pn532_readwrite_mifare.py

# SPDX-FileCopyrightText: <text> 2015 Tony DiCola, Roberto Laricchia,
# and Francesco Crisafulli, for Adafruit Industries </text>

# SPDX-License-Identifier: MIT

# Example of detecting and reading a block from a MiFare classic NFC card.

"""
This example shows connecting to the PN532 and writing & reading a mifare classic
type RFID tag
"""

import board
import busio

# Additional import needed for I2C/SPI
# from digitalio import DigitalInOut
#
# NOTE: pick the import that matches the interface being used
#
from adafruit_pn532.adafruit_pn532 import MIFARE_CMD_AUTH_B
from adafruit_pn532.i2c import PN532_I2C

# from adafruit_pn532.spi import PN532_SPI
# from adafruit_pn532.uart import PN532_UART

# I2C connection:
i2c = busio.I2C(board.SCL, board.SDA)

# Non-hardware reset/request with I2C
pn532 = PN532_I2C(i2c, debug=False)

# With I2C, we recommend connecting RSTPD_N (reset) to a digital pin for manual
# harware reset
# reset_pin = DigitalInOut(board.D6)
# On Raspberry Pi, you must also connect a pin to P32 "H_Request" for hardware
# wakeup! this means we don't need to do the I2C clock-stretch thing
# req_pin = DigitalInOut(board.D12)
# pn532 = PN532_I2C(i2c, debug=False, reset=reset_pin, req=req_pin)

# SPI connection:
# spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
# cs_pin = DigitalInOut(board.D5)
# pn532 = PN532_SPI(spi, cs_pin, debug=False)

# UART connection
# uart = busio.UART(board.TX, board.RX, baudrate=115200, timeout=0.1)
# pn532 = PN532_UART(uart, debug=False)

ic, ver, rev, support = pn532.firmware_version
print(f"Found PN532 with firmware version: {ver}.{rev}")

# Configure PN532 to communicate with MiFare cards
pn532.SAM_configuration()

print("Waiting for RFID/NFC card to write to!")

key = b"\xff\xff\xff\xff\xff\xff"

while True:
    # Check if a card is available to read
    uid = pn532.read_passive_target(timeout=0.5)
    print(".", end="")
    # Try again if no card is available.
    if uid is not None:
        break

print("")

print("Found card with UID:", [hex(i) for i in uid])
print("Authenticating block 4 ...")

authenticated = pn532.mifare_classic_authenticate_block(uid, 4, MIFARE_CMD_AUTH_B, key)
if not authenticated:
    print("Authentication failed!")

# Set 16 bytes of block to 0xFEEDBEEF
data = bytearray(16)
data[0:16] = b"\xfe\xed\xbe\xef\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"

# Write 16 byte block.
pn532.mifare_classic_write_block(4, data)
# Read block #6
print(
    "Wrote to block 4, now trying to read that data:",
    [hex(x) for x in pn532.mifare_classic_read_block(4)],
)