/*
* Function?MFRC522_Request
* Description?Searching card, read card type
* Input parameter?reqMode--search methods?
* TagType--return card types
* 0x4400 = Mifare_UltraLight
* 0x0400 = Mifare_One(S50)
* 0x0200 = Mifare_One(S70)
* 0x0800 = Mifare_Pro(X)
* 0x4403 = Mifare_DESFire
* return?return MI_OK if successed
*/
uchar MFRC522_Request(uchar reqMode, uchar *TagType)
{
uchar status;
uint backBits; //the data bits that received
Write_MFRC522(BitFramingReg, 0x07); //TxLastBists = BitFramingReg[2..0] ???
TagType[0] = reqMode;
status = MFRC522_ToCard(PCD_TRANSCEIVE, TagType, 1, TagType, &backBits);
if ((status != MI_OK) || (backBits != 0x10))
{
status = MI_ERR;
}
return status;
}
/*
* Function?MFRC522_ToCard
* Description?communicate between RC522 and ISO14443
* Input parameter?command--MF522 command bits
* sendData--send data to card via rc522
* sendLen--send data length
* backData--the return data from card
* backLen--the length of return data
* return?return MI_OK if successed
*/
uchar MFRC522_ToCard(uchar command, uchar *sendData, uchar sendLen, uchar *backData, uint *backLen)
{
uchar status = MI_ERR;
uchar irqEn = 0x00;
uchar waitIRq = 0x00;
uchar lastBits;
uchar n;
uint i;
switch (command)
{
case PCD_AUTHENT: //verify card password
{
irqEn = 0x12;
waitIRq = 0x10;
break;
}
case PCD_TRANSCEIVE: //send data in the FIFO
{
irqEn = 0x77;
waitIRq = 0x30;
break;
}
default:
break;
}
Write_MFRC522(CommIEnReg, irqEn|0x80); //Allow interruption
ClearBitMask(CommIrqReg, 0x80); //Clear all the interrupt bits
SetBitMask(FIFOLevelReg, 0x80); //FlushBuffer=1, FIFO initilizate
Write_MFRC522(CommandReg, PCD_IDLE); //NO action;cancel current command ???
//write data into FIFO
for (i=0; i<sendLen; i++)
{
Write_MFRC522(FIFODataReg, sendData[i]);
}
//procceed it
Write_MFRC522(CommandReg, command);
if (command == PCD_TRANSCEIVE)
{
SetBitMask(BitFramingReg, 0x80); //StartSend=1,transmission of data starts
}
//waite receive data is finished
i = 2000; //i should adjust according the clock, the maxium the waiting time should be 25 ms???
do
{
//CommIrqReg[7..0]
//Set1 TxIRq RxIRq IdleIRq HiAlerIRq LoAlertIRq ErrIRq TimerIRq
n = Read_MFRC522(CommIrqReg);
i--;
}
while ((i!=0) && !(n&0x01) && !(n&waitIRq));
ClearBitMask(BitFramingReg, 0x80); //StartSend=0
if (i != 0)
{
if(!(Read_MFRC522(ErrorReg) & 0x1B)) //BufferOvfl Collerr CRCErr ProtecolErr
{
status = MI_OK;
if (n & irqEn & 0x01)
{
status = MI_NOTAGERR; //??
}
if (command == PCD_TRANSCEIVE)
{
n = Read_MFRC522(FIFOLevelReg);
lastBits = Read_MFRC522(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;
}
//read the data from FIFO
for (i=0; i<n; i++)
{
backData[i] = Read_MFRC522(FIFODataReg);
}
}
}
else
{
status = MI_ERR;
}
}
//SetBitMask(ControlReg,0x80); //timer stops
//Write_MFRC522(CommandReg, PCD_IDLE);
return status;
}
/*
* Function?MFRC522_Anticoll
* Description?Prevent conflict, read the card serial number
* Input parameter?serNum--return the 4 bytes card serial number, the 5th byte is recheck byte
* return?return MI_OK if successed
*/
uchar MFRC522_Anticoll(uchar *serNum)
{
uchar status;
uchar i;
uchar serNumCheck=0;
uint unLen;
//ClearBitMask(Status2Reg, 0x08); //strSensclear
//ClearBitMask(CollReg,0x80); //ValuesAfterColl
Write_MFRC522(BitFramingReg, 0x00); //TxLastBists = BitFramingReg[2..0]
serNum[0] = PICC_ANTICOLL;
serNum[1] = 0x20;
status = MFRC522_ToCard(PCD_TRANSCEIVE, serNum, 2, serNum, &unLen);
if (status == MI_OK)
{
//Verify card serial number
for (i=0; i<4; i++)
{
serNumCheck ^= serNum[i];
}
if (serNumCheck != serNum[i])
{
status = MI_ERR;
}
}
//SetBitMask(CollReg, 0x80); //ValuesAfterColl=1
return status;
}
/*
* Function?CalulateCRC
* Description?Use MF522 to caculate CRC
* Input parameter?pIndata--the CRC data need to be read?len--data length?pOutData-- the caculated result of CRC
* return?Null
*/
void CalulateCRC(uchar *pIndata, uchar len, uchar *pOutData)
{
uchar i, n;
ClearBitMask(DivIrqReg, 0x04); //CRCIrq = 0
SetBitMask(FIFOLevelReg, 0x80); //Clear FIFO pointer
//Write_MFRC522(CommandReg, PCD_IDLE);
//Write data into FIFO
for (i=0; i<len; i++)
{
Write_MFRC522(FIFODataReg, *(pIndata+i));
}
Write_MFRC522(CommandReg, PCD_CALCCRC);
//waite CRC caculation to finish
i = 0xFF;
do
{
n = Read_MFRC522(DivIrqReg);
i--;
}
while ((i!=0) && !(n&0x04)); //CRCIrq = 1
//read CRC caculation result
pOutData[0] = Read_MFRC522(CRCResultRegL);
pOutData[1] = Read_MFRC522(CRCResultRegM);
}
/*
* Function?MFRC522_Write
* Description?write block data
* Input parameters?blockAddr--block address;writeData--Write 16 bytes data into block
* return?return MI_OK if successed
*/
uchar MFRC522_Write(uchar blockAddr, uchar *writeData)
{
uchar status;
uint recvBits;
uchar i;
uchar buff[18];
buff[0] = PICC_WRITE;
buff[1] = blockAddr;
CalulateCRC(buff, 2, &buff[2]);
status = MFRC522_ToCard(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++) //Write 16 bytes data into FIFO
{
buff[i] = *(writeData+i);
}
CalulateCRC(buff, 16, &buff[16]);
status = MFRC522_ToCard(PCD_TRANSCEIVE, buff, 18, buff, &recvBits);
if ((status != MI_OK) || (recvBits != 4) || ((buff[0] & 0x0F) != 0x0A))
{
status = MI_ERR;
}
}
return status;
}
/*
* Function?MFRC522_Halt
* Description?Command the cards into sleep mode
* Input parameters?null
* return?null
*/
void MFRC522_Halt(void)
{
uchar status;
uint unLen;
uchar buff[4];
buff[0] = PICC_HALT;
buff[1] = 0;
CalulateCRC(buff, 2, &buff[2]);
status = MFRC522_ToCard(PCD_TRANSCEIVE, buff, 4, buff,&unLen);
}
but i mean inside the bit of code below which is what is activated when a card is detected i tried an if statement which was baisically if serNum matched the a string which was the ID of the card then to have the motor code in there but looking closer. serNUM seems to be hex which is converted to a string when printed out so i cant compare hex to a string.
man this is complicated, Ive decided to stop looking for the answer to this for a moment and work on the button and getting LED's just right and then have a break and come back and dig for the answer again 
