[x] VA Meter should store the current windows at each operation, and recover to the state after power cycle
[x] The scaling in plot mode should be improved, or at least be able to adjust by human or have different modes can select. When the voltage and current difference is small, it is very hard to see the trends.
[x] VA Meter should allow easier operation for the base (not like current deeply hidden in the settings menu), and the relay in base may need to be connected on boot. (or have some memory )
[ ] More mesurement can be include in the plot mode, like amplitude, max, min, average