This may have come up before, and if it has, I apologized for the reposting of this.
I have an idea for improving the POV display that Ben built. Instead of just a single tab to indicate the start of the display cycle, why not create a long tab that indicates the start, and then a series of equally spaced short tabs, each indicating a new row to be displayed.
That way, as the wheel spins, the "start bit" gets set, and the microprocessor knows to start from the beginning. Then, as each short tab passes through, it increments a counter by 1, and displays that line, until the short tab is done.
If you can imagine taking the wheel, and straightening it out, the tabs might look like this:
_____ _ _ _ _ _ _ _ _ _ _ _
__| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_____
START 1 2 3 4 5 6 7 8 9 10 11
Done like this, the microprocessor doesn't have to care about the speed of the wheel, and even minor variations in speed will not mess up the location of the displayed "dots."
I'd love to see Ben revisit this.
Rick