I have the Grove NFC reader module and a Grove Mega Shield connected to an Arduino 2560 Mega.
Using Arduino 1.0.5.
I cut the UART to P1 trace and soldered P1 to I2C and verified that P1 and UART aren’t connected with a voltmeter and also verified that P1 and I2C are connected.
I run the ReadTag example from NDEF library and I get the error:
Didn’t find PN53x board.
I tried all 3 I2C ports on the Mega shield.