I am new in this site,
I want to use RC522 RFID module, equipped with NPX chip. It will be connected to Arduino UNO that works al 5 VDC.
I have read the NPX datasheet, end in pages 74 and 75 it clearly specifies the chip is not 5 VDC tolerant.
I do not have active mosfet voltage shifters, so I must connect with passive R voltage dividers.
I suppose that from the five comm lines, only four are read by the RC522 3.3 volt slave module.
Need to be connected via voltage divider resistors, for instance 510R to the line then 1K to ground, to shift down from 5 to 3.3
The fifth line (MISO) is at 3.3 volt in the slave, but this can be connected directly to the PIN12 in UNO, as it will read 3.3 volt as a HIGH condition.
Is this scheme right ?
I want to get some help before frying my 522, I am 420 km far from a dealer to replace it ?
Thanks so much