Program to Make a Bidirectional Visitor Counter using IR sensor

// Program to make a bidirectional visitor counter using IR sensor

#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

{

p=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. For more details refer seven segment multiplexing.

{

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;

  }

}