Arduino Nano ESP32 - RFID

This tutorial provides instructions on how to use Arduino Nano ESP32 with RC522 RFID/NFC reader to read the information from RFID/NFC tag.

Hardware Preparation

1×Arduino Nano ESP32
1×USB Cable Type-C
1×RFID/NFC RC522 Kit (reader + tags)
1×RFID Key Fob
1×Jumper Wires
1×(Optional) DC Power Jack
1×(Recommended) Screw Terminal Adapter for Arduino Nano

Or you can buy the following sensor kits:

1×DIYables Sensor Kit (30 sensors/displays)
1×DIYables Sensor Kit (18 sensors/displays)
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you. We appreciate your support.

Overview of RFID-RC522 Module


RFID-RC522 module Pinout

The RFID-RC522 module has 8 pins, some pins are shared among three communication interfaces: SPI, I2C, UART. At a time, only one communication mode can be used. The pin are:

  • GND pin: connect this pin to GND (0V)
  • VCC pin: connect this pin to VCC (3.3)
  • RST pin: is a pin for reset and power-down. When this pin goes low, hard power-down is enabled. On the rising edge, the module is reset.
  • IRQ pin: is an interrupt pin that can alert the Arduino Nano ESP32 when RFID tag comes into its detection range.
  • MISO/SCL/TX pin: works as:
    • MISO pin if SPI interface is enabled
    • SCL pin if I2C interface is enabled
    • TX pin if UART interface is enabled.
  • MOSI pin: works as MOSI if SPI interface is enabled.
  • SCK pin: works as SCK if SPI interface is enabled
  • SS/SDA/RX pin: works as:
    • SS pin if SPI interface is enabled
    • SDA pin when I2C interface is enabled
    • RX pin when UART interface is enabled.

    ※ NOTE THAT:

    • The pins order can vary according to manufacturers. ALWAYS use the labels printed on the module. The above image shows the pinout of the modules from DIYables manufacturer.
    • The RFID-RC522 module works with 3.3V. Do not connect the RFID-RC522 module's VCC pin to 5V. 5V can burn the RFID-RC522 module.
    • This tutorial uses SPI interface for communication between Arduino Nano ESP32 and RFID-RC522 module.

Wiring Diagram

The wiring diagram between Arduino Nano ESP32 and RFID RC522

This image is created using Fritzing. Click to enlarge image

The wiring table between RFID/NFC RC522 Module and Arduino Nano ESP32

RFID/NFC RC522 Arduino Nano ESP32
SS → D10
SCK → D13
MOSI → D11
MISO → D12
IRQ not connected
RST → D5
VCC → 3.3V

Arduino Nano ESP32 RFID/NFC Code

/* * This Arduino Nano ESP32 code was developed by * * This Arduino Nano ESP32 code is made available for public use without any restriction * * For comprehensive instructions and wiring diagrams, please visit: * */ #include <SPI.h> #include <MFRC522.h> #define SS_PIN D10 // Arduino Nano ESP32 pin connected to RC522's SS pin #define RST_PIN D5 // Arduino Nano ESP32 pin connected to RC522's RST pin MFRC522 rfid(SS_PIN, RST_PIN); void setup() { Serial.begin(9600); SPI.begin(); // init SPI bus rfid.PCD_Init(); // init MFRC522 Serial.println("Tap an RFID/NFC tag on the RFID-RC522 reader"); } void loop() { if (rfid.PICC_IsNewCardPresent()) { // new tag is available if (rfid.PICC_ReadCardSerial()) { // NUID has been readed MFRC522::PICC_Type piccType = rfid.PICC_GetType(rfid.uid.sak); Serial.print("RFID/NFC Tag Type: "); Serial.println(rfid.PICC_GetTypeName(piccType)); // print UID in Serial Monitor in the hex format Serial.print("UID:"); for (int i = 0; i < rfid.uid.size; i++) { Serial.print(rfid.uid.uidByte[i] < 0x10 ? " 0" : " "); Serial.print(rfid.uid.uidByte[i], HEX); } Serial.println(); rfid.PICC_HaltA(); // halt PICC rfid.PCD_StopCrypto1(); // stop encryption on PCD } } }

Detailed Instructions

  • If this is the first time you use Arduino Nano ESP32, see how to setup environment for Arduino Nano ESP32 on Arduino IDE.
  • Open the Library Manager by clicking on the Library Manager icon on the left navigation bar of Arduino IDE
  • Type “MFRC522” on the search box, then look for the library by GithubCommunity
  • Install the library by clicking on Install button.
Arduino Nano ESP32 MFRC522 library
  • Copy the above code and paste it to Arduino IDE.
  • Compile and upload code to Arduino Nano ESP32 board by clicking Upload button on Arduino IDE
  • Open Serial Monitor on Arduino IDE
How to open serial monitor on Arduino IDE
  • Tap several RFID/NFC tags on RFID-RC522 module
  • See the UID printed on Serial Monitor
Tap an RFID/NFC tag on the RFID-RC522 reader RFID/NFC tag Type: MIFARE 1KB UID: 2B B8 59 B1 RFID/NFC tag Type: MIFARE Ultralight or Ultralight C UID: 15 75 46 7A 2C 5B 7E
Autoscroll Show timestamp
Clear output
9600 baud  

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