Howdy, I actually like your venture and I do think I have competencies that can assist you. Your software is submitted. 1x GND 3V3 (P2 with 2 pins 2.54mm) connector may be used to power externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in that case It's not required as the 3V3 LDO IC1 is safeguarded versus reverse present)