//PROGRAM TO DISPLAY 1234 shifting from left to right
//global declaration
volatile uint8_t *outa;
volatile uint8_t address=0x01,store=0x00;
volatile uint8_t arr_pattern[]={0x10,0x30,0x10,0x10,0x10,0x10,0x38,0x00};
volatile uint8_t arr_pattern2[]={0x38,0x44,0x04,0x08,0x10,0x20,0x7c,0x00};
volatile uint8_t arr_pattern3[]={0x38,0x44,0x04,0x18,0x04,0x44,0x38,0x00};
volatile uint8_t arr_pattern4[]={0x08,0x18,0x28,0x48,0x7c,0x08,0x08,0x00};
volatile uint8_t dum=0x00,dum2=0x00;
volatile long i,j,k,m,n;

void setup() {
  // put your setup code here, to run once:
volatile uint8_t *dira;
dira=0x21;*dira=0xff;
outa=0x22;
display_left_to_right();
}

void loop() {
  // put your main code here, to run repeatedly:


}

void display_left_to_right(){
  for(m=0;m<32;m++){
  for(k=0;k<8;k++){
     *outa&=~0x02;

    //display1
  //address
address=0x01;
address=address+k;;
for(i=7;i>=0;i--){
store=(address>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}
//data transfer for left to right
if(m<=7){
dum=arr_pattern4[k]<<(7-m);
}
//data transfer from right to left
else{
dum=arr_pattern4[k]>>(m-7);
if(m<=15){
dum2=arr_pattern3[k]<<(15-m);
dum=dum|dum2;
}
else{
  dum=arr_pattern3[k]>>(m-15);
  if(m<=23){
   dum2=arr_pattern2[k]<<(23-m);
   dum=dum|dum2;
  }
  else{
   dum=arr_pattern2[k]>>(m-23);
   if(m<=31){
   dum2=arr_pattern[k]<<(31-m);
   dum=dum|dum2;
   }
  }
}
}
//data transmission
for(i=7;i>=0;i--){
store=(dum>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}



//3 displays zeroes
  if(m<8){
    for(j=0;j<3;j++){
    address=0x01;
    address=address+k;
    for(i=7;i>=0;i--){
    store=(address>>i)&0x01;
    if(store)*outa|=0x01;
    else *outa&=~0x01;
    *outa|=0x04;
    for(j=0;j<100;j++);
    *outa&=~0x04;
    }
    for(n=0;n<8;n++){ 
   *outa&=~0x01;
   *outa|=0x04;
   for(j=0;j<100;j++);
   *outa&=~0x04;
}
  }
  }
   else{
  //display2
  //address
address=0x01;
address=address+k;;
for(i=7;i>=0;i--){
store=(address>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}
//data transfer for left to right
if(m<=14){
dum=arr_pattern4[k]<<(15-m);
}
//data transfer from right to left
else{
dum=arr_pattern4[k]>>(m-15);
if(m<=23){
  dum2=arr_pattern3[k]<<(23-m);
  dum=dum|dum2;
}
else{
  dum=arr_pattern3[k]>>(m-23);
  if(m<=31){
   dum2=arr_pattern2[k]<<(31-m);
   dum=dum|dum2;
  }
}
}
//data transmission
for(i=7;i>=0;i--){
store=(dum>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}
  }
//2 displays zeroes
  if(m<16){
    for(j=0;j<2;j++){
    address=0x01;
    address=address+k;
    for(i=7;i>=0;i--){
    store=(address>>i)&0x01;
    if(store)*outa|=0x01;
    else *outa&=~0x01;
    *outa|=0x04;
    for(j=0;j<100;j++);
    *outa&=~0x04;
    }
    for(n=0;n<8;n++){ 
   *outa&=~0x01;
   *outa|=0x04;
   for(j=0;j<100;j++);
   *outa&=~0x04;
}
  }
  }
      else{
  //display3
  //address
address=0x01;
address=address+k;;
for(i=7;i>=0;i--){
store=(address>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}
//data transfer for left to right
if(m<=22){
dum=arr_pattern4[k]<<(23-m);
}
//data transfer from right to left
else{
dum=arr_pattern4[k]>>(m-23);
if(m<=31){
  dum2=arr_pattern3[k]<<(31-m);
  dum=dum|dum2;
}
}
//data transmission
for(i=7;i>=0;i--){
store=(dum>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}
  }
//1 displays zeroes
  if(m<24){
    address=0x01;
    address=address+k;
    for(i=7;i>=0;i--){
    store=(address>>i)&0x01;
    if(store)*outa|=0x01;
    else *outa&=~0x01;
    *outa|=0x04;
    for(j=0;j<100;j++);
    *outa&=~0x04;
    }
    for(n=0;n<8;n++){ 
   *outa&=~0x01;
   *outa|=0x04;
   for(j=0;j<100;j++);
   *outa&=~0x04;
}
  }
         else{
  //display4
  //address
address=0x01;
address=address+k;;
for(i=7;i>=0;i--){
store=(address>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}
//data transfer for left to right
if(m<=31){
dum=arr_pattern4[k]<<(31-m);
}
//data transmission
for(i=7;i>=0;i--){
store=(dum>>i)&0x01;
if(store)*outa|=0x01;
else *outa&=~0x01;
*outa|=0x04;
for(j=0;j<100;j++);
*outa&=~0x04;
}
  }


*outa|=0x02;
  }
  dum=0x00;dum2=0x00;
  for(j=0;j<100000;j++);
}
}