Using and Tweaking buttons for rudders?

[Inrideo]

I just build a simple PVC pipe collective, which works great. So I wanted to throw together a simple rudder system until my neodymium magnets arrive.

 

I put two arcade buttons on an angled footrest, and they work well enough, but are much like the Z and X keys when it comes to tapping them. The results are not consistent.

Is there a tweak that would make the rudder amount increase by a fixed percentage per tap?

[Inrideo]

Rather than hoping for a tweak in the game input that I don't know about, I think I can alter the code on the Arduino to only register single tap-and-release sequences.