The 50-70 FPS is the cap when the lens is open. It is supposed to be lowered to 2 FPS when the lens is closed, but I guess there is a bug here somewhere - which I'll fix eventually

The CPU usage when the lens is closed is 2-7 % on my device, which still is a bit too high, but I guess this is because of the 2 FPS. In fact, it could be lowered to 0 FPS, as there is nothing to be redrawn and rather implement a manual redraw function if necessary. I'll see if this helps. The result page CPU usage is probably also because of unecessary redraws causing CPU wake-ups.

I'll see if we can add an option to manually tell mBarcode to scan, but I don't have the time to do it right away, so it might take some time if I get to it.