Arduino中MFRC-522射频IC卡感应模块使用

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我是靠谱客的博主炙热心锁，最近开发中收集的这篇文章主要介绍Arduino中MFRC-522射频IC卡感应模块使用，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

连接图和 http://blog.csdn.net/zitech/article/details/24130405 中的一样

在这次试验中，我们会进行写与读两种操作，全部代码如下：

#include <SPI.h>
#include <RFID.h>

RFID rfid(10,5);    //D10--读卡器MOSI引脚、D5--读卡器RST引脚

//4字节卡序列号，第5字节为校验字节
unsigned char serNum[5];
//写卡数据
unsigned char writeDate[16] ={'G', 'e', 'e', 'k', '-', 'W', 'o', 'r', 'k', 'S', 'h', 'o', 'p', 0, 0, 0};
//原扇区A密码，16个扇区，每个扇区密码6Byte
unsigned char sectorKeyA[16][16] = {
        {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
        {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
        {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},};
//新扇区A密码，16个扇区，每个扇区密码6Byte
unsigned char sectorNewKeyA[16][16] = {
        {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
        {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xff,0x07,0x80,0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
        {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xff,0x07,0x80,0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},};

void setup()
{
  Serial.begin(9600);
  SPI.begin();
  rfid.init();
}

void loop()
{
  unsigned char i,tmp;
  unsigned char status;
  unsigned char str[MAX_LEN];
  unsigned char RC_size;
  unsigned char blockAddr;        //选择操作的块地址0～63

  //找卡
  rfid.isCard();
  //读取卡序列号
  if (rfid.readCardSerial())
  {
    Serial.print("The card's number is  : ");
    Serial.print(rfid.serNum[0],HEX);
    Serial.print(rfid.serNum[1],HEX);
    Serial.print(rfid.serNum[2],HEX);
    Serial.print(rfid.serNum[3],HEX);
    Serial.print(rfid.serNum[4],HEX);
    Serial.println(" ");
  }

  //选卡，返回卡容量（锁定卡片，防止多次读写）
  rfid.selectTag(rfid.serNum);
  
  //写数据卡
  blockAddr = 7;                //数据块7
  if (rfid.auth(PICC_AUTHENT1A, blockAddr, sectorKeyA[blockAddr/4], rfid.serNum) == MI_OK)  //认证
  {
    //写数据
    status = rfid.write(blockAddr, sectorNewKeyA[blockAddr/4]);
    Serial.print("set the new card password, and can modify the data of the Sector: ");
    Serial.println(blockAddr/4,DEC);
    //写数据
    blockAddr = blockAddr - 3 ; //数据块4
    status = rfid.write(blockAddr, writeDate);
    if(status == MI_OK)
    {
      Serial.println("Write card OK!");
    }
  }

  //读卡
  blockAddr = 7;                //数据块7
  status = rfid.auth(PICC_AUTHENT1A, blockAddr, sectorNewKeyA[blockAddr/4], rfid.serNum);
  if (status == MI_OK)  //认证
  {
    //读数据
    blockAddr = blockAddr - 3 ; //数据块4
    if( rfid.read(blockAddr, str) == MI_OK)
    {
      Serial.print("Read from the card ,the data is : ");
      Serial.println((char *)str);
    }
  }
  
  rfid.halt();
}

在这里我们写了一个专门用于 Arduino中MFRC-522射频IC卡感应模块使用的RC522库文件。

#include <RFID.h>

所有代码（库文件）下载： RFID_MFRC522库文件

库文件见：

#ifndef RFID_h
#define RFID_h

#include <Arduino.h>
#include <SPI.h>


/******************************************************************************
 * 定义
 ******************************************************************************/
#define MAX_LEN 16   // 数组最大长度

//MF522命令字
#define PCD_IDLE              0x00               //无动作，取消当前命令
#define PCD_AUTHENT           0x0E               //验证密钥
#define PCD_RECEIVE           0x08               //接收数据
#define PCD_TRANSMIT          0x04               //发送数据
#define PCD_TRANSCEIVE        0x0C               //发送并接收数据
#define PCD_RESETPHASE        0x0F               //复位
#define PCD_CALCCRC           0x03               //CRC计算

//Mifare_One卡片命令字
#define PICC_REQIDL           0x26               //寻天线区内未进入休眠状态
#define PICC_REQALL           0x52               //寻天线区内全部卡
#define PICC_ANTICOLL         0x93               //防冲撞
#define PICC_SElECTTAG        0x93               //选卡
#define PICC_AUTHENT1A        0x60               //验证A密钥
#define PICC_AUTHENT1B        0x61               //验证B密钥
#define PICC_READ             0x30               //读块
#define PICC_WRITE            0xA0               //写块
#define PICC_DECREMENT        0xC0               
#define PICC_INCREMENT        0xC1               
#define PICC_RESTORE          0xC2               //调块数据到缓冲区
#define PICC_TRANSFER         0xB0               //保存缓冲区中数据
#define PICC_HALT             0x50               //休眠
 
//和MF522通讯时返回的错误代码
#define MI_OK                 0
#define MI_NOTAGERR           1
#define MI_ERR                2


//------------------MFRC522寄存器---------------
//Page 0:Command and Status
#define     Reserved00            0x00    
#define     CommandReg            0x01    
#define     CommIEnReg            0x02    
#define     DivlEnReg             0x03    
#define     CommIrqReg            0x04    
#define     DivIrqReg             0x05
#define     ErrorReg              0x06    
#define     Status1Reg            0x07    
#define     Status2Reg            0x08    
#define     FIFODataReg           0x09
#define     FIFOLevelReg          0x0A
#define     WaterLevelReg         0x0B
#define     ControlReg            0x0C
#define     BitFramingReg         0x0D
#define     CollReg               0x0E
#define     Reserved01            0x0F
//Page 1:Command     
#define     Reserved10            0x10
#define     ModeReg               0x11
#define     TxModeReg             0x12
#define     RxModeReg             0x13
#define     TxControlReg          0x14
#define     TxAutoReg             0x15
#define     TxSelReg              0x16
#define     RxSelReg              0x17
#define     RxThresholdReg        0x18
#define     DemodReg              0x19
#define     Reserved11            0x1A
#define     Reserved12            0x1B
#define     MifareReg             0x1C
#define     Reserved13            0x1D
#define     Reserved14            0x1E
#define     SerialSpeedReg        0x1F
//Page 2:CFG    
#define     Reserved20            0x20  
#define     CRCResultRegM         0x21
#define     CRCResultRegL         0x22
#define     Reserved21            0x23
#define     ModWidthReg           0x24
#define     Reserved22            0x25
#define     RFCfgReg              0x26
#define     GsNReg                0x27
#define     CWGsPReg              0x28
#define     ModGsPReg             0x29
#define     TModeReg              0x2A
#define     TPrescalerReg         0x2B
#define     TReloadRegH           0x2C
#define     TReloadRegL           0x2D
#define     TCounterValueRegH     0x2E
#define     TCounterValueRegL     0x2F
//Page 3:TestRegister     
#define     Reserved30            0x30
#define     TestSel1Reg           0x31
#define     TestSel2Reg           0x32
#define     TestPinEnReg          0x33
#define     TestPinValueReg       0x34
#define     TestBusReg            0x35
#define     AutoTestReg           0x36
#define     VersionReg            0x37
#define     AnalogTestReg         0x38
#define     TestDAC1Reg           0x39  
#define     TestDAC2Reg           0x3A   
#define     TestADCReg            0x3B   
#define     Reserved31            0x3C   
#define     Reserved32            0x3D   
#define     Reserved33            0x3E   
#define     Reserved34            0x3F
//-----------------------------------------------

class RFID
{
  public:
	RFID(int chipSelectPin, int NRSTPD);  //读卡器MOSI引脚、读卡器RST引脚

	bool isCard();
	bool readCardSerial();
	void init();
	void reset();
	void setBitMask(unsigned char reg, unsigned char mask);
	void clearBitMask(unsigned char reg, unsigned char mask);
	void antennaOn(void);
	void antennaOff(void);
	void calculateCRC(unsigned char *pIndata, unsigned char len, unsigned char *pOutData);
	void writeMFRC522(unsigned char addr, unsigned char val);
	unsigned char readMFRC522(unsigned char addr);
	unsigned char MFRC522Request(unsigned char reqMode, unsigned char *TagType);
	unsigned char MFRC522ToCard(unsigned char command, unsigned char *sendData, unsigned char sendLen, unsigned char *backData, unsigned int *backLen);
	unsigned char anticoll(unsigned char *serNum);
	unsigned char auth(unsigned char authMode, unsigned char BlockAddr, unsigned char *Sectorkey, unsigned char *serNum);
	unsigned char read(unsigned char blockAddr, unsigned char *recvData);
	unsigned char write(unsigned char blockAddr, unsigned char *writeData);
	unsigned char selectTag(unsigned char *serNum);
	void halt();
	
	unsigned char serNum[5];       // 4字节卡序列号，第5字节为校验字节
	
  private:
	int _chipSelectPin;
	int _NRSTPD;
};

#endif

头文件中函数的实现是在一个名为 RFID.cpp 的文件中，具体为：

******************************************************************************
 * 包含文件
 ******************************************************************************/
#include <Arduino.h>
#include <RFID.h>

/******************************************************************************
 * 构造 RFID
 * int chipSelectPin RFID /ENABLE pin
 ******************************************************************************/
RFID::RFID(int chipSelectPin, int NRSTPD)
{
  _chipSelectPin = chipSelectPin;
  _NRSTPD = NRSTPD;

  pinMode(_chipSelectPin,OUTPUT);     // 设置管脚_chipSelectPin为输出并连接到模块使能口
  digitalWrite(_chipSelectPin, LOW);


  pinMode(_NRSTPD,OUTPUT);            // 设置管脚NRSTPD为输出，非重置或掉电
  digitalWrite(_NRSTPD, HIGH);
}

/******************************************************************************
 * 用户 API
 ******************************************************************************/

/******************************************************************************
 * 函 数 名：isCard
 * 功能描述：寻卡
 * 输入参数：无
 * 返 回 值：成功返回ture 失败返回false
 ******************************************************************************/
bool RFID::isCard()
{
  unsigned char status;
  unsigned char str[MAX_LEN];

  status = MFRC522Request(PICC_REQIDL, str);
  if (status == MI_OK)
    return true;
  else
    return false;
}

/******************************************************************************
 * 函 数 名：readCardSerial
 * 功能描述：返回卡的序列号 4字节
 * 输入参数：无
 * 返 回 值：成功返回ture 失败返回false
 ******************************************************************************/
bool RFID::readCardSerial(){

  unsigned char status;
  unsigned char str[MAX_LEN];
  
  // 防冲撞，返回卡的序列号 4字节，存入serNum中
  status = anticoll(str);
  memcpy(serNum, str, 5);
  
  if (status == MI_OK)
    return true;
  else
    return false;
}

/******************************************************************************
 * 函 数 名：init
 * 功能描述：初始化RC522
 * 输入参数：无
 * 返 回 值：无
 ******************************************************************************/
void RFID::init()
{
  digitalWrite(_NRSTPD,HIGH);

  reset();

  //Timer: TPrescaler*TreloadVal/6.78MHz = 24ms
  writeMFRC522(TModeReg, 0x8D);   //Tauto=1; f(Timer) = 6.78MHz/TPreScaler
  writeMFRC522(TPrescalerReg, 0x3E);  //TModeReg[3..0] + TPrescalerReg
  writeMFRC522(TReloadRegL, 30);
  writeMFRC522(TReloadRegH, 0);
  writeMFRC522(TxAutoReg, 0x40);    //100%ASK
  writeMFRC522(ModeReg, 0x3D);    // CRC valor inicial de 0x6363

  //ClearBitMask(Status2Reg, 0x08); //MFCrypto1On=0
  //writeMFRC522(RxSelReg, 0x86);   //RxWait = RxSelReg[5..0]
  //writeMFRC522(RFCfgReg, 0x7F);     //RxGain = 48dB

  antennaOn();    //打开天线
}

/******************************************************************************
 * 函 数 名：reset
 * 功能描述：复位RC522
 * 输入参数：无
 * 返 回 值：无
 ******************************************************************************/
void RFID::reset()
{
  writeMFRC522(CommandReg, PCD_RESETPHASE);
}

/******************************************************************************
 * 函 数 名：writeMFRC522
 * 功能描述：向MFRC522的某一寄存器写一个字节数据
 * 输入参数：addr--寄存器地址；val--要写入的值
 * 返 回 值：无
 ******************************************************************************/
void RFID::writeMFRC522(unsigned char addr, unsigned char val)
{
  digitalWrite(_chipSelectPin, LOW);

  //地址格式：0XXXXXX0
  SPI.transfer((addr<<1)&0x7E);
  SPI.transfer(val);

  digitalWrite(_chipSelectPin, HIGH);
}

/******************************************************************************
 * 函 数 名：readMFRC522
 * 功能描述：从MFRC522的某一寄存器读一个字节数据
 * 输入参数：addr--寄存器地址
 * 返 回 值：返回读取到的一个字节数据
 ******************************************************************************/
unsigned char RFID::readMFRC522(unsigned char addr)
{
  unsigned char val;
  digitalWrite(_chipSelectPin, LOW);
  SPI.transfer(((addr<<1)&0x7E) | 0x80);
  val =SPI.transfer(0x00);
  digitalWrite(_chipSelectPin, HIGH);
  return val;
}

/******************************************************************************
 * 函 数 名：setBitMask
 * 功能描述：置RC522寄存器位
 * 输入参数：reg--寄存器地址;mask--置位值
 * 返 回 值：无
 ******************************************************************************/
void RFID::setBitMask(unsigned char reg, unsigned char mask)
{
  unsigned char tmp;
  tmp = readMFRC522(reg);
  writeMFRC522(reg, tmp | mask);  // set bit mask
}

/******************************************************************************
 * 函 数 名：clearBitMask
 * 功能描述：清RC522寄存器位
 * 输入参数：reg--寄存器地址;mask--清位值
 * 返 回 值：无
 ******************************************************************************/
void RFID::clearBitMask(unsigned char reg, unsigned char mask)
{
  unsigned char tmp;
  tmp = readMFRC522(reg);
  writeMFRC522(reg, tmp & (~mask));  // clear bit mask
}

/******************************************************************************
 * 函 数 名：antennaOn
 * 功能描述：开启天线,每次启动或关闭天险发射之间应至少有1ms的间隔
 * 输入参数：无
 * 返 回 值：无
 ******************************************************************************/
void RFID::antennaOn(void)
{
  unsigned char temp;

  temp = readMFRC522(TxControlReg);
  if (!(temp & 0x03))
  {
    setBitMask(TxControlReg, 0x03);
  }
}

/******************************************************************************
 * 函 数 名：antennaOff
 * 功能描述：关闭天线,每次启动或关闭天险发射之间应至少有1ms的间隔
 * 输入参数：无
 * 返 回 值：无
 ******************************************************************************/
void RFID::antennaOff(void)
{
  unsigned char temp;

  temp = readMFRC522(TxControlReg);
  if (!(temp & 0x03))
  {
    clearBitMask(TxControlReg, 0x03);
  }
}

/******************************************************************************
 * 函 数 名：calculateCRC
 * 功能描述：用MF522计算CRC
 * 输入参数：pIndata--要读数CRC的数据，len--数据长度，pOutData--计算的CRC结果
 * 返 回 值：无
 ******************************************************************************/
void RFID::calculateCRC(unsigned char *pIndata, unsigned char len, unsigned char *pOutData)
{
  unsigned char i, n;

  clearBitMask(DivIrqReg, 0x04);      //CRCIrq = 0
  setBitMask(FIFOLevelReg, 0x80);     //清FIFO指针
  //Write_MFRC522(CommandReg, PCD_IDLE);

  //向FIFO中写入数据
  for (i=0; i<len; i++)
    writeMFRC522(FIFODataReg, *(pIndata+i));
  writeMFRC522(CommandReg, PCD_CALCCRC);

  //等待CRC计算完成
  i = 0xFF;
  do
  {
    n = readMFRC522(DivIrqReg);
    i--;
  }
  while ((i!=0) && !(n&0x04));      //CRCIrq = 1

  //读取CRC计算结果
  pOutData[0] = readMFRC522(CRCResultRegL);
  pOutData[1] = readMFRC522(CRCResultRegM);
}

/******************************************************************************
 * 函 数 名：MFRC522ToCard
 * 功能描述：RC522和ISO14443卡通讯
 * 输入参数：command--MF522命令字，
 *           sendData--通过RC522发送到卡片的数据,
 *                     sendLen--发送的数据长度
 *                     backData--接收到的卡片返回数据，
 *                     backLen--返回数据的位长度
 * 返 回 值：成功返回MI_OK
 ******************************************************************************/
unsigned char RFID::MFRC522ToCard(unsigned char command, unsigned char *sendData, unsigned char sendLen, unsigned char *backData, unsigned int *backLen)
{
  unsigned char status = MI_ERR;
  unsigned char irqEn = 0x00;
  unsigned char waitIRq = 0x00;
  unsigned char lastBits;
  unsigned char n;
  unsigned int i;

  switch (command)
  {
    case PCD_AUTHENT:   //认证卡密
    {
      irqEn = 0x12;
      waitIRq = 0x10;
      break;
    }
    case PCD_TRANSCEIVE:  //发送FIFO中数据
    {
      irqEn = 0x77;
      waitIRq = 0x30;
      break;
    }
    default:
      break;
  }

  writeMFRC522(CommIEnReg, irqEn|0x80); //允许中断请求
  clearBitMask(CommIrqReg, 0x80);       //清除所有中断请求位
  setBitMask(FIFOLevelReg, 0x80);       //FlushBuffer=1, FIFO初始化

  writeMFRC522(CommandReg, PCD_IDLE);   //无动作，取消当前命令

  //向FIFO中写入数据
  for (i=0; i<sendLen; i++)
    writeMFRC522(FIFODataReg, sendData[i]);

  //执行命令
  writeMFRC522(CommandReg, command);
  if (command == PCD_TRANSCEIVE)
    setBitMask(BitFramingReg, 0x80);    //StartSend=1,transmission of data starts

  //等待接收数据完成
  i = 2000; //i根据时钟频率调整，操作M1卡最大等待时间25ms
  do
  {
    //CommIrqReg[7..0]
    //Set1 TxIRq RxIRq IdleIRq HiAlerIRq LoAlertIRq ErrIRq TimerIRq
    n = readMFRC522(CommIrqReg);
    i--;
  }
  while ((i!=0) && !(n&0x01) && !(n&waitIRq));

  clearBitMask(BitFramingReg, 0x80);      //StartSend=0

  if (i != 0)
  {
    if(!(readMFRC522(ErrorReg) & 0x1B)) //BufferOvfl Collerr CRCErr ProtecolErr
    {
      status = MI_OK;
      if (n & irqEn & 0x01)
        status = MI_NOTAGERR;     //??

      if (command == PCD_TRANSCEIVE)
      {
        n = readMFRC522(FIFOLevelReg);
        lastBits = readMFRC522(ControlReg) & 0x07;
        if (lastBits)
          *backLen = (n-1)*8 + lastBits;
        else
          *backLen = n*8;

        if (n == 0)
          n = 1;
        if (n > MAX_LEN)
          n = MAX_LEN;

        //读取FIFO中接收到的数据
        for (i=0; i<n; i++)
          backData[i] = readMFRC522(FIFODataReg);
      }
    }
    else
      status = MI_ERR;
  }

  //SetBitMask(ControlReg,0x80);           //timer stops
  //Write_MFRC522(CommandReg, PCD_IDLE);

  return status;
}


/******************************************************************************
 * 函 数 名：MFRC522Request
 * 功能描述：寻卡，读取卡类型号
 * 输入参数：reqMode--寻卡方式，
 *           TagType--返回卡片类型
 *                    0x4400 = Mifare_UltraLight
 *                    0x0400 = Mifare_One(S50)
 *                    0x0200 = Mifare_One(S70)
 *                    0x0800 = Mifare_Pro(X)
 *                    0x4403 = Mifare_DESFire
 * 返 回 值：成功返回MI_OK
 ******************************************************************************/
unsigned char RFID::MFRC522Request(unsigned char reqMode, unsigned char *TagType)
{
  unsigned char status;
  unsigned int backBits;      //接收到的数据位数

  writeMFRC522(BitFramingReg, 0x07);    //TxLastBists = BitFramingReg[2..0] ???

  TagType[0] = reqMode;
  status = MFRC522ToCard(PCD_TRANSCEIVE, TagType, 1, TagType, &backBits);

  if ((status != MI_OK) || (backBits != 0x10))
    status = MI_ERR;

  return status;
}

/******************************************************************************
 * 函 数 名：anticoll
 * 功能描述：防冲突检测，读取选中卡片的卡序列号
 * 输入参数：serNum--返回4字节卡序列号,第5字节为校验字节
 * 返 回 值：成功返回MI_OK
 ******************************************************************************/
unsigned char RFID::anticoll(unsigned char *serNum)
{
  unsigned char status;
  unsigned char i;
  unsigned char serNumCheck=0;
  unsigned int unLen;

  //ClearBitMask(Status2Reg, 0x08);   //TempSensclear
  //ClearBitMask(CollReg,0x80);     //ValuesAfterColl
  writeMFRC522(BitFramingReg, 0x00);    //TxLastBists = BitFramingReg[2..0]

  serNum[0] = PICC_ANTICOLL;
  serNum[1] = 0x20;
  status = MFRC522ToCard(PCD_TRANSCEIVE, serNum, 2, serNum, &unLen);

  if (status == MI_OK)
  {
    //校验卡序列号
    for (i=0; i<4; i++)
      serNumCheck ^= serNum[i];
    if (serNumCheck != serNum[i])
      status = MI_ERR;
  }

  //SetBitMask(CollReg, 0x80);    //ValuesAfterColl=1

  return status;
}

/******************************************************************************
 * 函 数 名：auth
 * 功能描述：验证卡片密码
 * 输入参数：authMode--密码验证模式
 *                     0x60 = 验证A密钥
 *                     0x61 = 验证B密钥
 *           BlockAddr--块地址
 *           Sectorkey--扇区密码
 *           serNum--卡片序列号，4字节
 * 返 回 值：成功返回MI_OK
 ******************************************************************************/
unsigned char RFID::auth(unsigned char authMode, unsigned char BlockAddr, unsigned char *Sectorkey, unsigned char *serNum)
{
  unsigned char status;
  unsigned int recvBits;
  unsigned char i;
  unsigned char buff[12];

  //验证指令+块地址＋扇区密码＋卡序列号
  buff[0] = authMode;
  buff[1] = BlockAddr;
  for (i=0; i<6; i++)
    buff[i+2] = *(Sectorkey+i);
  for (i=0; i<4; i++)
    buff[i+8] = *(serNum+i);
    
  status = MFRC522ToCard(PCD_AUTHENT, buff, 12, buff, &recvBits);
  if ((status != MI_OK) || (!(readMFRC522(Status2Reg) & 0x08)))
    status = MI_ERR;

  return status;
}

/******************************************************************************
 * 函 数 名：read
 * 功能描述：读块数据
 * 输入参数：blockAddr--块地址;recvData--读出的块数据
 * 返 回 值：成功返回MI_OK
 ******************************************************************************/
unsigned char RFID::read(unsigned char blockAddr, unsigned char *recvData)
{
  unsigned char status;
  unsigned int unLen;

  recvData[0] = PICC_READ;
  recvData[1] = blockAddr;
  calculateCRC(recvData,2, &recvData[2]);
  status = MFRC522ToCard(PCD_TRANSCEIVE, recvData, 4, recvData, &unLen);

  if ((status != MI_OK) || (unLen != 0x90))
    status = MI_ERR;

  return status;
}

/******************************************************************************
 * 函 数 名：write
 * 功能描述：写块数据
 * 输入参数：blockAddr--块地址;writeData--向块写16字节数据
 * 返 回 值：成功返回MI_OK
 ******************************************************************************/
unsigned char RFID::write(unsigned char blockAddr, unsigned char *writeData)
{
  unsigned char status;
  unsigned int recvBits;
  unsigned char i;
  unsigned char buff[18];

  buff[0] = PICC_WRITE;
  buff[1] = blockAddr;
  calculateCRC(buff, 2, &buff[2]);
  status = MFRC522ToCard(PCD_TRANSCEIVE, buff, 4, buff, &recvBits);

  if ((status != MI_OK) || (recvBits != 4) || ((buff[0] & 0x0F) != 0x0A))
    status = MI_ERR;

  if (status == MI_OK)
  {
    for (i=0; i<16; i++)    //?FIFO?16Byte?? Datos a la FIFO 16Byte escribir
      buff[i] = *(writeData+i);
      
    calculateCRC(buff, 16, &buff[16]);
    status = MFRC522ToCard(PCD_TRANSCEIVE, buff, 18, buff, &recvBits);

    if ((status != MI_OK) || (recvBits != 4) || ((buff[0] & 0x0F) != 0x0A))
      status = MI_ERR;
  }

  return status;
}

/******************************************************************************
 * 函 数 名：selectTag
 * 功能描述：选卡，读取卡存储器容量
 * 输入参数：serNum--传入卡序列号
 * 返 回 值：成功返回卡容量
 ******************************************************************************/
unsigned char RFID::selectTag(unsigned char *serNum)
{
  unsigned char i;
  unsigned char status;
  unsigned char size;
  unsigned int recvBits;
  unsigned char buffer[9];

  //ClearBitMask(Status2Reg, 0x08);                        //MFCrypto1On=0

  buffer[0] = PICC_SElECTTAG;
  buffer[1] = 0x70;

  for (i=0; i<5; i++)
    buffer[i+2] = *(serNum+i);

  calculateCRC(buffer, 7, &buffer[7]);
  
  status = MFRC522ToCard(PCD_TRANSCEIVE, buffer, 9, buffer, &recvBits);
  if ((status == MI_OK) && (recvBits == 0x18))
    size = buffer[0];
  else
    size = 0;
  return size;
}

/******************************************************************************
 * 函 数 名：Halt
 * 功能描述：命令卡片进入休眠状态
 * 输入参数：无
 * 返 回 值：无
 ******************************************************************************/
void RFID::halt()
{
  unsigned char status;
  unsigned int unLen;
  unsigned char buff[4];

  buff[0] = PICC_HALT;
  buff[1] = 0;
  calculateCRC(buff, 2, &buff[2]);

  status = MFRC522ToCard(PCD_TRANSCEIVE, buff, 4, buff,&unLen);
}

所有代码（库文件）下载： RFID_MFRC522库文件