Improve button response: Smush the carbon rings

The title sums it up. I just found that I could get much more sensitive button response (and far fewer undetected presses) if I first 'smushed' the carbon rings on the underside of the keypads against the circular flower-like traces that they sit above. I'm not sure exactly why it works, but it's helped quite dramatically.

I removed the outer-most top plate so I could grip the buttons properly, then simultaneously pressed and twisted each one left and right, rubbing the carbon ring against the pcb.

If you're getting a lot of missed button presses with your arduinome give it a try.