An USB isolator allows get rid of floor loops and cuts down electromagnetic interference (EMI) among the pc and also the related device. 1x GND 3V3 (P2 with 2 pins 2.54mm) connector may be used to power externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in https://conradb627kbs2.eqnextwiki.com/user