How to connect an NFC reader to Arduino

/** include library */ 
#include "Wire.h" 
#include "nfc.h" 
/** define an nfc object 
*/
NFC_Module nfc; 
void setup(void) 
{ 
Serial.begin(9600); 
nfc.begin(); 
Serial.println("MF1S50 Reader Demo From Elechouse!"); 
uint32_t versiondata = nfc.get_version(); 
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 normal mode, and disable SAM */ 
nfc.SAMConfiguration(); 
} 
void loop(void) 
{ 
u8 buf[32],sta; 
/** Polling the mifar card, buf[0] is the length of the UID */ 
sta = nfc.InListPassiveTarget(buf); 
/** check state and UID length */
if(sta && buf[0] == 4){ 
/** the card may be Mifare Classic card, try to read the block */ 
Serial.print("UUID length:"); 
Serial.print(buf[0], DEC); 
Serial.println(); 
Serial.print("UUID:"); 
nfc.puthex(buf+1, buf[0]); 
// print out the UID 
Serial.println(); 
/** factory default KeyA: 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF */
u8 key[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; 
u8 blocknum = 4; 
/** Authentication block 4 */ 
sta = nfc.MifareAuthentication(0, blocknum, buf+1, buf[0], key); 
if(sta){ 
/** create array to save block data read from the card
*/
u8 block[16]; 
Serial.println("Authentication success."); 
/*********************************************************** 
The following are examples to write data to RFID card. To 
protect user
’
s data in RFID card. By Default we disabled it. 
Please remove the annotation symbol to enable it 
***********************************************************/ 
/* 
strcpy((char*)block, "Elechou
se
- NFC"); 
sta = nfc.MifareWriteBlock(blocknum, block); 
if(sta){ 
Serial.println("Write block successfully:"); 
} 
*/ 
/*********************************************************** 
The following are examples to read data from RFID card. 
***********************************************************/
/** read block 4 */ 
sta = nfc.MifareReadBlock(blocknum, block); 
if(sta){ 
Serial.println("Read block successfully:"); 
nfc.puthex(block, 16); 
Serial.println(); 
} 
/** read block 5 */
sta = nfc.MifareReadBlock(blocknum+1, block); 
if(sta){ 
Serial.println("Read block successfully:"); 
nfc.puthex(block, 16); 
Serial.println(); 
} 
/** read block 6 */ 
sta = nfc.MifareReadBlock(blocknum+2, block); 
if(sta){ 
Serial.println("Read block successfully:"); 
nfc.puthex(block, 16); 
Serial.println(); 
} 
/** read block 7 */ 
sta = nfc.MifareReadBlock(blocknum+3, block); 
if(sta){ 
Serial.println("Read block successfully:"); 
nfc.puthex(block, 16); 
Serial.println(); 
} 
} 
} 
}