I am trying to get the Pn532 module working on the esp32, first I tried to get it working with i2c and had some "success"(it worked, but as soon as I had another i2c device, in my case a display, 90% of the time it refused to work) and after some research, it's mentioned in the github repo the module doesnt work with multiple devices attached on the i2c bus. Now I am trying to get it working trough spi, but it doesn't get detected. Code: readMirafe example from the Adafruit Pn532 Library, but I modified the pins from line 42-45

    @file     readMifare.pde
    @author   Adafruit Industries
    @license  BSD (see license.txt)
    This example will wait for any ISO14443A card or tag, and
    depending on the size of the UID will attempt to read from it.
    If the card has a 4-byte UID it is probably a Mifare
    Classic card, and the following steps are taken:
    - Authenticate block 4 (the first block of Sector 1) using
      the default KEYA of 0XFF 0XFF 0XFF 0XFF 0XFF 0XFF
    - If authentication succeeds, we can then read any of the
      4 blocks in that sector (though only block 4 is read here)
    If the card has a 7-byte UID it is probably a Mifare
    Ultralight card, and the 4 byte pages can be read directly.
    Page 4 is read by default since this is the first 'general-
    purpose' page on the tags.
This is an example sketch for the Adafruit PN532 NFC/RFID breakout boards
This library works with the Adafruit NFC breakout 
  ----> https://www.adafruit.com/products/364
Check out the links above for our tutorials and wiring diagrams 
These chips use SPI or I2C to communicate.
Adafruit invests time and resources providing this open source code, 
please support Adafruit and open-source hardware by purchasing 
products from Adafruit!
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_PN532.h>

// If using the breakout with SPI, define the pins for SPI communication.
#define PN532_SCK  (18)
#define PN532_MISO (19)
#define PN532_MOSI (23)
#define PN532_SS   (27)

// If using the breakout or shield with I2C, define just the pins connected
// to the IRQ and reset lines.  Use the values below (2, 3) for the shield!
#define PN532_IRQ   (2)
#define PN532_RESET (3)  // Not connected by default on the NFC Shield

// Uncomment just _one_ line below depending on how your breakout or shield
// is connected to the Arduino:

// Use this line for a breakout with a software SPI connection (recommended):
Adafruit_PN532 nfc(PN532_SCK, PN532_MISO, PN532_MOSI, PN532_SS);

// Use this line for a breakout with a hardware SPI connection.  Note that
// the PN532 SCK, MOSI, and MISO pins need to be connected to the Arduino's
// hardware SPI SCK, MOSI, and MISO pins.  On an Arduino Uno these are
// SCK = 13, MOSI = 11, MISO = 12.  The SS line can be any digital IO pin.
//Adafruit_PN532 nfc(PN532_SS);

// Or use this line for a breakout or shield with an I2C connection:
//Adafruit_PN532 nfc(PN532_IRQ, PN532_RESET);

void setup(void) {
  while (!Serial) delay(10); // for Leonardo/Micro/Zero



  uint32_t versiondata = nfc.getFirmwareVersion();
  if (! versiondata) {
    Serial.print("Didn't find PN53x board");
    while (1); // halt
  // Got ok data, print it out!
  Serial.print("Found chip PN5"); Serial.println((versiondata>>24) & 0xFF, HEX); 
  Serial.print("Firmware ver. "); Serial.print((versiondata>>16) & 0xFF, DEC); 
  Serial.print('.'); Serial.println((versiondata>>8) & 0xFF, DEC);
  // configure board to read RFID tags
  Serial.println("Waiting for an ISO14443A Card ...");

void loop(void) {
  uint8_t success;
  uint8_t uid[] = { 0, 0, 0, 0, 0, 0, 0 };  // Buffer to store the returned UID
  uint8_t uidLength;                        // Length of the UID (4 or 7 bytes depending on ISO14443A card type)
  // Wait for an ISO14443A type cards (Mifare, etc.).  When one is found
  // 'uid' will be populated with the UID, and uidLength will indicate
  // if the uid is 4 bytes (Mifare Classic) or 7 bytes (Mifare Ultralight)
  success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength);
  if (success) {
    // Display some basic information about the card
    Serial.println("Found an ISO14443A card");
    Serial.print("  UID Length: ");Serial.print(uidLength, DEC);Serial.println(" bytes");
    Serial.print("  UID Value: ");
    nfc.PrintHex(uid, uidLength);
    if (uidLength == 4)
      // We probably have a Mifare Classic card ... 
      Serial.println("Seems to be a Mifare Classic card (4 byte UID)");
      // Now we need to try to authenticate it for read/write access
      // Try with the factory default KeyA: 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF
      Serial.println("Trying to authenticate block 4 with default KEYA value");
      uint8_t keya[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
      // Start with block 4 (the first block of sector 1) since sector 0
      // contains the manufacturer data and it's probably better just
      // to leave it alone unless you know what you're doing
      success = nfc.mifareclassic_AuthenticateBlock(uid, uidLength, 4, 0, keya);
      if (success)
        Serial.println("Sector 1 (Blocks 4..7) has been authenticated");
        uint8_t data[16];
        // If you want to write something to block 4 to test with, uncomment
        // the following line and this text should be read back in a minute
        //memcpy(data, (const uint8_t[]){ 'a', 'd', 'a', 'f', 'r', 'u', 'i', 't', '.', 'c', 'o', 'm', 0, 0, 0, 0 }, sizeof data);
        // success = nfc.mifareclassic_WriteDataBlock (4, data);

        // Try to read the contents of block 4
        success = nfc.mifareclassic_ReadDataBlock(4, data);
        if (success)
          // Data seems to have been read ... spit it out
          Serial.println("Reading Block 4:");
          nfc.PrintHexChar(data, 16);
          // Wait a bit before reading the card again
          Serial.println("Ooops ... unable to read the requested block.  Try another key?");
        Serial.println("Ooops ... authentication failed: Try another key?");
    if (uidLength == 7)
      // We probably have a Mifare Ultralight card ...
      Serial.println("Seems to be a Mifare Ultralight tag (7 byte UID)");
      // Try to read the first general-purpose user page (#4)
      Serial.println("Reading page 4");
      uint8_t data[32];
      success = nfc.mifareultralight_ReadPage (4, data);
      if (success)
        // Data seems to have been read ... spit it out
        nfc.PrintHexChar(data, 4);
        // Wait a bit before reading the card again
        Serial.println("Ooops ... unable to read the requested page!?");

My wiring is the following

(PN523 Module->esp32):
SCK  -> D18;
MSO  -> D19;
MOSI -> D23;
SS   -> D27

And yes, the board is in SPI mode(the dip switch). Thank you!

  • try hw SPI. now you use the library in software SPI mode
    – Juraj
    Commented Nov 7, 2021 at 6:56
  • 2
    Same issues here, same setup, any news? Commented Nov 26, 2021 at 20:22
  • The project has just been sitting here, collecting dust. Didn't have the time to look into it
    – Ferferite
    Commented Nov 27, 2021 at 22:03
  • @AllanAlmeida found the solution! github.com/adafruit/Adafruit-PN532/issues/…
    – Ferferite
    Commented Dec 26, 2021 at 13:18

2 Answers 2


Got it working by running the module in VSPI and modifying the library a bit: https://github.com/adafruit/Adafruit-PN532/issues/80#issuecomment-649915457


There is a switch on your PN5322 by default it is set to 0, 0. Switch to the mode of communication you are using.

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