Simply used as a debug tool to connect a PC COM port through isolation.
Expects power from DUT.
Shout out to Guan Yang (wherever you are) for the original 231X KiCAD project from 2013 I started from.
Bare Bones USB Mini to isolated UART (GND,RX,TX,VCC) through a FT230XS USB to UART device and a SI8422AB isolator.