The ATmega16 MCU scientific calculator program (with addition, subtraction, multiplication and division functions) has been completed

Supports unsigned long integer value calculations up to eight bits, and signed operations and other calculation functions will be added later.

#include
#include
//#include
#define uchar unsigned char
#define uint unsigned int
#define ulong unsigned long
#define EA SREG|=BIT(7)
uchar temp ,old,key_turn,flag=0;
ulong datA=0,datB=0;
const uchar wela[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
const uchar tab[11]={ 0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x00};
extern uchar dat[8]={0,0,0,0,0,0,0,0};
extern uchar dat_right[]={0x0a,0x0a,0x0a,0x0a,0x0a,0x0a,0x0a,0x0a};
void delay( uint z)
{
while(z--);
}
void display(uchar z)
{
uchar i;
while(z--)
for(i=0;i<8;i++)
{
PORTB=wela[i];
PORTD= tab[dat_right[i]];
delay(30);
PORTB=0XFF;
}
}

void clean_junk()
{
uchar i,p=0;
for(i=0;i<8;i++)
{
dat_right[i]=0x0a;
}
for(i=0;i<8;i++)
{
if(dat[ i]>0)p=1;
if(p)dat_right[i]=dat[i];
}
}
void delete()
{
uchar i;
for(i=0;i<8;i++)
{
dat[i] =0;
}
clean_junk();
}
void disan_he()
{
ulong i;
     i=dat[0]*1e7+dat[1]*1e6+dat[2]*1e5+dat[3]*1e4+dat[4 ]*1e3+dat[5]*1e2+dat[6]*1e1+dat[7];
if(flag)datB=i;
else datA=i;
flag=1;
delete();
}
void disan_fen()
{
dat[0]=datA/1e7;
dat[1]=datA%10000000/1000000;
dat[2]=datA%1000000/100000;
dat[3]= datA%100000/10000;
dat[4]=datA%10000/1000;
dat[5]=datA%1000/100;
dat[6]=datA%100/10;
dat[7]=datA%10;
flag= 0;

}
void move()
{
uchar i;
if(temp>0&temp<0x0b)
{
for(i=0;i<8;i++)
{
dat[i]=dat[i+1];
}
if(temp==0x0a ){dat[0]=0;temp=0;}
dat[7]=temp;temp=0;
}
}
void clean()
{
uchar i;
flag=0;
for(i=0;i<8;i++ )
{
dat[i]=0;
}
temp=0;
old=0;
datA=0;
datB=0;
}
void disan()
{
if(temp>0&temp<0x11)switch(temp)
{
case 0x0e:clean( );break;
case 0x0b:old=temp;temp=0;disan_he();break;
case 0x0c:old=temp;temp=0;disan_he();break;
case 0x0d:old=temp;temp=0;disan_he();break;
case 0x10:old=temp;temp=0;disan_he();break;
case 0x0f:switch(old)
{
case 0x0b:if(flag)disan_he( );datA=datA/datB;old=0;temp=0;disan_fen();break;
case 0x0c:if(flag)disan_he();datA=datA*datB;old=0;temp=0;disan_fen() ;break;
case 0x0d:if(flag)disan_he();datA=datA-datB;old=0;temp=0;disan_fen();break;
case 0x10:if(flag)disan_he();datA=datA+datB ;old=0;temp=0;disan_fen();break;
default:temp=0;old=0;break;
}break;
default:move();temp=0;break;
}

// disan_fen();delete();

}
void diskey()
{
uchar i,n;
const uchar code[]={0xFE,0xFD,0xFB,0xF7};
if(temp==0x00)for(i=0;i<4;i++)
{
PORTA=code [i];
temp=PINA;
if(~temp&0xf0)i=6;
while(~PINA&0xf0)display(1);
PORTA=0xff;
}
if(temp>0x10)switch(temp)
{
case 0xEE:temp=0x07; break;
case 0xDE:temp=0x08;break;
case 0xBE:temp=0x09;break;
case 0x7E:temp=0x0b;break;
////////////////////// ////
case 0xED:temp=0x04;break;
case 0xDD:temp=0x05;break;
case 0xBD:temp=0x06;break;
case 0x7D:temp=0x0c;break;
///////////////////////// //
case 0xEB:temp=0x01;break;
case 0xDB:temp=0x02;break;
case 0xBB:temp=0x03;break;
case 0x7B:temp=0x0d;break;
//////////// ////////////
case 0xE7:temp=0x0e;break;
case 0xD7:temp=0x0a;break;
case 0xB7:temp=0x0f;break;
case 0x77:temp=0x10;break;
// /////////////////////////
default:temp=0x00;break;
}
disan();

}
void main()
{
  MCUCSR|= 1<  MCUCSR|= 1<DDRC=0XFF;
DDRB=0XFF;
DDRD=0XFF;
DDRA=0X0F;
while(1)
{
display(1);
diskey();
clean_junk();
}
}