Project Materials

Design and Construction of a Wireless Temperature Telemetry Device

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND

Temperature has been discovered to be the second most measured physical quantity, time been the First. This shows the need to measure temperature is very necessary, the measurement thus has to be efficient and convenient.

Years back, crude methods were used in measurement of temperature of objects, colors and hotness of materials were used in temperature measurement for example color red i.e., redness of material means it is hot. But this was not enough to measure the degree of hotness especially when you need to heat a particular material to a certain temperature.

The need to assign values to temperature measurement led to the invention of the conventional mercury thermometer, though this method was widely accepted then, it was indirect and measurement was prone to errors.

The need for accuracy and precision in measurement led to the digital thermometer, which is more accurate and helps eliminate parallax error during measurement.

In this information era where the wired and wireless technology applications is widely used by lots of industries and hobbyists, group of experts make a research on how to implement the use of these technologies in monitoring the temperature in a more precise and reliable way.

Telemetry can be described as a highly automated communications process that involves the collection of measurements and other data at remote or inaccessible points prior to transmission to receiving equipment for monitoring and control purposes. The word telemetry is usually associated with wireless methods.

Temperature telemetry is therefore the measurement of temperature of substances, things, physically inaccessible locations, and transferring the measured temperature value to a desired or more accessible location.

1.2 OVERVIEW OF THE PROJECT WORK

As we know, radio frequencies refer to the frequencies that fall within the electromagnetic spectrum associated with radio wave propagation. When applied to an antenna, RF current creates electromagnetic fields that propagate the applied signal through space.

Any RF field has a wavelength that is inversely proportional to the frequency and this means that the frequency of an RF signal is inversely proportional to the wavelength of the field.

It goes the same with this project that used the application of radio frequencies by using RF transmitter and RF receiver to monitor the temperature of object under test.

The temperature of the object under test is sensed by an analogue temperature sensor IC (LM35DZ) and temperature is converted into equivalent voltage (which is about 0.01V/˚C) by the IC and it is in turn sent to the programmed ATMEGA328 microprocessor which processes the signal data and sends it to the remote end through the RF transmitter.

At the remote end, the RF receiver collects the data and converts it into equivalent voltage and sends it to the programmed ATMEGA328 at the receiver side which does the analogue to digital conversion (ADC conversion), and the digital signal is sent to the Liquid Crystal Display (LCD) for measurement display.

1.3 PROBLEM STATEMENT

The project aims at addressing the following problems

I. Measurement of bodies that are in motion is hectic.

II. Measuring in extreme environments is problematic e.g., environment with poisonous gases.

III. Remote non-assessable areas measurement isn’t easy.

1.4 PROJECT AIM

The aim of the project is to design and construct a device which will measure temperature of an object, and transmit the data wirelessly over a distance to a place where the data is needed to be viewed on a Liquid Crystal Display.

1.5 PROJECT OBJECTIVES

The objectives of this project are listed below

I. To sense/measure the temperature of an object.

II. To convert the temperature to an equivalent electrical signal.

III. To transmit the signal wirelessly to a receiver.

IV. To receive the signal wirelessly from the transmitter.

V. To convert the signal back to corresponding temperature values.

VI. To view the value on LCD.

1.6 METHODOLOGY

In order to achieve the objectives of the project work, the following steps will taken

I. Design of a suitable and practical circuit diagram, block diagram.

II. Learning how to program an embedded system using C language.

III. Develop the codes for the project work.

IV. Components and parts identification/specification/procurements.

V. Design and analysis of stages on breadboard.

VI. Development of Vero board layout diagram of circuit.

VII. Assembling and construction.

VIII. Test, analyse and diagnose fault in the circuit.

IX. Packaging of project.

X. Preparation and presentation of technical report.

1.7 THESIS OUTLINE

This project is comprised of five chapters and the outline for each chapter is listed below:

Chapter One: The introduction; it includes: The background and overview of the project work, project aim, project objectives, methodology and thesis outline of the project.

Chapter Two: Literature Review; it includes: Historical background and description of the components used.

Chapter Three: Design and Calculations; this chapter discusses the system design methodology, description of the project, circuit design and circuit analysis of the project.

Chapter Four: this chapter deals with construction process of the project. Both the hardware construction and software design implementation are treated here.

Chapter Five: this contains the conclusion and recommendation of the project.