I'm having a hard time trying to understand MFRC522 datasheet and procedure to read UID, authentication and so on. In datasheet item 10.3.1.2, there is a command "Mem" which transfers 25 bytes from FIFO buffer to the internal buffer. But what is this "internal buffer"? What is its size? what it stores? There's no mention of internal buffer anywhere in datasheet except for Mem command, but it doesn't explain it. Can anybody help me?
The Mem command either transfers data from internal buffer to FIFO or vice versa depending on FIFO's length. It would be easier to refer to the NFC Reader Library and the software examples available. The Library for PN512 will work for this device with the corresponding definition for this reader.
Hope this helps.