#include<reg51.h>
#define p0 P0
#define p2 P2
unsigned int i,m0,m1,v1;
sbit c1=P2^4;
sbit c2=P2^5;
sbit c3=P2^6;
sbit c4=P2^7;
sbit r1=P2^0;
sbit r2=P2^1;
sbit r3=P2^2;
sbit r4=P2^3;
sfr a=0x90;
sbit rs=P3^7;
sbit rw=P3^6;
sbit en=P3^5;
void lcd();
void keypad();
int add(int m1,int m2);
void lcd_d( char val);
void lcd_in( char val);
void wait(int j)
{
long int i;
for(i=0;i<j;i++);
}
void main()
{
int m1,m2;
p2=0x0f;
lcd();
while(1)
{
keypad();
}
void keypad()
{
if( c3=0,c2=c1=c4=1,r1==0)
{
p0=0x20;
lcd_d('/');
}
if (c4=0,c2=c3=c1=1,r1==0)
{
p0=0x30;
lcd_d('*');
}
if(c1=0,c2=c3=c4=1,r2==0)
{
p0=0x40;
lcd_d('-');
}
if( c2=0,c1=c3=c4=1,r2==0)
{
p0=0x50;
lcd_d('+');
}
if( c3=0,c2=c1=c4=1,r2==0)
{
p0=0x60;
lcd_d('9');
}
if (c4=0,c2=c3=c1=1,r2==0)
{
p0=0x70;
lcd_d('8');
}
if(c1=0,c2=c3=c4=1,r3==0)
{
p0=0x80;
lcd_d('7');
}
if( c2=0,c1=c3=c4=1,r3==0)
{
p0=0x90;
lcd_d('6');
}
if( c3=0,c2=c1=c4=1,r3==0)
{
p0=0xa0;
lcd_d('5');
}
if (c4=0,c2=c3=c1=1,r3==0)
{
p0=0xb0;
lcd_d('4');
}
if(c1=0,c2=c3=c4=1,r4==0)
{
p0=0xc0;
lcd_d('3');
}
if( c2=0,c1=c3=c4=1,r4==0)
{
p0=0xd0;
lcd_d('2');
v1=v1+2;
}
if( c3=0,c2=c1=c4=1,r4==0)
{
p0=0xe0;
lcd_d('1');
}
if (c4=0,c2=c3=c1=1,r4==0)
{
p0=0xf0;
lcd_d('0');
}
}
