Finally ! Here comes my strategy to control the flipdot display. This is the control board prototype, and drives ONE display. Each display will have it's own control board and can be daisy chained (ie, only one micro controller needed and it will control all the displays stacked together.
It's still a prototype as I'm not sure it will work (it would be too good if it worked at first try). Also I still have to design the power supply for the board logic chips. For now I'm using a cheap eBay switching voltage regulator to provide 3.3V or 5V to the ICs from the 24V supply, but this will be integrated in the design in the final version. The ESP32 being 3.3V and the chips on the display being 5V, I'll have to do some level shifting in the final design (I keep this for later once I'm sure it works).
I tried to annotate as much as I could to help follow the logic of the board, but next log will go more in depth into the chosen ICs and describe the overall functioning.
Available in PDF version for higher quality.