Stc89c52rc controls the stepping motor, and the program card is in the first line of main,

#include<reg52.h>#define uint unsigned int#define uchar unsigned charsbit maicong=P2^5;// Motor pulse output , Initial low level sbit fangxiang=P2^6;// Motor direction output , Low level after initialization sbit EN=P2^7;// Motor enable , Initial high level sbit XWKG=P2^4;// Initial position confirmation port , Low level active , call ZIJIAN Subroutines sbit k0=P1^0;// start-up , call START Subroutines sbit k1=P1^1;// stop it , call TINGZHI Subroutines sbit k2=P1^2;// Speed up , call SUDUZ Subroutines sbit k3=P1^3;// Speed down , call SUDUJ Subroutines sbit k4=P1^4;// Step size plus , call BUCHANGZ Subroutines sbit k5=P1^5;// Step minus , call BUCHANGJ Subroutines uint tt=200;// If you need ？？uint step=1100;// ditto uint num=18;void keyscan();// Keyboard scanner , Program completion void delayms(uint ms);// Millisecond variable delay program void delayus(uint us);// Microsecond variable delay program , Used for low-level output delay , The frequency is adjusted by changing the low level .void delay(uint us);// Microsecond delay program , Used for pulse high-level output delay void baidong();//void ZIJIAN();// Program completion void START();// Corresponding k0void TINGZHI();// Corresponding k1void SUDUZ();// Corresponding k2void SUDUJ();// Corresponding k3void BUCHANGZ();// Corresponding k4void BUCHANGJ();// Corresponding k5void JIUQIANYISHEN();// Corresponding k6void main(void){    _    maicong = 0;_        fangxiang = 1;        IT1 = 1;                        //set INT1 int type (1:Falling only 0:Low level)        EX1 = 1;                        //enable INT1 interrupt        EA = 1;                         //open global interrupt switch        ZIJIAN();               while(1);// Wait for the key command , here PWM=0;DIR=0.}/* Lower level external interrupt 2, Responsible for key operation , Start now 、 stop it 、 Acceleration and deceleration 、 Step addition and subtraction 、 Start of automatic running program */void exint1() interrupt 2           //(location at 0013H){                  keyscan();                                  }void keyscan(){ while(1) {         if(k0==0)    START();    else if(k1==0)    TINGZHI();// stop it , Return to the initial position     else if(k2==0)    SUDUZ();// Speed increase     else if(k3==0)    SUDUJ();// Speed down     else if(k4==0)    BUCHANGZ();// Step size increases     else if(k5==0)    BUCHANGJ();// Step minus     else if(k6==0)    JIUQIANYISHEN();// Nine is shallow and one is deep     else if(XWKG==0) ZIJIAN();// The initial position switch is on , Motor commutation , turn }}void ZIJIAN()  {                EN=0;// Motor enable , Can rotate freely                 fangxiang=1;        while(XWKG==0)     {    maicong=1;    delay(1);    maicong=0;        delayus(tt);        }               while(XWKG==1)                        {         fangxiang=0;        maicong=1;    delay(1);    maicong=0;        delayus(tt);// It is necessary to determine the rotation angle with the limit switch                                                             }          EN=1;// Motor enable , Cannot rotate freely         delayms(50);}        void START()  {        EN=0;                step=1100;//50*55 Maximum moving steps , It is possible to trigger the limit switch                 delayms(50);        while(1)                {                            baidong();            }}void TINGZHI(){        while(1);    }void SUDUZ(){   tt=tt-5;   if(tt<1)    tt=1;    while(k2==0);}void SUDUJ(){   tt=tt+5;   if(tt>255)    tt=255;    while(k3==0);}void BUCHANGZ(){   step=step+5;   if(step>2750)    step=2750;    while(k4==0);}void BUCHANGJ(){   step=step-5;   if(step<50)    step=50;    while(k5==0);}/* External interrupt 0（ highest ）, Responsible for interrupting external interrupts  2, That is, the trigger of the limit switch */void exint0() interrupt 0           //(location at 0003H){    while(1);}    void baidong()    {     EN=0;// Motor enable , Can rotate freely                while(step--)//step The value range is less than the subdivision value *55     {    maicong=1;// initial pwm The output is low level , When you start, it will become high （ Common Yin connection ）    delay(1);// Time delay 4 Microsecond , The pulse width is 5 Microsecond     maicong=0;// Low level     delayus(tt);// Time delay 9 Microsecond , Low level width 10 Microsecond , Adjust this delay value to change the speed      }   fangxiang=~fangxiang;// Commutation     }void delay(uint xus)    {        uint m;        for(m=0;m<xus;++m);            }void delayus(uint tt)    {        uint n;        for(n=0;n<tt;++n);// Variable delay program ？？？    }void delayms(uint xms)    {        uint x,y;        for(x=0;x<xms;++x)        for(y=0;y<110;++y);    }