An USB isolator can help reduce floor loops and decreases electromagnetic interference (EMI) involving the computer along with the connected unit. 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://setholljf.worldblogged.com/39174792/the-fact-about-hydrabus-that-no-one-is-suggesting