MicroPython MFRC522

An MFRC522 device driver library for MicroPython.

Introduction

The MFRC522 is a specialized chip that reads and writes RFID data over SPI. It is available on Amazon.

Installation & Dependencies

This driver depends on:

• MicroPython

Usage Examples

from machine import Pin, SoftSPI

from micropython_mfrc522.mfrc522 import MFRC522

sck = Pin(18, Pin.OUT)
copi = Pin(23, Pin.OUT) # Controller out, peripheral in
cipo = Pin(19, Pin.OUT) # Controller in, peripheral out
spi = SoftSPI(baudrate=100000, polarity=0, phase=0, sck=sck, mosi=copi, miso=cipo)
sda = Pin(21, Pin.OUT)
reader = MFRC522(spi, sda)

print('Place Card In Front Of Device To Read Unique Address')
print('')

while True:
    try:
        (status, tag_type) = reader.request(reader.CARD_REQIDL)
        if status == reader.OK:
            (status, raw_uid) = reader.anticoll()
            if status == reader.OK:
                print('New Card Detected')
                print('  - Tag Type: 0x%02x' % tag_type)
                print('  - uid: 0x%02x%02x%02x%02x' % (raw_uid[0], raw_uid[1], raw_uid[2], raw_uid[3]))
                print('')
                if reader.select_tag(raw_uid) == reader.OK:
                    key = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]
                    if reader.auth(reader.AUTH, 8, key, raw_uid) == reader.OK:
                        print("Address Data: %s" % reader.read(8))
                        reader.stop_crypto1()
                    else:
                        print("AUTH ERROR")
                else:
                    print("FAILED TO SELECT TAG")
    except KeyboardInterrupt:
        break

from machine import Pin, SoftSPI

from micropython_mfrc522.mfrc522 import MFRC522

sck = Pin(18, Pin.OUT)
copi = Pin(23, Pin.OUT) # Controller out, peripheral in
cipo = Pin(19, Pin.OUT) # Controller in, peripheral out
spi = SoftSPI(baudrate=100000, polarity=0, phase=0, sck=sck, mosi=copi, miso=cipo)
sda = Pin(21, Pin.OUT)
reader = MFRC522(spi, sda)

print('Place Card In Front Of Device To Write Unique Address')
print('')

while True:
    try:
        (status, tag_type) = reader.request(reader.CARD_REQIDL)
        if status == reader.OK:
            (status, raw_uid) = reader.anticoll()
            if status == reader.OK:
                print('New Card Detected')
                print('  - Tag Type: 0x%02x' % tag_type)
                print('  - UID: 0x%02x%02x%02x%02x' % (raw_uid[0], raw_uid[1], raw_uid[2], raw_uid[3]))
                print('')
                if reader.select_tag(raw_uid) == reader.OK:
                    key = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]
                    if reader.auth(reader.AUTH, 8, key, raw_uid) == reader.OK:
                        # Write your unique address here
                        status = reader.write(8, b'\x08\x06\x07\x05\x03\x00\x09\x00\x00\x00\x00\x00\x00\x00\x00\x00')
                        reader.stop_crypto1()
                        if status == reader.OK:
                            print('Data Written To Card...')
                        else:
                            print('FAILED TO WRITE DATA')
                    else:
                        print('AUTH ERROR')
                else:
                    print('FAILED TO SELECT TAG')
    except KeyboardInterrupt:
        break

Hardware Set-up

Connect 3.3 V to 3.3 V power source, GND to ground, SCK, COPI, CIPO, SPI and SDA to the appropriate pins.

Basics

You must import machine, SoftSPI, Pin and the library:

from machine import SoftSPI, Pin

To set-up the device to gather data, initialize the SoftI2CDevice using SDA, SCK, COPI and CIPO pins and then initialize the library to provide new data ready to be read or write.

Read

To read the unique address data:

print("Address Data: %s" % reader.read(8))

Write

To write the unique address data:

status = reader.write(8, b'\x08\x06\x07\x05\x03\x00\x09\x00\x00\x00\x00\x00\x00\x00\x00\x00')

Run Tests in REPL

import unittest
unittest.main('test_mfrc522')

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT License