Hi there, I actually like your venture and I do think I've competencies to help you. Your application has long been submitted. 1x GND 3V3 (P2 with two pins two.54mm) connector can be employed to energy externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in that situation It's not necessarily mandatory because the 3V3 LDO IC1