The reader initializes the conversation. The RF subject is activated, and several lower level instructions are exchanged to detect a compatible card.1x GND 3V3 (P2 with two pins 2.54mm) connector may be used to ability externally the WCH CH569 MCU (it is recommended to get rid of the P4/SHUNT in that circumstance It's not obligatory as the 3V3 LDO