Ahhh.

Try turning the knob one click at a time, and waiting for the display to change. There's possibly 2 things going on here:

1) The logic for the knob encoder can mistreat fast turns in one direction to mean a slow turn in the other direction. I have no idea why this is - I haven't ever looked at/touched this code.

2) The button LEDs implementation in the PIC doesn't (unfortunately) include a way to decrease the brightness, only to switch the LEDS on, off or increase the brightness in 5% steps. So when you try to decrease the brightness, what actually happens is the LEDs get turned off, and then brightened to the new (less bright) level. I've already mentioned that the timing of the PIC is slow, so this chain of commands takes time to execute. Be patient with it, and it should work.

There is another workaround for this. The top button should reset the button LEDs to 'Off'. Then use the knob to increase the level. (ie, doing the same thing manually).

The whole button LED code is due a re-work, as soon as I can find time to do it.