An USB isolator will help eliminate ground loops and reduces electromagnetic interference (EMI) in between the pc and also the linked machine. 1x GND 3V3 (P2 with 2 pins two.54mm) connector can be utilized to electrical power externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in https://hydrabus40617.livebloggs.com/39522167/details-fiction-and-hydrabus