user59087: I'm trying the Android Hce example in this PN532 library. I can't find how to set SDA and SCL address in the code, so I tried connecting them in CLK and SD0 pins. The serial monitor gives me "Didn't find PN53x board". Can someone help me?
    #if 0
      #include <SPI.h>
      #include <PN532_SPI.h>
      #include "PN532.h"

      PN532_SPI pn532spi(SPI, 10);
      PN532 nfc(pn532spi);
    #elif 1
      #include <PN532_HSU.h>
      #include <PN532.h>

      PN532_HSU pn532hsu(Serial1);
      PN532 nfc(pn532hsu);
    #else 
      #include <Wire.h>
      #include <PN532_I2C.h>
      #include <PN532.h>
    #endif

    void setup()
    {    
        Serial.begin(115200);
        Serial.println("-------Peer to Peer HCE--------");

        nfc.begin();

        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);

        // Set the max number of retry attempts to read from a card
        // This prevents us from waiting forever for a card, which is
        // the default behaviour of the PN532.
        //nfc.setPassiveActivationRetries(0xFF);

        // configure board to read RFID tags
        nfc.SAMConfig();
    }

    void loop()
    {
      bool success;

      uint8_t responseLength = 32;

      Serial.println("Waiting for an ISO14443A card");

      // set shield to inListPassiveTarget
      success = nfc.inListPassiveTarget();

      if(success) {

         Serial.println("Found something!");

        uint8_t selectApdu[] = { 0x00, /* CLA */
                                  0xA4, /* INS */
                                  0x04, /* P1  */
                                  0x00, /* P2  */
                                  0x07, /* Length of AID  */
                                  0xF0, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, /* AID defined on Android App */
                                  0x00  /* Le  */ };

        uint8_t response[32];  

        success = nfc.inDataExchange(selectApdu, sizeof(selectApdu), response, &responseLength);

        if(success) {

          Serial.print("responseLength: "); Serial.println(responseLength);

          nfc.PrintHexChar(response, responseLength);

          do {
            uint8_t apdu[] = "Hello from Arduino";
            uint8_t back[32];
            uint8_t length = 32; 

            success = nfc.inDataExchange(apdu, sizeof(apdu), back, &length);

            if(success) {

              Serial.print("responseLength: "); Serial.println(length);

              nfc.PrintHexChar(back, length);
            }
            else {

              Serial.println("Broken connection?"); 
            }
          }
          while(success);
        }
        else {

          Serial.println("Failed sending SELECT AID"); 
        }
      }
      else {

        Serial.println("Didn't find anything!");
      }

      delay(1000);
    }

    void printResponse(uint8_t *response, uint8_t responseLength) {

       String respBuffer;

        for (int i = 0; i < responseLength; i++) {

          if (response[i] < 0x10) 
            respBuffer = respBuffer + "0"; //Adds leading zeros if hex value is smaller than 0x10

          respBuffer = respBuffer + String(response[i], HEX) + " ";                        
        }

        Serial.print("response: "); Serial.println(respBuffer);
    }

    void setupNFC() {

      nfc.begin();

      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
      nfc.SAMConfig(); 
    } 


user59087: Solved. Set #if 1 and #elif 0.
Connected:
SCK to D5
MISO to D6
MOSI to D7
SS to D0 (and set it on pn532spi)

59087: <p>I'm trying the Android Hce example in <a href="https://github.com/elechouse/PN532" rel="nofollow noreferrer">this PN532 library</a>. I can't find how to set SDA and SCL address in the code, so I tried connecting them in CLK and SD0 pins. The serial monitor gives me "Didn't find PN53x board". Can someone help me?</p>

<pre class="lang-cpp prettyprint-override"><code>    #if 0
      #include &lt;SPI.h&gt;
      #include &lt;PN532_SPI.h&gt;
      #include "PN532.h"

      PN532_SPI pn532spi(SPI, 10);
      PN532 nfc(pn532spi);
    #elif 1
      #include &lt;PN532_HSU.h&gt;
      #include &lt;PN532.h&gt;

      PN532_HSU pn532hsu(Serial1);
      PN532 nfc(pn532hsu);
    #else 
      #include &lt;Wire.h&gt;
      #include &lt;PN532_I2C.h&gt;
      #include &lt;PN532.h&gt;
    #endif

    void setup()
    {    
        Serial.begin(115200);
        Serial.println("-------Peer to Peer HCE--------");

        nfc.begin();

        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&gt;&gt;24) &amp; 0xFF, HEX); 
        Serial.print("Firmware ver. "); Serial.print((versiondata&gt;&gt;16) &amp; 0xFF, DEC); 
        Serial.print('.'); Serial.println((versiondata&gt;&gt;8) &amp; 0xFF, DEC);

        // Set the max number of retry attempts to read from a card
        // This prevents us from waiting forever for a card, which is
        // the default behaviour of the PN532.
        //nfc.setPassiveActivationRetries(0xFF);

        // configure board to read RFID tags
        nfc.SAMConfig();
    }

    void loop()
    {
      bool success;

      uint8_t responseLength = 32;

      Serial.println("Waiting for an ISO14443A card");

      // set shield to inListPassiveTarget
      success = nfc.inListPassiveTarget();

      if(success) {

         Serial.println("Found something!");

        uint8_t selectApdu[] = { 0x00, /* CLA */
                                  0xA4, /* INS */
                                  0x04, /* P1  */
                                  0x00, /* P2  */
                                  0x07, /* Length of AID  */
                                  0xF0, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, /* AID defined on Android App */
                                  0x00  /* Le  */ };

        uint8_t response[32];  

        success = nfc.inDataExchange(selectApdu, sizeof(selectApdu), response, &amp;responseLength);

        if(success) {

          Serial.print("responseLength: "); Serial.println(responseLength);

          nfc.PrintHexChar(response, responseLength);

          do {
            uint8_t apdu[] = "Hello from Arduino";
            uint8_t back[32];
            uint8_t length = 32; 

            success = nfc.inDataExchange(apdu, sizeof(apdu), back, &amp;length);

            if(success) {

              Serial.print("responseLength: "); Serial.println(length);

              nfc.PrintHexChar(back, length);
            }
            else {

              Serial.println("Broken connection?"); 
            }
          }
          while(success);
        }
        else {

          Serial.println("Failed sending SELECT AID"); 
        }
      }
      else {

        Serial.println("Didn't find anything!");
      }

      delay(1000);
    }

    void printResponse(uint8_t *response, uint8_t responseLength) {

       String respBuffer;

        for (int i = 0; i &lt; responseLength; i++) {

          if (response[i] &lt; 0x10) 
            respBuffer = respBuffer + "0"; //Adds leading zeros if hex value is smaller than 0x10

          respBuffer = respBuffer + String(response[i], HEX) + " ";                        
        }

        Serial.print("response: "); Serial.println(respBuffer);
    }

    void setupNFC() {

      nfc.begin();

      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&gt;&gt;24) &amp; 0xFF, HEX); 
      Serial.print("Firmware ver. "); Serial.print((versiondata&gt;&gt;16) &amp; 0xFF, DEC); 
      Serial.print('.'); Serial.println((versiondata&gt;&gt;8) &amp; 0xFF, DEC);

      // configure board to read RFID tags
      nfc.SAMConfig(); 
    } 
</code></pre>
 59087: <p>Solved. Set #if 1 and #elif 0.
Connected:
SCK to D5
MISO to D6
MOSI to D7
SS to D0 (and set it on pn532spi)</p>
