An USB isolator helps remove floor loops and reduces electromagnetic interference (EMI) amongst the pc as well as the related gadget. 1x GND 3V3 (P2 with two pins 2.54mm) connector can be employed to energy externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in that case https://ericj949rjz5.blogthisbiz.com/profile