I recently shared a link on Discord to a talk I did about two years ago to the Silicon Valley Forth Interest Group about steno, Arduino, and Forth. This was before I'd made the first stenomod, but shows me working my way up to it. I'm posting it here too, for people who aren't on Discord but might have some interest.
My part is about an hour in the middle of three, but that link should start at the beginning of my talk. It's roughly in three sections. 1. Stenography 2. Making a keyboard by hand using an Arduino 3. Programming the firmware in Forth. So pick and choose based on what your interests are.