Introduction
When I designed the main board of the Nestronic, I was busy enough that I didn't want to hold up progress on account of other areas of the project. I basically just figured out what interface pins I might need for an input board, brought them out to a connector, and set that part aside.
I figured I'd need an I2C bus to interface with some sort of I/O expansion chip, and a few support GPIO pins. I also thought it might be neat to try experimenting with the ESP32's touch sensor capabilities, so I made sure at least one of the GPIO pins could be used for that.
(For more project background, please read the [Introduction], [Architecture], and [Prototype Assembly] blog posts.)
