Documentation

// RC522 RFID - Arduino Example
// Library: MFRC522 by GithubCommunity

#include <SPI.h>
#include <MFRC522.h>

#define SS_PIN 10
#define RST_PIN 9

MFRC522 rfid(SS_PIN, RST_PIN);

void setup() {
  Serial.begin(9600);
  SPI.begin();
  rfid.PCD_Init();
  Serial.println("Tap an RFID card or fob...");
}

void loop() {
  if (!rfid.PICC_IsNewCardPresent() || !rfid.PICC_ReadCardSerial()) return;

  Serial.print("UID: ");
  for (byte i = 0; i < rfid.uid.size; i++) {
    if (rfid.uid.uidByte[i] < 0x10) Serial.print("0");
    Serial.print(rfid.uid.uidByte[i], HEX);
    Serial.print(" ");
  }
  Serial.println();

  rfid.PICC_HaltA();
  rfid.PCD_StopCrypto1();
}

#!/usr/bin/env python3
# Install: pip install mfrc522 spidev
# Enable SPI: sudo raspi-config -> Interface Options -> SPI

from mfrc522 import SimpleMFRC522
import time

reader = SimpleMFRC522()

print("Tap an RFID card...")
try:
    while True:
        id, text = reader.read_no_block()
        if id:
            print(f"UID: {id}  text: {text!r}")
            time.sleep(1)
        time.sleep(0.1)
except KeyboardInterrupt:
    pass

# RC522 on Pico - MicroPython
# Use the micropython-mfrc522 library by danjperron
# https://github.com/danjperron/micropython-mfrc522

from mfrc522 import MFRC522
import utime

reader = MFRC522(spi_id=0, sck=18, mosi=19, miso=16, cs=17, rst=20)

print("Tap an RFID card...")
while True:
    (stat, tag_type) = reader.request(reader.REQIDL)
    if stat == reader.OK:
        (stat, uid) = reader.SelectTagSN()
        if stat == reader.OK:
            print('UID:', '-'.join(['{:02X}'.format(x) for x in uid]))
            utime.sleep(1)
    utime.sleep_ms(100)