//包含所需头文件
#include <avr/io.h>
#include <avr/interrupt.h>
/*------宏定义------*/
#define BIT(x)    (1<<(x))
void put_c(unsigned char dat);
void put_s(unsigned char *dat,unsigned char enter);
void find_start(void);
volatile unsigned char bit_array[256];
volatile unsigned char test_end = 0;
//端口初始化
void port_init(void)
{
    PORTB = 0x00;
    DDRB  = 0x08;
    PORTC = 0x00;
    DDRC  = 0x00;
    PORTD = 0x03;
    DDRD  = 0x02;
}
//定时T1初始化
void timer1_init(void)
{
    TCCR1B = 0x00;//停止定时器
    TIMSK |= 0x20;//中断允许
    TCNT1H = 0xFF;
    TCNT1L = 0xF8;//初始值
    TCCR1A = 0x00;
    TCCR1B = 0xC5;//启动定时器
}
//定时器T1输入捕捉中断服务程序
ISR(TIMER1_CAPT_vect)
{
    static unsigned char tr = 0;
    static unsigned char bit_no = 0;
    static unsigned char one_time = 0;
    TCCR1B = 0;
    TCNT1 = 0;
    if(ICR1 > 6)
    {
        bit_no = 0;
    }
    if(test_end == 0)
    {
        if(tr == 1)
        {
            bit_array[bit_no] = 1;
            bit_no++;
            if(bit_no == 0)
            {
                test_end = 1;
            }
            if(ICR1L > 4)
            {
                bit_array[bit_no] = 1;
                bit_no++;
                if(bit_no == 0)
                {
                    test_end = 1;
                }
            }
            TCCR1B = 0xC5;    //上升沿触发
            tr = 0;
        }
        else
        {
            bit_array[bit_no] = 0;
            bit_no++;
            if(bit_no == 0)
            {
                test_end = 1;
            }
            if(ICR1L > 4)
            {
                bit_array[bit_no] = 0;
                bit_no++;
                if(bit_no == 0)
                {
                    test_end = 1;
                }
            }
            TCCR1B = 0x85;    //下降沿触发
            tr = 1;
        }
    }
}
//定时器T2初始化
void timer2_init(void)
{
    TCCR2  = 0x00;//停止定时器
    ASSR   = 0x00;//异步时钟模式
    TCNT2  = 0x00;//初始值
    OCR2   = 0x2B;//匹配值
    TIMSK |= 0x00;//中断允许
    TCCR2  = 0x19;//启动定时器
}
//串口通信初始化
void usart_init(void)
{
    UCSRB = 0x00;//禁止中断
    UCSRA = 0x00;
    UCSRC = BIT(URSEL) | 0x06;
    UBRRL = 0x05;
    UBRRH = 0x00;
    UCSRB = 0x98;
}
void put_c(unsigned char dat)
{
    while(!(UCSRA & (1 << UDRE)))
    {
        
    }
    UDR = dat;
}
void put_s(unsigned char *dat,unsigned char enter)
{
    while(*dat)
    {
        put_c(*dat);
        dat++;
    }
    if(enter == 1)
    {
        put_c(0x0d);
        put_c(0x0a);
    }
}
void put_long(unsigned long dat)
{
    unsigned long temp = 1000000000;
    unsigned char i = 0;
    unsigned char out = 0;
    for(i = 0; i < 10; i++)
    {
        out = dat / temp;
        dat %= temp;
        temp /= 10;
        put_c(out + 48);
    }
//    out = dat % temp;
//    put_c(out + 48);
}
void init_devices(void)
{
    cli(); //禁止所有中断
    MCUCR  = 0x00;
    MCUCSR = 0x80;//禁止JTAG
    GICR   = 0x00;
    port_init();
    timer1_init();
    timer2_init();
    usart_init();
    sei();//开全局中断
}
//主函数
int main(void)
{
    unsigned char i = 0;
    init_devices();
//在这继续添加你的代码
    put_s("RFID Card Reader",1);
    while(1)
    {
        if(test_end == 1)
        {
            decode();
            test_end = 0;
        }
    }
    return 0;
}
void decode(void)
{
    unsigned char i,j,k;
    unsigned char id_code[11] = {0,0,0,0,0,0,0,0,0,0,0};
    unsigned char col_parity = 0;
    unsigned char row_parity = 0;
    unsigned char temp = 0;
    unsigned char start_data[20] = {1,0,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1};
    unsigned long rfid = 0;
    for(i = 0; i < 128; i++)
    {
        for(j = 0; j < 20; j++)
        {
            if(bit_array[i+j] != start_data[j])
            {
                break;
            }
        }
        if(j == 20)
        {
            put_s("",1);
            put_s("Find RFID Card.",1);
            i += 20;
            for(k = 0; k < 11; k++)
            {
                row_parity = 0;
//     读出五位数据
                temp = 0;
                for(j = 0; j < 5; j++)
                {
                    temp <<= 1;
                    if((bit_array == 0) && (bit_array[i+1] == 1))
                    {
                        temp |= 0x01;
                        if(j < 4)
                        {
                            row_parity += 1;
                        }
                    }
                    else if((bit_array == 1) && (bit_array[i+1] == 0))
                    {
                        temp &= 0xfe;
                    }
                    else
                    {
                        return;
                    }
                    i += 2;
                }
                id_code[k] = (temp >> 1);
                temp &= 0x01;
                row_parity %= 2;
                if(k < 10)
                {
                    if(row_parity != temp)
                    {
                        return;
                    }
                }
                else
                {
                    if(temp != 0)
                    {
                        return;
                    }
                }
            }
            if(k == 11)
            {
                put_s("ID Card :",0);
                for(j = 2; j < 10; j++)
                {
                    rfid += (((unsigned long)(id_code[j])) << (4 * (9 - j)));
                }
            }
            put_long(rfid);
            return;
        }
    }
}