Design and Construction of a 20-m Distance Remotely Controlled Metal Detector Using Arduino

   Abstract The project DESIGN AND CONSTRUCTION OF A 20-METRE DISTANCE REMOTELY  CONTROLLED METAL DETECTOR is used for detecting metallic objects such as phones,  bombs, and other metallic objects that are hidden from view. The design is based on the principle  of the Resonant Frequency Oscillator (RFO) metal detectors in which oscillation is a function of  parallel connection of an inductor and a capacitor operating in resonance. The project is divided  into two sections. The transmitter section acts as a remote control. This section has push buttons  and uses the microcontroller ATmega 328p for generating encoded signals which are transmitted  using radio frequency HC 12 transceiver module. At the receiver section, the HC 12 transceiver  module is used for receiving the RF signals sent from the transmitter. Another component of the  receiver section is the microcontroller ATmega 328p which is wired to the transceiver module for  decoding the signals received and hence for switching ON and OFF the metal detector circuit. The  metal detector circuit is a part of the receiver section. It is built using copper wires of gauge 26  according to the American Wire Gauge (AWG) standard and ceramic capacitor for producing  search field oscillation. The integrated circuit TDA 0161 is used together with the search field to  produce reference oscillation and it gives an output current of 10 mA when a metal is detected or  an output current of 1 mA when no metal is found by the search coil field. When a metal is detected  a buzzer emits an alarm. The complete circuit was tested and relevant parameters were measured.  When a metal is detected the detector sensor TDA 0161 output pin gives a value of 1.08 V;  however a value of 0.07 V is measured when no metal is detected. The range of operation of the  RF transceiver pair is found to be 900 metres. The project finds application in banks, shopping  malls and any security environment that requires the sensing of metallic objects.
TABLE OF CONTENTSCONTENTS PAGETITLE PAGE i DECLARATION iiCERTIFICATION iiiDEDICATION ivACKNOWLEDGEMENT vTABLE OF CONTENTS vi LIST OF TABLES viiiLIST OF FIGURES ixABSTRACT x1.0 INTRODUCTION 1.1 Background of the Study 1 1.2 Statement of the problem 21.3 Aim and Objectives of the Study 2 1.4 Significance of the Study 31.5 Scope of Study 32.0 LITERATURE REVIEW2.1 Theoretical Framework 4 2.2 Conceptual Framework 52.2.1 Development of block diagram 6 2.3 Review of Related Empirical studies 92.4 Summary of Literature Review 113.0 CIRCUIT ANALYSIS AND DESIGN3.1 Introduction 133.2 Circuit Analysis3.2.1 Analysis of power supply 133.2.2 Analysis of metal detector circuit 143.2.3 Analysis of transmitter circuit 193.2.4 Analysis of the receiver circuit 203.3 Overview of Microcontroller (ATmega 328p) 223.4 Flowchart 253.5 Programming 273.6 Simulation 273.7 Circuit Diagram 284.0 CONSTRUCTION, TESTING, RESULT, DISCUSSION4.1 Construction 294.1.1 Construction on bread board 294.1.2 Construction on vero board 314.2 Testing 334.3 Results 334.4 Discussion 335.0 CONCLUSION AND RECOMMENDATION5.1 Conclusion 355.2 Recommendation 35REFERENCES 36APPENDICES