PN532 NFC Module
Versatile NFC module supporting read, write, card emulation, and peer-to-peer modes.
Wiring & code for
PN532 practical reference
A more capable NFC controller than the RC522, supporting card emulation and peer-to-peer NFC in addition to basic tag reading. The PN532 handles the full range of NFC operation modes — reading and writing common tag types, emulating a card itself (so a project can act like an access card), and peer-to-peer communication with another NFC device like a smartphone — making it the preferred choice over the simpler RC522 whenever a project needs more than just read/write access-control tag scanning.
Key specifications
- Chipset: NXP PN532 NFC/RFID controller
- Operating voltage: 3.3V DC (5V-tolerant on some breakout boards with onboard level shifting — check your specific module)
- Operating current: ~100-150 mA during active RF operation
- Frequency: 13.56MHz (NFC/RFID)
- Supported tag types: ISO/IEC 14443A (Mifare Classic, Mifare Ultralight, NTAG), and FeliCa
- Operation modes: Read/write tag mode, card emulation mode, and peer-to-peer (P2P) mode for direct NFC device-to-device communication
- Read range: ~5-7cm typical, antenna-design dependent
- Interface: Selectable I2C, SPI, or UART depending on the DIP switch/solder jumper setting on the breakout board
Pinout and connection notes
Most PN532 breakout boards have a small switch or set of solder jumpers to select between I2C, SPI, and UART interface modes — double-check this setting matches your wiring and library configuration, since a mismatched mode is the most common reason a PN532 board fails to respond. I2C mode is the simplest for quick prototyping with common Arduino libraries (e.g. Adafruit's PN532 library).
- VCC: Power, 3.3-5V DC depending on breakout board
- GND: Ground
- SDA / MOSI / TX: Data line — role depends on selected interface mode (I2C/SPI/UART)
- SCL / SCK / RX: Clock or receive line — role depends on selected interface mode
- IRQ: Interrupt output, signals when a tag/device is detected
- RSTO / RSTPDN: Reset / power-down control pin
Integration checklist
- Confirm the exact part number and breakout-board revision.
- Verify supply voltage, current demand, logic levels, and signal direction against the datasheet.
- Check controller pin assignments and bus address or interface mode against the example code.
- Power up with external loads disconnected, then test signals before full integration.
- If readings or communication fail, check power and ground first, then pin mapping, interface settings, and library initialization.
Troubleshooting and reproducibility
Record the board used, wiring, library/version, supply arrangement, and measured behavior. Use the selected board-specific wiring example as the source of truth. Never assume visually similar modules share identical voltage tolerance or pin order.