So the loop is:
1) Clock out a row of R, G, B values for the number of panels you have linked together (64 x n)
2) Turn off the LEDs on that row (enable goes low)
3) Latch the value
4) Select the next row
5) Turn on the display (enable goes high)
(my repo which does this: https://github.com/ChuckM/1bitsy-examples/tree/master/demos/... )
Since there are 16 "rows" multiplexed on to one "row driver" you need to at least clock out a set of all the rows every mS to get a 60Hz refresh rate (or every 250uS for a 240hz rate).
It is "easy" to do 3 bit RGB color (8 colors) since each value in R, G, and B has one bit. To get shades you need to PWM the bits and that consumes more bandwidth (with the 240Hz I can get a nominal 4 'intensities' per color by PWM'ing within the 60 fps rate, more by PWMing across a longer period. (which leads to interesting effects btw).
The panels all come with these neodymium magnetic feet so you can just put up a piece of 20ga sheet and stick up your display very simply.
On the video I expect it is a camera problem, the LEDs turn off pretty much instantly. The only caveat to that would be propagation from board to board of the 'enable' line but that is less than a microsecond.
