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OUR PRESENTATION IS ON : BIDIRECTIONAL VISITOR COUNTER

WHAT IS BIDIRECTIONAL VISITOR COUNTER?

Many times we need to monitor the person/people visiting some place like Seminar hall, conference room or Shopping mall or temple. This project can be used to count and display the number of visitors entering inside any conference room or seminar hall. This is a bidirectional counter which means it works in a two way. That means counter will be incremented if person enters the room and will be decremented if a person leaves the room. LCD displays this value which is placed outside the room.

HOW DOES BIDIRECTIONAL VISITOR COUNTER WORK ?

THE BIDIRECTIONAL VISITOR COUNTER WORKS WITH MOST COMMONLY THREE COMPONENTS: SENSOR,CONTROLLER AND COUNTER DISPLAY.

THE SENSOR'S JOB IS TO PROVIDE INPUT TO THE CONTROLLER ABOUT ANY INTERRUPTION OR OBSERVATION AND THEN THE CONTROLLER WOULD RUN THE COUNTER UP OR DOWN DEPENDING UPON THE ACTION AND CHANGES IN THE UP/DOWN MODE DEPENDING ON THE SELECTION MADE ON THE 7 LCD DISPLAY ACCORDINGLY.

IN MOST OF THE MODELS, TWO INFRARED SENSORS MODULES ARE USED FOR UP OR DOWN COUNTING.

COMPONENTS USED :

1. PhotoDiode : A PhotoDiode is a semiconductor device that converts light into current. The current is generated when photons are absorbed in the photodiode. A small amount of current is also produced when no light is present. Photodiodes may contain optical filters, built-in lenses, and may have large or small surface areas.

2. Infra Red LED: An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared rays in the range of 760 nm wavelength. Such LEDs are usually made of gallium arsenide or aluminium gallium arsenide. They, along with IR receivers, are commonly used as sensors.

3. Dual Op-Amp IC : A Dual Op-Amp IC with high gain, frequency compensated operational amplifier with single power source.

4. 8051 Microcontroller AT89s52: Low-power, high-performance CMOS 8-bit microcontroller with 8KB of ISP flash memory.

PIN DIAGRAM OF 8051 MICROCONTROLLER

BLOCK DIAGRAM :

#include<reg51.h>
#define seven P2;
void delay();
sbit led = P1^1;
static unsigned char first = 0; 
static unsigned char  second = 0;
static signed char count = 0;
char codetable[10] = { 0xFE, 0x60, 0xDA, 0xF2, 0x66, 0xB6, 0xBE, 0xF0, 0xFE, 0xE6 };
void main()

{
	led = 1;
	P2 = 0x00;
	IE = 0x85;
	IT0 = 1;
	IT1 = 1;
	while(1)
	{
	P2 = codetable[count];
  }
}
	void init() interrupt 0 
	{
		if((first == 0) && (second == 0))
	{ first = 1;
		 second = 0;
		 
	}
		else if((first == 0)&&(second == 1))
		{ count = count - 1;
			  second = 0;
			  first = 0;
		}
		
	}
	void init1() interrupt 2
	{
		 if((first == 1)&&(second ==0))
		 { count = count +1;
		   second = 0;
			 first =0;
			 
     }
		 else if((first == 0) && (second == 0))
		 { second = 1;
       first = 0; }			  
	 }

APPLICATIONS :

1. In Classrooms to keep Track of number of Persons in the room