嵌入式

//******************************************************************/
//功    能：寻卡                                                    /
//参数说明: req_code[IN]:寻卡方式                                      /
//                0x52 = 寻感应区内所有符合14443A标准的卡          /
//                0x26 = 寻未进入休眠状态的卡                       /
//          pTagType[OUT]：卡片类型代码                             /
//                0x4400 = Mifare_UltraLight                           /
//                0x0400 = Mifare_One(S50)                            /
//                0x0200 = Mifare_One(S70)                            /
//                0x0800 = Mifare_Pro(X)                              /
//                0x4403 = Mifare_DESFire                             /
//返    回: 成功返回MI_OK                                          /
//******************************************************************/
char PcdRequest(unsigned char req_code,unsigned char *pTagType)
{
  char status                                        ;  
  unsigned int  unLen                                ;
  unsigned char ucComMF522Buf[MAXRLEN]           ; 

  ClearBitMask(Status2Reg,0x08)                      ;
  WriteRawRC(BitFramingReg,0x07)                   ;
  SetBitMask(TxControlReg,0x03)                     ;
 
  ucComMF522Buf[0] = req_code                        ;

  status = PcdComMF522(PCD_TRANSCEIVE,ucComMF522Buf,
                       1,ucComMF522Buf,&unLen       );
  if ((status == MI_OK) && (unLen == 0x10))
  {    
    *pTagType     = ucComMF522Buf[0]                 ;
    *(pTagType+1) = ucComMF522Buf[1]                 ;
  }
  else
    status = MI_ERR                                  ;
  return status                                      ;
}     

//******************************************************************/
//功    能：防冲撞                                                  /
//参数说明: pSnr[OUT]:卡片序列号，4字节                              /
//返    回: 成功返回MI_OK                                          /
//******************************************************************/

char PcdAnticoll(unsigned char *pSnr)
{
    char status;
    unsigned char i,snr_check=0;
    unsigned int  unLen;
    unsigned char ucComMF522Buf[MAXRLEN]; 
    
    ClearBitMask(Status2Reg,0x08);
    WriteRawRC(BitFramingReg,0x00);
    ClearBitMask(CollReg,0x80);
 
    ucComMF522Buf[0] = PICC_ANTICOLL1;
    ucComMF522Buf[1] = 0x20;
   Status=PcdComMF522(PCD_TRANSCEIVE,ucComMF522Buf,2,ucComMF522Buf,&unLen);

    if (status == MI_OK)
    {
    	 for (i=0; i<4; i++)
         {   
             *(pSnr+i)  = ucComMF522Buf[i];
             snr_check ^= ucComMF522Buf[i];
         }
         if (snr_check != ucComMF522Buf[i])
         {   status = MI_ERR;    }
    }
    
    SetBitMask(CollReg,0x80);
    return status;
}