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A Great Cost Effective Way To Count The People Enters Through The Door

(PEOPLE COUNTER)

Sumpi Riningam(Roll no - 10002040) and Ravindra Kumar Meena(Roll no - 10002041)

Department of Electrical Engineering, Indian Institute of Technology Gandhinagar, Ahmedabad 382424, India

Submission date : 18/10/2011

This paper presents a novel implementation method of people counting. The people counter setup at a doorway counts people as they enter

and leave , and this divide by 2 get the people count. It uses the principle and working of a hall effect sensor. The counter counts the number

of times a pulse is produced in the hall effect sensor. It suits counting visitors or customers at Libraries, Museums and Art-galleries.

The invention of people counter is backed up

by its versatile application and increasing

necessity. For instance - in retail stores, the use

of people counting system is necessary to

calculate the conversion rate i.e. thepercentage of a stores visitor that makes

purchase which then acts as stores

performance indicator. Shopping mall

marketing professionals measures marketing

effectiveness with sales, and also uses visitor

statistics to measure marketing effectiveness.

Also certain public locations are rated to hold

certain number of people. Thus in this

situation people counter is used to assure that a

building is below the safe level of occupancy.All these gave birth to the invention to people

counter.

We use a Hall sensor with a magnet. The

output voltage across the LED is connected to

the display driver input. The magnet goes on

the edge of the door and a Hall sensor goes on

the door frame so that it lines up with the

magnet when the door is closed. At this point,

LED is in off mode and when opened LED is

in on mode. Thus the voltage across the LED

acts as a pulse to the input of the display driver

circuit which then counts the number of times

a pulse is generated(which is equivalent to

number of times a person enter or leaves a

room).

*1) Hall Effect Sensor: When the device is

placed within a magnetic field, the magnetic

flux lines exert a force on the semiconductor

material which deflects the charge carriers,electrons and holes, to either side of the

semiconductor slab. This movement of charge

carriers is a result of the magnetic force they

experience passing through the semiconductor

material. As these electrons and holes move

side wards a potential difference is producedbetween the two sides of the semiconductor

material by the build-up of these charge

carriers. Then the movement of electrons

through the semiconductor material is affected

by the presence of an external magnetic field

which is at right angles to it. To generate a

potential difference across the device the

magnetic flux lines must be perpendicular,

(90o) to the flow of current.

*2) Display Driver Circuit: This shows how a

Seven Segment Display is driving with the

help of the 5 stage Johnson decade counter IC

CD4033.The IC has counter and decoder in

one package. It converts the Johnson codes

into Seven Segment Decoder output to drive

the common cathode display. The display

shows the counts in the form of numerical

display. The display driver circuit is powered

from a 9 volt DC supply and the outputs of IC

are connected to the Common Cathode Seven

Segment display LT 543. The IC countscontinuously up to 9 if the Clock Enable,

Strobe and Reset pinsare grounded. The cycle

repeats till the reset pin gets a High pulse. The

input of CD 4033is a sensitive Schmitt trigger

and readily accepts positive to negative

transition pulses to starts the counting. The

counter advances and the signals are available

at the outputs as decoded signals which drive

the numerical display.

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Fig: Schematic Diagram of Display Driver

Cricuit

Pictures:showing the working of people

counter

From observations :

Vo2=2V (fixed)

Vo1=2.5V (when no magnetic field is

applied)

Vo1=0.23 (when NP of magnet is close to

the sensor)

The voltage Vo = A (Vo1-Vo2) is thus

negative and the diode is reversed biased when

door is closed. However Vo is positive and

current flows through the diode when

forward biased i.e when door is opened

(reasoning with *1). This output voltage is

fetch to the input of display driver circuitwhich then gives the numerical output (as

explained in *2).

The number displayed in the seven segment

display is the result of the experiment. The

result can be visualize from the video given by

this link:

http://www.youtube.com/watch?v=tYsmzyoQ

G8c&feature=feedu

The experiment is in accordance with the

theory with the limitation that it counts just up

to nine. However this limitation can be

overcome by cascading the IC to connect

many displays to count up to desired value. It

is cheap, portable and easy to use.

This method of counting can be used as safetyreasons like it counts how many number of

times the meters lock located at home is

broken in certain time period. It could be used

to detect any kind of movement, counts how

many people enter or exit and enables to make

sensibility settings.

http://www.youtube.com/watch?v=tYsmzyoQG8c&feature=feeduhttp://www.youtube.com/watch?v=tYsmzyoQG8c&feature=feeduhttp://www.youtube.com/watch?v=tYsmzyoQG8c&feature=feeduhttp://www.youtube.com/watch?v=tYsmzyoQG8c&feature=feeduhttp://www.youtube.com/watch?v=tYsmzyoQG8c&feature=feedu

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References:

http://www.flatline.net/journal/2009/09/20/hall

-effect-sensors-and-arduino-interrupts/

http://electroschematics.com/5312/display-

driver/

http://en.wikipedia.org/wiki/People_counter

http://www.flatline.net/journal/2009/09/20/hall-effect-sensors-and-arduino-interrupts/http://www.flatline.net/journal/2009/09/20/hall-effect-sensors-and-arduino-interrupts/http://www.flatline.net/journal/2009/09/20/hall-effect-sensors-and-arduino-interrupts/http://electroschematics.com/5312/display-driver/http://electroschematics.com/5312/display-driver/http://electroschematics.com/5312/display-driver/http://en.wikipedia.org/wiki/People_counterhttp://en.wikipedia.org/wiki/People_counterhttp://electroschematics.com/5312/display-driver/http://electroschematics.com/5312/display-driver/http://www.flatline.net/journal/2009/09/20/hall-effect-sensors-and-arduino-interrupts/http://www.flatline.net/journal/2009/09/20/hall-effect-sensors-and-arduino-interrupts/