Design And Construction Of A Microcontroller Based Infrared Object Counter

1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
The object counter is a cost effective and a simple system. It overcomes the problem of manual counting of objects. Everything is digital, so the signals can be used for further analysis and is compatible with other digital devices. If this system is implemented, then automation in the product counting can be achieved. Also, there is no hazardous elements used in the circuitry and hence it can be used even at hazardous atmospheres in an industrial area. The logic is very simple, the circuit has TSOP1738 sensor which detects whether there is a object or not in front of it. The controller will take the input from theTSOP1738 sensor, process it and sends the output to the seven segment display unit which will display the number of products counted. The TSOP1738 is a IR detecting device, it detects the IR rays transmitted at 38kHzfrequency (it is transmitting frequency not the frequency of the IR rays). Its output is not affected by the surrounding lights; therefore it will sense the object only.
This infrared object counter can be installed at the entry gate to count the total number of people entering any venue. For example, it can be used at the railway stations or bus stands to count the people arriving per day or week.
The counter uses an infrared transmitter-receiver pair and a simple, low-cost calculator. It works even in the presence of normal light. The maximum detection range is about 10 meters. That means the transmitter and the receiver are to be installed (at the opposite pillars of the gate) not more than 10 meters apart. No focusing lens is required. If an 8-digit calculator is used the counter can count up to 99,999,999 easily, and if a 10-digit calculator is used the counter can count up to 9,999,999,999.

1.2 PROBLEM STATEMENT
Traditional method of counting is done by appointing someone to count object and this involves much labour, wastes time and there is possibility of encountering human errors due to parallax or distraction. In other to solve this problem an object counter was built which is a digital object counting device which can be used to count the number of objects passing across a line , number of persons passing through a gate/door and so on.

1.3 AIM OF THE PROJECT
1. The main aim of the project is to count the number of objects.
2. To design an efficient model with low cost.

1.4 OBJECTIVE OF THE PROJECT
The objective of this project is to construct a device which can count the number of people entering a particular place. Infrared object counter can be installed at the entry gate to count the total number of people entering any venue.

1.5 APPLICATION OF THE PROJECT
The counter application is often used for:
i. Counting people traversing a certain passage or entrance. For example, in commercial buildings there are gates which control user access or presence often used to optimize energy consumption;
ii. Counting objects or merchandise in industrial sector;

1.6 LIMITATION OF THE PROJECT
i. The distance from the object is very important and in some cases the IR sensor is not suitable for these applications. If the distance from the object is greater than 20-30cm, the ultrasonic sensor can be a better choice.
ii. Entire circuit can be powered from a 5V DC supply.
LDR must be placed in an enclosure so that the light from LED alone falls on it.

1.7 PURPOSE OF THE PROJECT
People / Object counter circuit have a wide variety of applications in Banks, Hospitals, factories etc. The purpose of the project focuses on building an effective counter using IR as a sensing element and capable of counting from 0 to 999.

1.8 SCOPE OF THE PROJECT
This work is about a simple object counter/visitor counter using 8051 microcontroller. AT89S51 belonging to the 8051 family is the microcontroller used here. This circuit can count the number of objects passing across a line, number of persons passing through a gate/door and so on.

1.9 PROJECT WORK ORGANISATION
The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:
Chapter one of this work is on the introduction to the study. In this chapter, the background, significance, objective, scope, purpose, limitation and application, of the study were discussed.
Chapter two is on literature review of this study. In this chapter, all the literature pertaining to this work was reviewed.
Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.
Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.
Chapter five is on conclusion, recommendation and references.