i’m so sorry but i really don’t understand how to start.
I bought an HEM-G2 (power meter Aeon); installed and now works correctly (also negative value when Solar Panel have a positive production).
Now i’d like to make a graph about instant power.
But really don’t understand how to put this data on a DB and then create a graph.
Can u suggest me something?
Tks in advance
First start to persist your values. Qucik and dirty use rrdj
To expand a bit on @Dibbler42’s answer. See the Persistence wiki page for details on how to set up saving the values to a database for charting. rrd4j is a good choice for something like this where all you want is a chart of relatively recent data. Pay attention to the bolded text if you do use rrd4j; you must save the data using at least an every minute strategy or else it won’t be able to produce charts.
However, if you want to keep exact values forever, db4o or one of the external DB servers like MySQL are a better choice.
Then look at the “Chart” element on the sitemap wiki for how to graph the values stored in the DB.