An USB isolator can help eliminate ground loops and minimizes electromagnetic interference (EMI) involving the computer along with the connected unit. 1x GND 3V3 (P2 with two pins two.54mm) connector can be utilized to electric power externally the WCH CH569 MCU (it is recommended to get rid of the P4/SHUNT https://hydrabus20853.sunderwiki.com/1268643/hydrabus_no_further_a_mystery