An USB isolator assists do away with ground loops and lowers electromagnetic interference (EMI) between the computer and also the connected system. 1x GND 3V3 (P2 with two pins two.54mm) connector can be used to electricity externally the WCH CH569 MCU (it is usually recommended to eliminate the P4/SHUNT in https://miriamc727ldu3.wikissl.com/user