//1 bit calculator

#include "lcd.h"
#include "operation.h"

void setup() {
  // put your setup code here, to run once:
init();

}

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


volatile char *port_d =(volatile char*)0x2A;
volatile char *port_a =(volatile char*)0x21;
volatile char *port_c =(volatile char*)0x27;

volatile char *row =(volatile char*)0x2B;
volatile char *col =(volatile char*)0x20;
volatile char *seg =(volatile char*)0x28;
   
volatile char x,j,k,count=0,num1,op,num2,result=0,rs;
volatile long i;
volatile int arr[]={0x01,0x02,0x04,0x08};
volatile int arr1[]={1,2,3,'+'};
volatile int arr2[]={4,5,6,'-'};
volatile int arr3[]={7,8,9,'*'};
volatile int arr4[]={'=','0','0','/'};
volatile int digit[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d};

x = *col;
while(1)
{

  for(k=0;k<4;k++)         //row scan
  {
    *row = 1 << k;          //row scan
   if(x=*col) {count++;
    if (*row == 1)
       for(j=0;j<4;j++)
       {
          x = *col;
          if((x & arr[j]) == arr[j]) 
          {
            if(count == 1){ num1 = arr1[j];}
            if(count == 2){ op = arr1[3];}
            if(count == 3){ num2 = arr1[j];} 
                
          }
       }
    if (*row == 2)
       for(j=0;j<4;j++)
       {
          x = *col;
          if((x & arr[j]) == arr[j]) 
          {
            if(count == 1){ num1 = arr2[j];}
            if(count == 2){ op = arr2[3];}
            if(count == 3){ num2 = arr2[j];}
           }
       }
    if (*row == 4) 
       for(j=0;j<4;j++)
       {
          x = *col;
          if((x & arr[j]) == arr[j]) 
          {
            if(count == 1){ num1 = arr3[j];}
            if(count == 2){ op = arr3[3];}
            if(count == 3){ num2 = arr3[j];}
          }
       }
       if (*row == 8) 
       for(j=0;j<4;j++)
       {
          x = *col;
          if((x & arr[j]) == arr[j]) 
          {
             if(count == 2){ op = arr4[3];}
              if(count >=4){ rs = arr4[0];} 
  
          }
        }
       

       if(count == 0)*seg = digit[0];
       if(count == 1)*seg = digit[1];
       if(count == 2)*seg = digit[2];
       if(count == 3)*seg = digit[3];
       if(count == 4)*seg = digit[4];   
       
        lcd_configuration(0x02);
        lcd_configuration(0x01);
   
        lcd_configuration(0x0c);
        display(num1+0x30);
       
       lcd_configuration(0x0c);
        display(op);
      
         lcd_configuration(0x0c);
        display(num2+0x30);
      
       lcd_configuration(0x06);
        display(rs);
        
         if(op == arr1[3])result = add(num1,num2);
         if(op == arr2[3])result = sub(num1,num2);
         if(op == arr3[3])result = mul(num1,num2);
         if(op == arr4[3])result = division(num1,num2);
         if(rs == arr4[0])
         {
             lcd_configuration(0x06);
             if(result >= 10)
             {
              volatile char temp;
              temp = result;
              result=temp/10;
              display(result+0x30);
              result=temp%10;
              display(result+0x30);
              break;
             }
             display(result+0x30);
             
         }          
   }
   }
 }
}