I've been using the CH32V305 as a keyboard controller. (https://gitlab.com/hakfoo1/ch32v-keyboard https://gitlab.com/hakfoo1/ch32v-keyboard) It can be had on a

I've been using the CH32V305 as a keyboard controller. (https://gitlab.com/hakfoo1/ch32v-keyboard https://gitlab.com/hakfoo1/ch32v-keyboard) It can be had on a convenient breakout board for six dollars. You get GPIOs for days and workable examples to handle the heavy lifting of USB and I2C (since modern keyboards need little OLED displays :) I'm hoping the platform picks up more momentum in this particular vertical. Designs are outgrowing the tiny AVR Pro Micro and equivalent controllers, but it seems to be ending up in a thousand different ARM flavours at this point.