The reader initializes the communication. The RF subject is activated, and several minimal amount commands are exchanged to detect a suitable card. 1x GND 3V3 (P2 with two pins 2.54mm) connector may be used to power externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in that case It's not at all required because the 3V3 LDO I