have a Shelly 3EM reporting consumption data. I upload that along with the SunGather data to pvoutput using a custom Python script that I wrote.

I can add this script into SunGather if there's enough interest? It should just be a simple case of an extra poll to whatever device provides the data, and insert it into the registers that would normally show consumption from the smart meter.