I had the same problem with my DOIT ESP-WROOM-32 dev kit. I just could not get the MFRC522 board to be initialised. I connected the pins as per recommended even though you can configure the pins: #define RFID_SDA 5 #define RFID_SCK 18 #define RFID_MOSI 23 #define RFID_MISO 19 #define RFID_RST 21 Ori...