I connect the RFID-RC522 to Uno and it works but I connect to Leonardo , it shows the error:
MFRC522 Software Version: 0xFF (unknown)
WARNING: Communication failure, is the MFRC522 properly connected?
I followed the instruction to connect the arduino (use ICSP to replace pin 11-13 )
and use the example of this library :
how can i fix the problem ?