#include <reg51.h>
#define msec 1
unsigned int num=0;
sbit dig_ctrl_4=P1^3; //declare the control pins of seven segments
sbit dig_ctrl_3=P1^2;
sbit dig_ctrl_2=P1^1;
sbit dig_ctrl_1=P1^0;
unsigned int digi_val[10]={0x40,0xF9,0x24,0x30,0x19,0x12,0x02,0xF8,0x00,0x10};
unsigned int dig_1,dig_2,dig_3,dig_4,test=0;
unsigned char dig_disp=0;
sbit up=P3^5; //up pin to make counter count up
sbit down=P3^6; //down pin to make counter count down
void init() // to initialize the output pins and Timer0
{
up=down=1;
dig_ctrl_4 = 0;
dig_ctrl_3 = 0;
dig_ctrl_2 = 0;
dig_ctrl_1 = 0;
TMOD=0x01;
TL0=0xf6;
TH0=0xFf;
IE=0x82;
TR0=1;
}
void delay() //To provide a small time delay
{
TMOD=0x01;
TL0=0x36;
TH0=0xF6;
TR0=1;
while(TF0==0);
TR0=0;
TF0=0;
}
void display() interrupt 1 // Function to display the digits on seven segment.
{
TL0=0x36;
TH0=0xf6;
P2=0xFF;
dig_ctrl_1 = dig_ctrl_3 = dig_ctrl_2 = dig_ctrl_4 = 0;
dig_disp++;
dig_disp=dig_disp%4;
switch(dig_disp)
{
case 0:
P2= digi_val[dig_1];
dig_ctrl_1 = 1;
break;
case 1:
P2= digi_val[dig_2];
dig_ctrl_2 = 1;
break;
case 2:
P2= digi_val[dig_3];
dig_ctrl_3 = 1;
break;
case 3:
P2= digi_val[dig_4];
dig_ctrl_4 = 1;
break;
}
}
void main()
{
init();
while(1)
{
if(up==0&&down==1) //check if up pin is pressed
{
test++;
num=test;
dig_4=num%10;
num=num/10;
dig_3=num%10;
num=num/10;
dig_2=num%10;
dig_1=num/10;
if(test==9999)
test=0;
}
if(up==1&&down==0) //check if down pin is pressed
{
test–;
num=test;
dig_4=num%10;
num=num/10;
dig_3=num%10;
num=num/10;
dig_2=num%10;
dig_1=num/10;
if(test==0)
test=9999;
}
}
}