Example Code for PN532 reads the tag by Arduino

Wiring Diagram

Sample Code

/*

 # Editor : Adrian
 # Date   : 2013.04.18
 # Ver    : 0.1
 # Product: NFC Module for Arduino
 # SKU    : DFR0231

 # Description:
 # When the a card close to the device , the PC will receive the data
 # Connect the NFC Card's TXD, RXD, GND, +3.3V to Nano's D0RX, D1TX, GND, +3.3V
 # Or connect the NFC Card's TXD, RXD, GND, +5V to Nano's D0RX, D1TX, GND, +5V


 PN532 reads the tag by Arduino mega/Leonardo
 command list:

 #wake up reader
 send: 55 55 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff 03 fd d4 14 01 17 00
 return: 00 00 FF 00 FF 00 00 00 FF 02 FE D5 15 16 00

 #get firmware
 send: 00 00 FF 02 FE D4 02 2A 00
 return: 00 00 FF 00 FF 00 00 00 FF 06 FA D5 03 32 01 06 07 E8 00

 #read the tag
 send: 00 00 FF 04 FC D4 4A 01 00 E1 00
 return: 00 00 FF 00 FF 00 00 00 FF 0C F4 D5 4B 01 01 00 04 08 04 XX XX XX XX 5A 00
 XX is tag.

 */

const unsigned char wake[24]={
  0x55, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0x03, 0xfd, 0xd4, 0x14, 0x01, 0x17, 0x00};//wake up NFC module
const unsigned char firmware[9]={
  0x00, 0x00, 0xFF, 0x02, 0xFE, 0xD4, 0x02, 0x2A, 0x00};//
const unsigned char tag[11]={
  0x00, 0x00, 0xFF, 0x04, 0xFC, 0xD4, 0x4A, 0x01, 0x00, 0xE1, 0x00};//detecting tag command
const unsigned char std_ACK[25] = {
  0x00, 0x00, 0xFF, 0x00, 0xFF, 0x00, 0x00, 0x00, 0xFF, 0x0C, \
0xF4, 0xD5, 0x4B, 0x01, 0x01, 0x00, 0x04, 0x08, 0x04, 0x00, 0x00, 0x00, 0x00, 0x4b, 0x00};
unsigned char old_id[5];

unsigned char receive_ACK[25];//Command receiving buffer
//int inByte = 0;               //incoming serial byte buffer

#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#define print1Byte(args) Serial1.write(args)
#define print1lnByte(args)  Serial1.write(args),Serial1.println()
#else
#include "WProgram.h"
#define print1Byte(args) Serial1.print(args,BYTE)
#define print1lnByte(args)  Serial1.println(args,BYTE)
#endif

void setup(){
  Serial.begin(9600);   // open serial with PC
  Serial1.begin(115200);    //open serial1 with device
  //Serial2.begin(115200);
  wake_card();
  delay(100);
  read_ACK(15);
  delay(100);
  display(15);
}

void loop(){
  send_tag();
  read_ACK(25);
  delay(100);
  if (!cmp_id ()) {
    if (test_ACK ()) {
      display (25);
      delay (100);
    }
  }
  copy_id ();
}

void copy_id (void) {//save old id
  int ai, oi;
  for (oi=0, ai=19; oi<5; oi++,ai++) {
    old_id[oi] = receive_ACK[ai];
  }
}

char cmp_id (void){//return true if find id is old
  int ai, oi;
  for (oi=0,ai=19; oi<5; oi++,ai++) {
    if (old_id[oi] != receive_ACK[ai])
      return 0;
  }
  return 1;
}

int test_ACK (void) {// return true if receive_ACK accord with std_ACK
  int i;
  for (i=0; i<19; i++) {
    if (receive_ACK[i] != std_ACK[i])
      return 0;
  }
  return 1;
}

void send_id (void) {//send id to PC
  int i;
  Serial.print ("ID: ");
  for (i=19; i<= 23; i++) {
    Serial.print (receive_ACK[i], HEX);
    Serial.print (" ");
  }
  Serial.println ();
}

void UART1_Send_Byte(unsigned char command_data){//send byte to device
  print1Byte(command_data);
#if defined(ARDUINO) && ARDUINO >= 100
  Serial1.flush();// complete the transmission of outgoing serial data
#endif
}

void UART_Send_Byte(unsigned char command_data){//send byte to PC
  Serial.print(command_data,HEX);
  Serial.print(" ");
}

void read_ACK(unsigned char temp){//read ACK into reveive_ACK[]
  unsigned char i;
  for(i=0;i<temp;i++) {
    receive_ACK[i]= Serial1.read();
  }
}

void wake_card(void){//send wake[] to device
  unsigned char i;
  for(i=0;i<24;i++) //send command
    UART1_Send_Byte(wake[i]);
}

void firmware_version(void){//send fireware[] to device
  unsigned char i;
  for(i=0;i<9;i++) //send command
    UART1_Send_Byte(firmware[i]);
}

void send_tag(void){//send tag[] to device
  unsigned char i;
  for(i=0;i<11;i++) //send command
    UART1_Send_Byte(tag[i]);
}

void display(unsigned char tem){//send receive_ACK[] to PC
  unsigned char i;
  for(i=0;i<tem;i++) //send command
    UART_Send_Byte(receive_ACK[i]);
  Serial.println();
}