Sensors

RFID RC522 Module 13.56MHz

The RFID RC522 module (MFRC522 chip) reads and writes RFID/NFC tags operating at 13.56 MHz. It communicates with microcontrollers over an SPI interface using lines for chip-select (SDA/NSS), clock (SCK), data (MOSI/MISO), plus reset (RST) and an optional interrupt (IRQ), powered from 3.3V.

Width: 63.5 mm

Pinout — RFID RC522 Module 13.56MHz

Pin	Signal	Description
`SDA`	chip-select	SPI slave-select/chip-select input for the RC522, often labeled SDA on this module.
`SCK`	SCK	SPI clock input from the microcontroller to the RC522.
`MOSI`	MOSI	SPI data input to the RC522 from the microcontroller.
`MISO`	MISO	SPI data output from the RC522 to the microcontroller.
`IRQ`	interrupt	Interrupt output from the RC522 for events such as card detection or FIFO status.
`GND`	ground	Ground reference for power and logic signals.
`RST`	reset	Reset/power-down control input for the RC522; drive low to reset.
`3.3V`	power	3.3 V power supply input for the RC522 module; do not power from 5 V.

Example wiring diagram — RFID RC522 Module 13.56MHz

From	To	Wire
`board:3.3V`	`x1:3.3V`	darkorange
`board:GND`	`x1:GND`	black
`board:D10`	`x1:SDA`	green
`board:D13`	`x1:SCK`	blue
`board:D11`	`x1:MOSI`	yellow
`board:D12`	`x1:MISO`	purple
`board:D9`	`x1:RST`	cyan

Example Arduino code — RFID RC522 Module 13.56MHz

This example was written and compile-checked for the arduino-uno. Codey Online adapts it to any other supported board for you.

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

#define SS_PIN 10
#define RST_PIN 9

MFRC522 mfrc522(SS_PIN, RST_PIN);

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ;
  }

  SPI.begin();
  mfrc522.PCD_Init();

  Serial.println(F("RC522 RFID reader ready."));
  Serial.println(F("Tap an NFC/RFID card or tag near the reader."));
}

void loop() {
  if (!mfrc522.PICC_IsNewCardPresent()) {
    return;
  }

  if (!mfrc522.PICC_ReadCardSerial()) {
    return;
  }

  Serial.print(F("Card UID: "));
  for (byte i = 0; i < mfrc522.uid.size; i++) {
    if (mfrc522.uid.uidByte[i] < 0x10) {
      Serial.print(F("0"));
    }
    Serial.print(mfrc522.uid.uidByte[i], HEX);
    if (i < mfrc522.uid.size - 1) {
      Serial.print(F(" "));
    }
  }
  Serial.println();

  mfrc522.PICC_HaltA();
  mfrc522.PCD_StopCrypto1();
}

RFID RC522 Module 13.56MHz

Pinout — RFID RC522 Module 13.56MHz

Example wiring diagram — RFID RC522 Module 13.56MHz

Example Arduino code — RFID RC522 Module 13.56MHz

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