DESIGN AND DEVELOPMENT OF A REAL TIME DATA ACQUISITION AND CONTROL SYSTEM

xii

Design and DeVELOPMENT oF A REAL TIME DATA ACQUISITION AND CONTROL SYSTEM

By

EMINA, ETOMI EDIRIN
U2011/3015544

And

FAKAYEJO, AJIBOLA RARHAEL
U2010/3015546

Department of Electrical/Electronic engineering
faculty of engineering
university of port hacourt
port hacourt, Nigeria.








march, 2015
university of port hacourt
faculty of engineering
Department of Electrical / Electronic engineering
final year projecct report
on
Design and DeVELOPMENT oF A REAL TIME DATA ACQUISITION AND CONTROL SYSTEM

By

EMINA, ETOMI EDIRIN
U2011/3015544

And

FAKAYEJO, AJIBOLA RARHAEL
U2010/3015546
submitted In Partial Fulfilment of the Requirement for the Award of the degree of Bachelor in engineering (b.eng) degree in Electrical / Electronic Engineering





March, 2015
DECLARATION
This is to declare that this project was carried out by Emina, Etomi Edirin and Fakayejo, Ajibola Raphael under the supervision of Dr. Vincent Nnebedum of the Department of Electrical / Electronic Engineering, University of Port Harcourt, 2011/2012 academic year, and that to the best of our knowledge, this project has not been carried out by any other persons.
Emina, Etomi Edirin
U2011/3015544 Signature Date

Fakayejo, Ajibola Raphael
U2010/3015546 Signature Date








CERTIFICATION
This is to certify that this project has been read and approved in partial fulfillment of the requirement for the award of Bachelor of Engineering (B.Eng) degree, Department of Electrical / Electronic Engineering.
Dr. Vincent Nnebedum
Project Supervisor Signature Date

Engr (Dr) Roland Uhunmwango
Head of Department Signature Date


External Examiner Signature Date







DEDICATION
This work is dedicated to the Almighty God who has been my source of inspiration and strength.














ACKNOWLEDGEMENT
This report would not have been a success without the support, advice, inspiration, encouragement and contributions from a number of people. We use this opportunity to express our sincere appreciation to everyone who supported us in one way or the other.
Our deep and profound gratitude goes to our Supervisor, Dr. Vincent Nnebedum for his advice, constructive criticism, suggestions and encouragement throughout the duration of this report.
We want to express deep thanks to our parents Mr & Mrs P. U. Emina and Mr & Mrs Fakayejo, and our siblings for their support.
We would love to record our deep gratitude to our friends such as Oregbheme Socrates and Nseobong Mfon Adiaden for their love, care, support, timely advice and immense contribution.
Also want to say thank you to all our Lecturers/Instructors who contributed immensely in making our studies successful.
Above all, we say a big thank you to God Almighty for His guidance, protection, provision and for making this work and program a success.



ABSTRACT
The Design and Development of a Real time Data Acquisition and Control system was used to monitor and control two processes, Temperature and Relative humidity in a process chamber made from heat treated wood having dimensions of 20×14×15 inches. By using a temperature and humidity transducer (LM35 and DHT11) interfaced to a Microcontroller (Arduino Uno) these process variables were captured, processed, displayed (on a 16×2 LCD screen and the DAQ PC GUI), and controlled so that the temperature and relative humidity remains constant within a set value selected through the DAQ PC GUI. The control of temperature and relative humidity was achieved by the microcontroller (Arduino Uno) through turning on or off a 1000 watts heater and a 4×4 inches cooling fan when the process variables reach their respective set points. A simplified version of C language was used for the microcontroller (Arduino Uno) programming. Emblematic to the real time DAQ and control system is the Data logging, which became possible by developing the DAQ GUI using VB.net, a high level language having a rich .NET framework library thus enabling the use of tools that facilitates serial communication between the developed DAQ GUI and the microcontroller via MAX232 level converter. The captured data were logged in a .csv (comma separate value) file format in Microsoft Excel, showing details such as; the temperature, relative humidity, temperature set point, relative humidity set point, day, date and time of logged data. With these logged data, analysis of the controlled variables were made using Microsoft Excel by plots showing variations of the process variable with its set points.











Title Page i
Declaration ii
Certification iii
Acknowledgement iv
Abstract vi
Table of Contents vii
List of Figures xi
List of Tables xii
CHAPTER 1 INTRODUCTION
Background to the Study 1
Statement of the Problem 3
Objective of the Study 3
1.4 Significance of the Study 3
1.5 Scope of the Study 4
CHAPTER 2 LITERATURE REVIEW
2.1 Temperature Measurement 5
2.2 Humidity Measurement 7
2.3 Data Acquisition System 9
2.5 Microcontroller (Arduino Uno) 11
2.6 Liquid Crystal Display 14
2.7 MAX232 16
2.8 VB.net and C programming 17
CHAPTER 3 METHODOLOGY
3.1 Processing Chamber 20
3.1.1 Transducers 21
3.2 Microcontroller (Arduino Uno Board) 21
3.3 16x2 Liquid Crystal Display 22
3.4 TTL/CMOS to RS232 logic converter (MAX232) 23
3.5 PC Data Acquisition and control system application software 24
3.6 Circuit Design 26
3.6.1 Design at Thermal Sensor 26
3.6.2 Design at the Humidity Sensor 27
3.6.2 Design of Power Supply Unit 28
3.6.3 Design of the Switching Unit 32
3.6.4 Design at the 16×2 LCD 38
3.7 Design at the MAX232 40
3.8 Algorithm 42
3.8.1 Algorithm for the data acquisition and control system 42
(Microcontroller)
3.8.2 Algorithm for VB.net program 44
3.9 Arduino Uno Program in c language for the Data Acquisition
and Control system 45
3.10 VB.net code for Data Acquisition and Control system 48
CHAPTER 4 TEST AND DISCUSSION OF RESULTS
4.1 Testing of the Real time Data Acquisition and Control System 51
4.1.1 Temperature test and Relative Humidity test 51
4.1.3 Data logger test 54
4.2 Discussion on the results obtained from the transducers 54
4.2.1 Using Microsoft Excel for data analysis 55
CHAPTER 5 CONCLUSION AND RECOMMENDATION
5.1 Recommendation 56
5.2 Conclusion 57
Reference 58
LIST OF APPENDICES
Appendix A: LM35 Data Sheet 59
Appendix B: DHT11 Humidity Sensor Data Sheet 62
Appendix C: Voltage Regulators (LM7805 and LM7812) Data Sheet 69
Appendix D: Diode (1N4007) Data Sheet 72
Appendix E: Heavy Duty Power Relay Data Sheet 73
Appendix F: Fan Data Sheet 74
Appendix G: Commercially Available Resistors and Capacitors 75
Appendix H: Transistor BC547 Data Sheet 76
Appendix I: 16×2 LCD Data Sheet 79
Appendix J: MAX232 Data Sheet 82
Appendix K: Sketch (C program) for the Microcontroller (Arduino Uno) 84
Appendix L: VB.net program for the DAQ GUI 103
LIST OF FIGURES
Figure 3.0: Block diagram of the Data Acquisition and Control System 25
Figure 3.1: Interfacing LM35 with Arduino Uno 27
Figure 3.2: Interfacing DHT11 with Arduino Uno 28
Figure 3.3: +12 VDC and +5 VDC Regulated Power Supply 29
Figure 3.4: Circuit Diagram of the Switching Unit 38
Figure 3.5: Interfacing 16×2 LCD with Arduino Uno 41
Figure 3.6: Interfacing the PC with an Arduino Uno 39
Figure 3.8: Circuit Diagram of a real time Data Acquisition and Control
System 41
Figure 4.1: Variation of temperature and relative humidity within the
process chamber 51
Figure 4.2: Graphical user interface of the real time data acquisition and 52
control system interface
LIST OF TABLES
Table 2.1: Hex code and function for 16×2 LCD 15
Table 4.1: Cost of Materials for Data Acquisition System 55