An USB isolator helps eradicate floor loops and minimizes electromagnetic interference (EMI) involving the computer as well as the related gadget. 1x GND 3V3 (P2 with 2 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 https://steelex516jry6.sunderwiki.com/user