File content as of revision 1:fb72a2f7cab5:

/**************************************************************************/
/*!

    @file          main.cpp
    @author        Adafruit Industries
    @modified_by   Ben Zhang <benzh@eecs.berkeley.edu>
    @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 to communicate, 4 required to interface

Adafruit invests time and resources providing this open source code, 
please support Adafruit and open-source hardware by purchasing 
products from Adafruit!

*/
/**************************************************************************/

#include "mbed.h"
#include "Adafruit_PN532.h"

#define SS   PTD0
// PTD1 is also LED_BLUE, it will blink during SPI communication.
#define SCK  PTD1
#define MOSI PTD2
#define MISO PTD3

DigitalOut red(LED_RED);
DigitalOut green(LED_GREEN);

Serial pc(USBTX, USBRX);
Adafruit_PN532 nfc(SCK, MISO, MOSI, SS);

void loop(void);

int main() {
  pc.printf("Hello!\n");  
  // By default, red
  green = 1; red = 0;

  nfc.begin();

  uint32_t versiondata = nfc.getFirmwareVersion();
  if (! versiondata) {
    pc.printf("Didn't find PN53x board");
    while (1); // halt
  }
  // Got ok data, print it out!
  pc.printf("Found chip PN5%2X with Firmware ver. %d.%d\n",
            versiondata >> 24,
            (versiondata >> 16) & 0xFF,
            (versiondata >> 8) & 0xFF);
  
  // configure board to read RFID tags
  nfc.SAMConfig();
  
  pc.printf("Waiting for an ISO14443A Card ...\n");
  
  while(1) { loop(); }
}


void loop(void) {
  // Turn back to red  
  green = 1; red = 0;

  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) {
    // Turn off to indicate Card swipe
    green = 1; red = 1;
    // Display some basic information about the card
    pc.printf("\n\nFound an ISO14443A card\n");
    pc.printf("  UID Length: %d bytes", uidLength);
    pc.printf("  UID Value: ");
    nfc.PrintHex(uid, uidLength);
    pc.printf("\n");
    
    if (uidLength == 4)
    {
      // We probably have a Mifare Classic card ... 
      pc.printf("Seems to be a Mifare Classic card (4 byte UID)\n");
      
      // Now we need to try to authenticate it for read/write access
      // Try with the factory default KeyA: 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF
      pc.printf("Trying to authenticate block 4 with default KEYA value\n");
      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)
      {
        // Turn green to indicate success
        green = 0; red = 1;
        pc.printf("Sector 1 (Blocks 4..7) has been authenticated\n");
        uint8_t data[16];
        
        // If you want to write something to block 4 to test with, remove
        // the definition of data above, and uncomment the following lines
        /************************************************************************
        uint8_t data[16] = { 'b', 'e', 'n', ' ', 'z', 'h', 'a', 'n', 'g' };
        success = nfc.mifareclassic_WriteDataBlock (4, data);
        if (success)
        {
          // Data seems to have been read ... spit it out
          pc.printf("Data Written to Block 4:\n\t");
          nfc.PrintHexChar(data, 16);
          pc.printf("\n");
          
          // Wait a bit before reading the card again
          wait(1);
        }
        else
        {
          pc.printf("Ooops ... unable to write the requested block.\n");
        }
        return;
        ************************************************************************/
        
        // 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
          pc.printf("Reading Block 4:\n\t");
          nfc.PrintHexChar(data, 16);
          pc.printf("\n");
          
          // Wait a bit before reading the card again
          wait(1);
        }
        else
        {
          pc.printf("Ooops ... unable to read the requested block.  Try another key?\n");
        }
      }
      else
      {
        pc.printf("Ooops ... authentication failed: Try another key?\n");
      }
    }
    
    if (uidLength == 7)
    {
      // We probably have a Mifare Ultralight card ...
      pc.printf("Seems to be a Mifare Ultralight tag (7 byte UID)\n");
      
      // Try to read the first general-purpose user page (#4)
      pc.printf("Reading page 4\n");
      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);
        pc.printf("\n");
        
        // Wait a bit before reading the card again
        wait(1);
      }
      else
      {
        pc.printf("Ooops ... unable to read the requested page!?\n");
      }
    }
  }
}