Application - RFID, RC522

Hardware

RC522     RPi3
=== = ===
SDA   --   24
SCK   --   23
MOSI  --   19
MISO  --   21
IRQ   --   16
GND   --   GND
PST   --   29
VCC   --   3.3v

Classic 1K Mifare

Has 16 sectors, each sector has 4 blocks, each block has 16 bytes
=== = ===
sector    [0..15]
block     [0..3]
byte      16
=== = ===
total size: 16x16x16 bytes = 4k bytes