WSAL16958 – PN532 NFC HAT/en

Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

Summary

The PN532 NFC HAT adds NFC capability to the Raspberry Pi via I2C, SPI or UART. The module is based on the PN532 chip operating at 13.56 MHz and supports ISO/IEC 14443A/B and MIFARE cards.

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WSAL16958 – PN532 NFC HAT for Raspberry Pi, I2C / SPI / UART

Technical overview

Operating voltage: 3.3 V / 5 V; factory serial baud rate 115200 bps
Supported standards: ISO/IEC 14443A, MIFARE; ISO/IEC 14443B in reader mode
The PN532 chip contains a C51 microcontroller core with 40 KB ROM and 1 KB RAM
Three interfaces selectable via jumpers (I0/I1) and DIP switch: SPI, I2C or UART
SPI mode: I0=L, I1=H; NSS to D4 (BCM); RSTPDN to D20
UART mode: I0=L, I1=L; TX/RX to the Pi's serial pins
I2C mode: I0=H, I1=H; SCL/SDA to the Pi's I2C pins
Python and C demo code located under ~/raspberrypi/ after extracting the 7z archive
Module wake-up requires sending a fixed HEX frame over the serial interface
Expected result: UID of a nearby card is printed

Commands and examples – verify before use:

sudo raspi-config
cd ~/raspberrypi/python/ && sudo python3 example_get_uid.py
cd ~/raspberrypi/c/example/ && sudo make && ./rpi_get_uid.exe
wget https://files.waveshare.com/upload/6/67/pn532-nfc-hat-code.7z && 7z x Pn532-nfc-hat-code.7z -r -o./Pn532-nfc-hat-code

Notes and version constraints

The module can only read/write unencrypted or known-password protected cards; encrypted cards cannot be cracked
Simulated cards have their first ID byte fixed to 0x08
I2C communication may fail when multiple I2C devices are connected because the PN532 may use Clock Stretching
If D4 is used by other programs, SPI should not be used
The demo expects specific pin assignments; deviations require manual adjustment
Testing without a Raspberry Pi requires a USB-to-serial adapter
Version-sensitive steps: demo files must be adapted per board type

Source and revision record

PN532 NFC HAT - Waveshare Wiki
Source revision: 107792
Captured: 2026-08-31T03:56:51+00:00
SHA-256: bd93d607202f676084e7aee7278fa4496113854c09216f111ca49874e8ffb1a4