The controller board uses an D1 mini ESP8266 microcontroller to control a number of outputs going to the displays, and read inputs connected to the display encodes, which give the current position of the rotor with the split flaps.
The controller can address 8 lines and 15 columns, for a total of 120 characters. With the displays currently available to us, we're using 6 lines with 11 columns, for a total of 66 characters.
The schematic flipflap-sch.pdf and the assembly diagram flipflap-pcb.pdf show the details of the board.
An Arduino sketch can be found in arduino/flipflap.
Documentation for the split-flap display model can be found in docs/. Theory of Operation tries to explain how a microcontroller can control the displays.
- https://arduino.github.io/arduino-cli/0.29/getting-started/
- https://medium.com/@thomas.kilmar/arduino-cli-with-visual-studio-code-on-macos-d2ad32ff0276
We're not the only ones working with these modules.
- Tim's SplitFlap Clock - Part I (Electronics). Unfortunately, the software part seems to never have been published.
- /ADC4 to /ADC7 are swapped when looking at the register outputs. This can easily be adjusted in the ADC cable.