Notes concerning “Input devices”

• A resistive-capacitive trackpad made from garbage and three ADC microcontroller pins 2013-05-17 (updated 2013-05-20) (17 minutes)
• Trellis-coded buttons to run a whole keyboard off two microcontroller pins 2013-05-17 (updated 2019-06-13) (30 minutes)
• Keyboard-powered computers 2014-10-25 (updated 2018-10-28) (26 minutes)
• Coinductive keyboard 2016-07-30 (4 minutes)
• Quasimode keyboard 2018-07-14 (24 minutes)