ex5-5.c

步进马达

#include <REGX51.H>
#define TIMER0_COUNT 0xEE11/*10000h-((12,000,000/(12*FREQ))*/
#define STOP            0
#define FORWARD         1
#define BACKWARD        2

char gotkey(); //声明函数

code forward[8]={0xfe,0xfc,0xfd,0xf9,0xfb,0xf3,0xf7,0xf6};//{0XFE,0XFD,0XFB,0X07};
//提高转速旋转度步进角度。

unsigned char timer0_tick=0,i=0,times=40,status=1;

static void timer0_isr(void) interrupt TF0_VECTOR using 1
{
  TR0=0;
  TL0=(TIMER0_COUNT & 0x00FF);
  TH0=(TIMER0_COUNT >> 8);
  TR0=1;
  timer0_tick++;
  if (timer0_tick==times) 
  {
    	timer0_tick=0;
		i++;
        if(i==8) i=0;
        if (status==FORWARD) 
		P2=forward[i];
        if (status==BACKWARD)
		{
			P2=forward[7-i];//反转时逆向取数。

		} 
  }
}
static void timer0_initialize(void)
{
  EA=0;   
  timer0_tick=0;
  TR0=0;
  TMOD=0x01;
  TL0=(TIMER0_COUNT & 0x00FF);
  TH0=(TIMER0_COUNT >> 8);
  PT0=1;
  ET0=1;
  TR0=1;
  EA=1;
}
void main (void)
{
     unsigned char command;
     timer0_initialize();
     do
	 {
         command=gotkey();
         if(command==15) status=FORWARD;      //按下F键
         if(command==11) status=BACKWARD;     //按下B键
         if(command==12) status=STOP;         //按下C键
         if((command==10) && (times>0)) 
		 times/=2;
                                              //按下A键
         if(command==13) 
		 times*=2;       //按下D键
     } while (1);                           //无穷循环 
}