源代码：

#include<reg51.h>

#define uchar unsigned char

#define uint unsigned int

#define OUT P2

sbit pos = P1^0;

sbit neg = P1^1;  

uint TIME;

uchar code turn[] = {0x02,0x06,0x04,0x0c,0x08,0x09,0x01,0x03};

void main()

{

uchar a;

  OUT = 0x03;

TMOD = 0x01;      

TH0 = 0x3c;      

TL0 = 0xb0;   

EA = 1;           

ET0 = 1;        

TR0 = 1;        

/*

定时器时间=（65536-15536）*12/12=5000us=5ms    

电机转速计算n=60000/(10*8)=750 r/min

*/

while(1)

{

if (pos&&neg) TIME=0;

if (!pos)              

{

if (TIME==2)

{

a = a<8?a+1:0;

OUT = turn[a];

TIME = 0;

}

}

if (!neg)

{

if (TIME==2)

{

a = a>0?a-1:7;

OUT = turn[a];

TIME = 0;

}

}

   }    

}

void timer(void)interrupt 1   using 0

{

   TH0=0x3c;  

   TL0=0xb0;

   TIME++;

}