Arduino drive 1

Here, the same setup as the Spiral, with a pendulum starting at zero
angle and getting driven at the resonant frequency.  Nonlinearities are
such that as the amplitude goes up to a certain level it rolls over and
goes down, then back up, etc.
First chaos demo on Arduino

Here the basic code is the same as the first driven one, but the
resonant frequency is lower, drive is harder, and there is more
damping, making a much more chaotic system.  See corresponding
processing code for plot of phase space trajectory.
First game version

Now a signal going into A0 from any of a variety of voltage divider and
FSR circuits "drives" the system.  No virtual drive.   Should be able
to be pumped, but initial version is wonky.