Adafruit PN532 NFC/RFID

Name: Adafruit PN532 NFC/RFID
Brand: Adafruit
Availability: InStock

AdafruitPN532

The PN532 is an NFC and RFID module used for contactless communication. It supports various protocols like TTL serial, I2C, and SPI.

Manufacturer guide / datasheet

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Specifications

Operating Voltage: 3.3V or 5V Volts
Logic Level: TTL compatible

Pinout

Pin	Name	Functions	Notes
1	GND	GND	Ground
2	VCC	POWER	Power supply, typically 3.3V or 5V.
3	SDA	I2C	I2C data line
4	SCL	I2C	I2C clock line
5	TX	UART	Transmit data for serial communication.
6	RX	UART	Receive data for serial communication.
7	GND	GND	Ground
8	VCC	POWER	Power supply, typically 3.3V or 5V.
9	SCK	SPI	Serial clock for SPI communication
10	MOSI	SPI	Master Out/Slave In for SPI.
11	MISO	SPI	Master In/Slave Out for SPI.
12	CS	SPI	Chip select line for SPI

Interactive pinout

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PN532

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Starter code

Community starter examples — minimal, unofficial, and provided to get you wiring fast. Verify against the manufacturer datasheet before relying on them.

Arduino (C++)

Arduino library: Adafruit PN532

arduino

// PN532 NFC/RFID reader (I2C) — community starter example
#include <Wire.h>
#include <Adafruit_PN532.h>

#if defined(ESP32)
  #define PN532_IRQ 4
  #define PN532_RST 5
#else
  #define PN532_IRQ 2
  #define PN532_RST 3
#endif

Adafruit_PN532 nfc(PN532_IRQ, PN532_RST);   // I2C mode

void setup() {
  Serial.begin(115200);
  nfc.begin();
  if (!nfc.getFirmwareVersion()) { Serial.println("PN532 not found"); while (1) delay(10); }
  nfc.SAMConfig();
  Serial.println("Tap an NFC tag...");
}

void loop() {
  uint8_t uid[7]; uint8_t uidLen;
  if (nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLen)) {
    Serial.print("UID bytes: "); Serial.println(uidLen);
  }
  delay(500);
}

MicroPython

MicroPython library: pn532 (a PN532 MicroPython port)

python

# PN532 NFC (ESP32, I2C) — community starter example
# lib: a PN532 MicroPython driver (e.g. Carglglz/NFC_PN532)
from machine import Pin, I2C
from pn532 import PN532_I2C
import time

i2c = I2C(0, scl=Pin(22), sda=Pin(21))
nfc = PN532_I2C(i2c)
nfc.SAM_configuration()

while True:
    uid = nfc.read_passive_target(timeout=0.5)
    if uid:
        print("UID", [hex(b) for b in uid])
    time.sleep(0.2)

Wiring

Pin	Arduino Uno R3	ESP32 DevKitC (WROOM-32)	Notes
VCC	+5V	3V3	Logic 3.3-5 V
GND	GND	GND
SDA	A4/SDA	GPIO21	I2C data (set the board's mode switch to I2C)
SCL	A5/SCL	GPIO22	I2C clock
RSTPDN	D3	GPIO5	Reset
IRQ	D2	GPIO4	Interrupt

Typical uses

NFC / RFID read & write (13.56 MHz)
Card emulation and peer-to-peer NFC