Cool Link
GitHub - Dieu-de-l-elec/AngstromIO-devboard: AngstromIO, one of the smallest devboards out there, barely longer than a USB C connector, based on the Attiny1616 MCU. And a dual CH340 board for programming and debugging, and another devboard, based on the CH32V003 · GitHub github.com

github.com/Dieu-de-l-elec/AngstromIO-devboard