Hi there, I actually like your project and I feel I've expertise to help you. Your application has long been submitted. 1x GND 3V3 (P2 with 2 pins two.54mm) connector can be used to electrical power externally the WCH CH569 MCU (it is usually recommended to remove the P4/SHUNT in https://muqtadar383asj9.dreamyblogs.com/profile