Hi,
I have a digital energymeter with day and night counter.
I can make a trend with the day and one with the night counter.
I want to show the sum.
I can do this with a rule the write to a new item.
Is the a possibility to do this without this. The problem is that it will calculate from the moment that i create is, and not with the existing data.
Also, then OpenHab must store the calculation in the database, what is not necessaire, because the separate values are already stored.
Thanks,
Marc