AVR MCU key processing and key anti-jitter program

AVR MCU key processing and key anti-jitter program

#include  
#include
#include

unsigned char A,B;
unsigned char n; 
bit step1, step2, step3,step4;                     //Use several bit variables to memorize the button status
    
/

#include  
#include
#include

unsigned char A,B;
unsigned char n; 
bit step1, step2, step3,step4;                     //Use several bit variables to memorize the button status
    
//*************************************************** 
interrupt [10] void TC2_OVF(void)
{ 
 if(n<255) n++;                    
 if(PIND.2==1 && n>8) step1=1;                    //After the button is released for a certain period of time, it starts to enter the usable stateif
 (PIND.2==0 && step1) {step1=0; step2=1; n=0;}  //The button goes from the usable state to the pressed stateif
 (PIND.2==1 && step2) {step2=0; step3=1; n=0;}  //The button goes from the pressed state to the released state   
  
 //-------------------------------------------------    
                                                  //After the button is pressed...
 if(step2)
 {
   n++;
   if(n>60)                                       //If it is pressed for more than a certain period of time 
   {
     A+=1;
     n=40;
     ​​step4=1;
   }
 }    
  
 //-------------------------------------------------   
  
 if(step3)                                        //After releasing the button...
 {
   step3=0;
   if(step4) step4=0; else A+=1;
 }
}

//***************************************************
//www.avrdiy.com panxiaoyi
void main(void)
{    
 PORTB&=209;        
 DDRB|=46;                                        //Set the 4 LCD pins of the microcontroller to output 0         
 lcd_init();                                      //LCD initialization                 
 lcd_cls();                                       //Clear the screen, cursor returns to its original position      
  
 DDRD.2=0; 
 PORTD.2=1;                                       //PD2 is set as input, and the pull-up resistor is valid (connected to the button)   
 TCCR2B|=4;                                       //T/C2 uses the 64th frequency division of the system clock 
 #asm("sei");                                     //Global interrupt enable
 TIMSK2|=1;                                       //T/C2 count overflow interrupt enable  

 while (1)
 {    
   B+=1;      
   lcd_gotoxy(12,1); 
   lcd_putsf("AVRDIY.COM",10);   
     
   lcd_gotoxy(15,3);
   lcd_putchar(B/100+48);                         //Display variable B
   lcd_putchar(B/10%10+48);
   lcd_putchar(B%10+48);
    
   lcd_gotoxy(52,3);   
   lcd_putchar(A/100+48);                         //Display variable A
   lcd_putchar(A/10%10+48);    
   lcd_putchar(A%10+48);      
 };
}