Desk of Ladyada – E-Ink Experimentation Plus a Simple Moisture Sensor

(Re-broadcast, LIVE was not working for all social media on Sunday night, so here ya go! This week at our desk, we spent a lot of our focused engineering time working on e-paper display drivers. These displays are a lot more annoying than TFTs, which have settled on standardized MIPI command sets. Also, they have custom "waveforms" used to configure the refresh technique. By default, we use the built-in waveforms from OTP memory, but it's possible to load new waveforms, letting us do funky stuff like coax 4-grayscale out of a "monochrome" display. We also designed a simple moisture sensor PCB for an ultra-low-cost kit to be used by students—sometimes it's okay to under-design for cost reasons!