AT89S52 controls hybrid stepper motor C program

#include   //Include printf header file
#define uint unsigned int
#define uchar unsigned char

sbit cp  = P2^0;   //Pulse input terminal
sbit dir = P2^1;   //Direction control terminal
sbit free = P2^2;   //Offline control terminal, usually connected to high

sbit jia_su = P1^0;   //Declaration of acceleration key 1
sbit jian_su = P1^1;  //Deceleration key 2 declaration
sbit fang_xiang = P1^2;  //Declaration of direction switch key 3
sbit ting = P1^3;   //Declaration of stop key 4
uint num;
void uart_Init();   //Serial port initialization sub-function declaration

void delay(uint z)  //ms子函数
{ 
 uint x,y;
 for(x = 0;x   for(y = 0;y<120;y++);
}

void delay1(uint z)   //Motor delay sub-function us level
{ 
 uint x;
 for(x = 0;x   
}

void init()    //Initialize motor and serial port sub-function
{ 
 num = 2;
   dir = 1;
 free = 1;
 uart_Init();
}

void key_scan()   //Keyboard control subfunction
{
 if(jia_su == 0)   //Judge whether the accelerator key is pressed
 {
  delay(5);   //Delay debounceif
  (jia_su == 0)  //Judge whether the accelerator key is pressed again
  {
   num++;   //num (representing the motor speed) increasesif
   (num>4)   
   {num=4;}
   while(!jia_su);   //Release detection
     delay(5);
     while(!jia_su);
    printf("num = %dn",num);//View the num value through the serial port
  }
 }
 if(jian_su == 0)   //Judge whether the deceleration key is pressed
  {
   delay(5);   //Delay debounceif
   (jian_su == 0)  //Judge whether the deceleration key is pressed again
   {
    num--;   //num (representing the motor speed) decreasesif
    (num<1)
    {num=0;} 
    while(!jian_su);  //Release detection
     delay(5);
     while(!jian_su);
    printf("num = %dn",num);  //View the num value through the serial port
   }
  }
 if(fang_xiang ==0)   //Judge whether the direction switch key is pressed
 { 
  delay(5);    //Delay debounceif
  (fang_xiang == 0)
  {
   dir =~dir;   //Direction changewhile
   (!fang_xiang);   //Release detectiondelay
    (5);
    while(!fang_xiang);
   printf("dir = %dn",dir);
  }
 }
 if(ting ==0)   //Judge whether the stop key is pressed
 { 
  delay(5);    //Delay debounceif
  (ting == 0)
  {
   num = 0;   //Stopwhile
   (!ting);   //Release detectiondelay
    (5);
    while(!ting);
  }
 }
 
 switch(num)
 { 
  case 0: cp = 1; break;   //Motor stopscase
  1:      //Rotate at low speed
  { 
   
   
    cp = 1;
    delay1(20);
    cp = 0;
    delay1(20); 
  
  }
  break;

  case 2:    //rotate at medium speed
  { 
   
   
    cp = 1;
    delay1(15);
    cp = 0;
    delay1(15); 
   
  }
  break;
  
  case 3:    //rotate at high speed
  { 
   
   
    cp = 1;
    delay1(10);
    cp = 0;
    delay1(10); 
   
  }
  break;

  case 4:    //Rotate at a higher speed
  { 
   
   
    cp = 1;
    delay1(5);
    cp = 0;
    delay1(5);
    
  }
  break;
 }
 
}
void main()
{ 
 init();   //Call initialization subfunction
 while(1)
 { 
  key_scan();   //Continue keyboard scanning
 } 
 
}