Open-source boards designed in KiCad by notthetup on GitHub, from 4 repositories. A board’s address here is its repository’s there.
notthetup/draw
Power and Current Draw meter
notthetup/esp232
ESP32 + RS232 = 💰
notthetup/2bucks
A simple PCB with 2 DCDC (buck) regulators
notthetup/GettingToBlinky4
Getting to Blinky 4