Hi, I really like your task and I think I have skills that can assist you. Your application has long been submitted. 1x GND 3V3 (P2 with 2 pins two.54mm) connector can be employed to electrical power externally the WCH CH569 MCU (it is usually recommended to remove the P4/SHUNT in that case It is far from necessary as being the 3V3 LDO IC1 is pr