I'd start by building around the TPIC6B595 chip.
While that would be a good chip to control the system with, I think ultimately one needs to start by first verifying if my valve idea would even work!
;D
The controlling code and hardware can come later; what should be done is to build a simplified singular form of the valve. The idea is to have a valve that operates so that singular drops can be formed, with no pressure (other than gravity) behind the water droplets. Plus, the valve needs to operate at high speeds/cycles.
Such valves are possible to purchase, and I am sure that the videos of these displays use such valves; but they are anything but cheap. So my goal was to come up with a solution that could be implemented cheaply (though not easily).
If a singular valve worked (or if the idea could be used to make a cheap valve that worked), with perhaps it being controlled by an Arduino via a simple transistor switch - it would prove the concept, and that perfected valve could then be used to build the larger device.
Which leads me to wonder if a singular form of the valve wouldn't perhaps be useful in some manner to those who do water-drop photography...hmm.
