Arduino 4 digit 7 segment multiplexing on Atmega8 using Timer 2 Interrupt

Here is the code to multiplex 4 digit 7 segment on Atmega8 using Timer 2 Interrupt. This code witll display digits array on seven segments. In our case we used 3024 to display on 7 segments.

#define segA 5
#define segB 6
#define segC 7
#define segD 8
#define segE 9
#define segF 10
#define segG 11


char disps[]={A0,A1,A2,A3};
char digits[]={4,2,0,3};
void digitMap(int val){
  
  int i=0;
  for(i=5;i<12;i++){
     digitalWrite(i,LOW);    
  }
   switch(val){
    case 0:
    digitalWrite(segA,HIGH);    
    digitalWrite(segB,HIGH);    
    digitalWrite(segC,HIGH);    
    digitalWrite(segD,HIGH);    
    digitalWrite(segE,HIGH);    
    digitalWrite(segF,HIGH);    
    break;
    
    case 1:
    digitalWrite(segB,HIGH);    
    digitalWrite(segC,HIGH);    
    break;
    
    case 2:
    digitalWrite(segA,HIGH);    
    digitalWrite(segB,HIGH);    
    digitalWrite(segD,HIGH);    
    digitalWrite(segE,HIGH);    
    digitalWrite(segG,HIGH); 
    break;
    
    case 3:
    digitalWrite(segA,HIGH);    
    digitalWrite(segB,HIGH);       
    digitalWrite(segC,HIGH);    
    digitalWrite(segD,HIGH);    
    digitalWrite(segG,HIGH);    
    break;
    
    case 4:
    digitalWrite(segB,HIGH);    
    digitalWrite(segC,HIGH);    
    digitalWrite(segF,HIGH);    
    digitalWrite(segG,HIGH);    
    break;
    
    default:
    digitalWrite(segG,HIGH);    
    break;
    
   }     
}



void setup(){
  
 pinMode(5,OUTPUT); 
 pinMode(6,OUTPUT);
 pinMode(7,OUTPUT);
 pinMode(8,OUTPUT);
 pinMode(9,OUTPUT);
 pinMode(10,OUTPUT);
 pinMode(11,OUTPUT); 
 pinMode(13,OUTPUT);
 pinMode(A0,OUTPUT);
 pinMode(A1,OUTPUT);
 pinMode(A2,OUTPUT);
 pinMode(A3,OUTPUT);
 digitalWrite(13,HIGH);
 
    OCR2 = 125;
    TCCR2 |= (1 << WGM21);
    TIMSK |= (1 << OCIE2);
    TCCR2 |= (1 << CS22); 
    sei();

}


void offAllDisps(){
 digitalWrite(A0,LOW); 
 digitalWrite(A1,LOW);
 digitalWrite(A2,LOW);
 digitalWrite(A3,LOW);
}
void loop(){
/*int i=0;
for(i=0;i<4;i++)
{
  digitMap(digits[i]);  
  digitalWrite(disps[i],HIGH); 
  delay(1);  
  offAllDisps();
  delay(3);
}
*/
 
  
  
}


volatile char disp_di = 0, ms_count=0;
ISR (TIMER2_COMP_vect)
{
  ms_count++;
  if(ms_count>3)ms_count=0;
  digitalWrite(A0,LOW); 
 digitalWrite(A1,LOW);
 digitalWrite(A2,LOW);
 digitalWrite(A3,LOW);
 if(ms_count<2){
   digitMap(digits[disp_di]);  
   digitalWrite(disps[disp_di],HIGH);
   disp_di++;
   if(disp_di>3)disp_di=0;
 }
 
}Code language: PHP (php)