So you wanted to design your own module, but you are not an expert in hardware nor software design? Maybe then have a look at eurorack-blocks:
The
eurorack-blocksproject allows to develop your own custom Eurorack module for either prototyping or fun in the comfort of your day-to-day IDE with the C++ or Faust language, or using the Cycling '74 Max environment, testing and debugging in a virtual Eurorack environment, and when ready, to auto-magically generate all the needed files to manufacture the eurorack module for you to use in a real Eurorack modular system.
The virtual eurorack environment mentioned is VCV Rack.