51单片机使用rc522的rfid读卡程序

以下是51单片机通过RC522读取RFID卡片的示例代码：

#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int

sbit led = P1^0;        //定义LED灯引脚
sbit beep = P1^5;       //定义蜂鸣器引脚

sbit SDA = P1^6;        //连接RC522模块的SDA引脚
sbit SCK = P1^5;        //连接RC522模块的SCK引脚
sbit MOSI = P1^7;       //连接RC522模块的MOSI引脚
sbit MISO = P1^4;       //连接RC522模块的MISO引脚
sbit RST = P1^3;        //连接RC522模块的RST引脚

uchar cardid[5];        //存放读到的卡号

//延时函数
void delay(uint i)
{
    while (i--);
}

//写RC522寄存器
void Write_MFRC522(uchar addr, uchar val)
{
    SDA = 0;
    SCK = 0;
    for (int i=0;i<8;i++)
    {
        SDA = (addr<<1)&0x80;
        SCK = 1;
        SCK = 0;
        addr <<= 1;
    }
    for (int i=0;i<8;i++)
    {
        SDA = (val<<1)&0x80;
        SCK = 1;
        SCK = 0;
        val <<= 1;
    }
    SDA = 1;
}

//读RC522寄存器
uchar Read_MFRC522(uchar addr)
{
    uchar val = 0;
    SDA = 0;
    SCK = 0;
    for (int i=0;i<8;i++)
    {
        SDA = (addr<<1)&0x80;
        SCK = 1;
        SCK = 0;
        addr <<= 1;
    }
    SDA = 1;
    for (int i=0;i<8;i++)
    {
        val <<= 1;
        SCK = 1;
        SCK = 0;
        if (MISO)
            val |= 0x01;
    }
    return val;
}

//复位RC522
void MFRC522_Init()
{
    Write_MFRC522(0x01, 0x0F);     //复位
    Write_MFRC522(0x2A, 0x8D);     //开启天线
    Write_MFRC522(0x2B, 0x3E);     //天线增益
    Write_MFRC522(0x2D, 0x30);     //信号强度调节
    Write_MFRC522(0x2C, 0);        //关闭M1卡片检测
}

//寻卡
uchar MFRC522_Request(uchar reqMode, uchar *TagType)
{
    uchar status;
    uint backBits;
    Write_MFRC522(0x0D, 0x07);     //寻卡
    TagType[0] = reqMode;
    status = MFRC522_ToCard(0x0E, TagType, 1, TagType, &backBits);
    if ((status != 0) || (backBits != 0x10))
        status = 1;
    return status;
}

//防冲突
uchar MFRC522_Anticoll(uchar *serNum)
{
    uchar status;
    uchar i;
    uchar serNumCheck = 0;
    uint unLen;
    Write_MFRC522(0x0D, 0x0C);     //防冲突
    Write_MFRC522(0x0E, 0x80);
    status = MFRC522_ToCard(0x0F, serNum, 1, serNum, &unLen);
    if (status == 0)
    {
        for (i=0;i<4;i++)
            serNumCheck ^= serNum[i];
        if (serNumCheck != serNum[i])
            status = 1;
    }
    return status;
}

//选择卡片
uchar MFRC522_SelectTag(uchar *serNum)
{
    uchar i;
    uchar status;
    uchar size;
    uint recvBits;
    uchar buffer[9];
    buffer[0] = 0x93;
    buffer[1] = 0x70;
    for (i=0;i<5;i++)
    {
        buffer[i+2] = serNum[i];
        buffer[7] ^= buffer[i+2];
    }
    MFRC522_CalculateCRC(buffer, 8, &buffer[8]);
    status = MFRC522_ToCard(0x0C, buffer, 9, buffer, &recvBits);
    if ((status == 0) && (recvBits == 0x18))
        size = buffer[0];
    else
        size = 0;
    return size;
}

//验证卡片密码
uchar MFRC522_Auth(uchar authMode, uchar addr, uchar *key, uchar *serNum)
{
    uchar status;
    uint recvBits;
    uchar i;
    uchar buff[12];
    buff[0] = authMode;
    buff[1] = addr;
    for (i=0;i<6;i++)
        buff[i+2] = key[i];
    for (i=0;i<4;i++)
        buff[i+8] = serNum[i];
    status = MFRC522_ToCard(0x0E, buff, 12, buff, &recvBits);
    if ((status != 0) || (!(Read_MFRC522(0x09) & 0x08)))
        status = 1;
    return status;
}

//读取数据
uchar MFRC522_Read(uchar addr, uchar *data)
{
    uchar status;
    uint recvBits;
    uchar i;
    uchar buff[6];
    buff[0] = 0x30;
    buff[1] = addr;
    MFRC522_CalculateCRC(buff, 2, &buff[2]);
    status = MFRC522_ToCard(0x0C, buff, 4, buff, &recvBits);
    if ((status == 0) && (recvBits == 0x90))
    {
        for (i=0;i<16;i++)
            data[i] = Read_MFRC522(0x01);
    }
    else
        status = 1;
    return status;
}

//写入数据
uchar MFRC522_Write(uchar addr, uchar *data)
{
    uchar status;
    uint recvBits;
    uchar i;
    uchar buff[18];
    buff[0] = 0xA0;
    buff[1] = addr;
    MFRC522_CalculateCRC(buff, 2, &buff[2]);
    status = MFRC522_ToCard(0x0C, buff, 4, buff, &recvBits);
    if ((status == 0) && (recvBits == 0x90))
    {
        for (i=0;i<16;i++)
            Write_MFRC522(0x01, data[i]);
    }
    else
        status = 1;
    return status;
}

//计算CRC16
void MFRC522_CalculateCRC(uchar *data, uchar length, uchar *result)
{
    uchar i;
    Write_MFRC522(0x22, 0x21);
    Write_MFRC522(0x23, length);
    MFRC522_ToCard(0x25, data, length, result, &i);
}

//与卡片通信
uchar MFRC522_ToCard(uchar cmd, uchar *sendData, uchar sendLen, uchar *backData, uint *backLen)
{
    uchar status = 1;
    uchar irqEn = 0x00;
    uchar waitIRq = 0x00;
    uchar lastBits;
    uint i;
    switch (cmd)
    {
        case 0x0C:
            irqEn = 0x12;
            waitIRq = 0x10;
            break;
        case 0x0E:
            irqEn = 0x77;
            waitIRq = 0x30;
            break;
        case 0x0D:
            irqEn = 0x77;
            waitIRq = 0x30;
            break;
        default:
            break;
    }
    Write_MFRC522(0x02, irqEn|0x80);
    ClearBitMask(0x04, 0x80);
    Write_MFRC522(0x01, 0x00);
    Write_MFRC522(0x09, 0x00);
    if (sendData != 0)
        Write_MFRC522(0x09, sendLen);
    Write_MFRC522(0x1D, waitIRq);
    SetBitMask(0x01, 0x80);
    for (i=0;i<sendLen;i++)
        Write_MFRC522(0x01, sendData[i]);
    Write_MFRC522(0x01, cmd);
    if (cmd == 0x0C)
        SetBitMask(0x0D, 0x80);
    i = 2000;   //等待时间
    while (1)
    {
        lastBits = Read_MFRC522(0x0C);
        if ((lastBits & 0x07) != 0)
            break;
        if (i == 0)
            break;
        i--;
    }
    if (i != 0)
    {
        if ((Read_MFRC522(0x06) & 0x1B) == 0x00)
        {
            status = 0;
            if (backData != 0)
            {
                *backLen = Read_MFRC522(0x07);
                if (*backLen > 0)
                {
                    for (i=0;i<*backLen;i++)
                        backData[i] = Read_MFRC522(0x09);
                }
            }
            if ((lastBits & 0x08) == 0)
                status = 1;
        }
    }
    ClearBitMask(0x01, 0x80);
    Write_MFRC522(0x0D, 0x00);
    return status;
}

//清除某位
void ClearBitMask(uchar addr, uchar mask)
{
    uchar tmp = Read_MFRC522(addr);
    Write_MFRC522(addr, tmp & (~mask));
}

//设置某位
void