INVESTIGATION OF THE PERFORMANCE OF RASPBERRY
PI TO DIGITIZE ANALOG SIGNAL WITH RESPECT TO 8-BIT
AND 12 BIT VERTICAL RESOLUTIONS
MUHAMMAD AMINRUL BIN NORSHAS NANAWAWI
INVESTIGATION OF THE PERFORMANCE OF RASPBERRY
PI TO DIGITIZE ANALOG SIGNAL WITH RESPECT TO 8-BIT
AND 12 BIT VERTICAL RESOLUTIONS
MUHAMMAD AMINRUL BIN NORSHAS NANAWAWI
This report is submitted in partial fulfilment of the requirements
for the degree of Bachelor of Electronic Engineering with Honours
Faculty of Electronic and Computer Engineering
Universiti Teknikal Malaysia Melaka
Tajuk Projek : Investigation of The Perfomance of Raspberry Pi To Digitize Analog Signal With Respect to 8-Bit and 12-Bit Vertical Resolution
Sesi Pengajian : 2017/2018
Saya MUHAMMAD AMINRUL BIN NORSHAS NANAWAWI mengaku membenarkan laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-syarat kegunaan seperti berikut:
1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.
2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja. 3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan
pertukaran antara institusi pengajian tinggi. 4. Sila tandakan ():
SULIT*
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972)
TERHAD* (Mengandungi maklumat terhad yang telah ditentukan oleh organisasi/badan di
mana penyelidikan dijalankan.
TIDAK TERHAD
Disahkan oleh:
(TANDATANGAN PENULIS) (COP DAN TANDATANGAN PENYELIA)
Alamat Tetap: No. A76 JLN Mentari A4, TMN Sinar Mentari, Bedong, Kedah
Tarikh : 25 May 2018 Tarikh : 25 May 2018
*CATATAN: Jika laporan ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali tempoh laporan ini perlu dikelaskan sebagai SULIT atau TERHAD.
UNIVERSITI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
DECLARATION
I declare that this report entitled “Investigation of The Perfomance of Raspberry Pi To Digitize Analog Signal With Respect to 8-Bit and 12-Bit Vertical Resolution” is the result of my own work except for quotes as cited in the references.
Signature : ………
Author : ………
APPROVAL
I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in terms of scope and quality for the award of Bachelor of Electronic Engineering with Honours.
Signature : ………
Supervisor Name : ………
DEDICATION
To my beloved parents, brothers and sister, thank you for your endless love and support, without them, I would be aimless.
To my lecturers and friends, guidance and knowledge we shared and discuss together till a sleepless night.
ABSTRACT
ii
ABSTRAK
iv
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
Declaration i
Approval i
Dedication i
Abstract i
Abstrak ii
Acknowledgements iv
Table of Contents v
List of Figures ix
List of Tables xiii
List of Symbols and Abbreviations xiv
List of Appendices xv
CHAPTER 1 INTRODUCTION 1
1.1 Background 1
1.2 Problem Statement 2
1.3 Objectives 4
vi
1.5 Thesis Structure 5
CHAPTER 2 BACKGROUND STUDY 7
2.1 Lightning 7
2.1.1 Thundercloud Formation 7
2.1.2 Thundercloud structure 8
2.1.3 Lightning Flash and Thunder 10
2.2 Electromagnetic Field Emitted by Lightning 10
2.2.1 The EM Field Produced 10
2.2.2 Ampere’s Law and Related Equations 11
2.2.3 Electromagnetic Fields Detected by Antenna 14
2.3 PicoScope (4224 Series) 15
2.4 Raspberry Pi 17
2.4.1 General Information of Raspberry Pi 17
2.4.2 Raspberry Pi Basic Components 21
2.4.3 System on Chip 25
2.5 BitScope Micro’s 31
2.5.1 Introduction 31
2.5.2 Virtual-Machine Architecture 33
2.5.3 Bitscope Schematics 35
2.6 Nyquist Theorem 40
2.7 Cross-correlation 41
CHAPTER 3 METHODOLOGY 43
3.1 Project Overflow 43
3.2 Raspberry Pi Setup 44
3.2.1 Raspberry Pi Operating System 44
3.2.2 Preparation of SD Card 45
3.3 BitScope Micro setup 49
3.4 Lab Session 52
3.5 Outdoor Measurement Research 59
3.6 MatLab Software 61
3.7 Flow chart 64
3.7.1 Flow Chart of Research Methodology 64
3.7.2 Flow Chart of Pi-Scope 65
3.7.3 Flow Chart of Coding 66
3.7.4 Flow Chart of Lab-Test 67
3.7.5 Flow Chart of Outdoor Measurement 68
CHAPTER 4 RESULTS AND DISCUSSION 69
4.1 Introduction 69
viii
4.2.1 Result for 8-bit resolution 71
4.2.2 Result for 12-bit resolution 74
4.2.3 Cross Correlation Analysis 75
4.3 Lightning Event 79
4.3.1 Result 80
4.3.2 Analysis 82
4.4 Discussion 92
CHAPTER 5 CONCLUSION AND FUTURE WORKS 94
5.1 Conclusion 94
5.2 Future Work 95
REFERENCES 96
List of Publications and Papers Present 99
APPENDIX A 100
LIST OF FIGURES
Figure 2.1: Formation of Thunderclouds [3]. 8
Figure 2.2: Distance of cloud in an idealized tripole charge structure of a thundercloud
[3]. 9
Figure 2.3: E-Field of a Dipole [1]. 11
Figure 2.4: A straight current channel of infinite length and B at a distance, r[1]. 12
Figure 2.5: Direction Flow of EM Field [1]. 13
Figure 2.6: Right Hand Grip Rule [1]. 13
Figure 2.7: Example of Outdoor Measurement. 14
Figure 2.8: PicoScope 4224 series [4]. 16
Figure 2.9: Raspberry Pi 2 model B. 18
Figure 2.10: Raspberry Pi 3 model B. 18
Figure 2.11: Raspberry Pi’s released models [7]. 19
Figure 2.12: PiTFT [7]. 22
Figure 2.13: System block diagram of ARM Cortex-A7 [8]. 25 Figure 2.14: GPU graphics pipeline of Raspberry Pi’s [6]. 27
Figure 2.15: Bitscope Micro [18]. 32
x
Figure 2.19: Analog capture the ADC buffer, and ADC [20]. 38
Figure 2.20: Input Channel Buffers [20]. 38
Figure 2.21: BitScope input ranges for an ADC [18]. 39
Figure 2.22: BNC connectors [18]. 39
Figure 3.1: Raspberry Pi’s device connection [6]. 47
Figure 3.2: Bitcope block diagram [20]. 50
Figure 3.3: First step, open download file. 51
Figure 3.4: dpkg Bitscope Library. 51
Figure 3.5: Run python coding. 51
Figure 3.6: BitScope channels test. 52
Figure 3.7: BitScope verification. 52
Figure 3.8: Lab session set-up. 53
Figure 3.9: Set up the PicoScope. 54
Figure 3.10: To save the signal data. 55
Figure 3.11: To save the signal data. 55
Figure 3.12: To save the signal data. 56
Figure 3.13: Setting Pi-Scope. 56
Figure 3.14: DSO configuration. 57
Figure 3.15: Pi-Scope interface. 57
Figure 3.16: Sketch of outdoor measurement 60
Figure 3.17:Bitscope and PicoScope in Outdoor Measurement. 60 Figure 3.18:Antenna that used to captured lightning. 61
Figure 3.20: Positive NBE lightning signal. 63
Figure 3.21: Waveform produce after overlap. 63
Figure 3.22: Result after applied cross-correlation. 63
Figure 4.1: Signal of 300 kHz. 72
Figure 4.2: Number of samples for each frequency. 73
Figure 4.3: Signal of 100 kHz. 74
Figure 4.4: Number of samples for each frequency. 75
Figure 4.5:The overlap of signal 100 kHz. 76
Figure 4.6:The overlap signal of 100 kHz. 76
Figure 4.7:Result of cross-correlation of 100 kHz. 76
Figure 4.8: Number of frequency with lag 0. 79
Figure 4.9: Negative return stroke lightning signal. 80
Figure 4.10: Positive NBE lightning signal. 81
Figure 4.11: Negative NBE lightning signal. 81
Figure 4.12: Number of lag in lightning event 83
Figure 4.13: Result before cut in a few number of sample. 84 Figure 4.14: Result after cut in a few number of sample. 84 Figure 4.15: Result of cross-correlation before adjustment. 85 Figure 4.16: Result of cross-correlation after adjustment. 85
Figure 4.17: Cross-correlation result of 200 kHz. 88
xii
Figure 4.21: Cross-correlation result of 700 kHz. 90
Figure 4.22: Cross-correlation result 800 kHz. 90
Figure 4.23: Cross-correlation result 900 kHz. 91
Figure 4.24: Cross-correlation result 1 MHz. 91
LIST OF TABLES
Table 1: Specifications of PicoScope 4224 series [4]. 16 Table 2: Major features of the Raspberry Pi models [7]. 21
Table 3: Specification Micro specification [18]. 32
Table 4: Raspbian directory structure [6]. 45
Table 5: Time base for each frequency. 58
Table 6: Frequency injected to the PicoScope and Pi-scope. 71
Table 7: Number of sample and frequency sample. 72
Table 8: Number of sample and frequency sample. 75
Table 9: Number of frequency with lag -1, 0 and 1. 77
Table 10: Number of frequency with lag 0. 78
Table 11: Lag of signal lightning. 82
Table 12: Number of sample before adjustment. 86
xiv
LIST OF SYMBOLS AND ABBREVIATIONS
For examples:
-CG : Negative cloud-to-ground flash +CG : Positive cloud-to-ground flash +NBE : Positive Narrow-bipolar Event -NBE : Negative Narrow-bipolar Event E-Field : Electric Field
B-Field : Magnetic Field I/O : Input/output
GPU : Graphic Processing Unit CPU : Central Processing Unit RAM : Random Access Memory GPIO : General-purpose input/output SD : Secure Digital
ARM : Advanced RISC Machines USB : Universal Serial Bus STB : set-top box
LIST OF APPENDICES
CHAPTER 1
INTRODUCTION
1.1 Background
Lightning flash is one of the world fascinating wonders. Despite of preserved records of the naked eyes observations of lightning flashes in ancient scriptures, until now we don’t understand the fundamental mechanism of lightning flashes.
Generally, there are 3 types of lightning flashes based on movement and direction of electrical charges namely positive ground flash (+CG), negative cloud-to-ground (-CG) and Cloud Flash (CF). For Cloud Flash, it can further be divided into two subtypes which are narrow bipolar event (NBE) flash and intra-cloud (IC) flash.
An oscilloscope is a laboratory instrument that has been used to capture and collect the waveforms of lightning that has been sensed by the antenna where is the antenna is directly or through filter circuits connected to the oscilloscope. This device draws a graph of the instantaneous signal voltage as a function of time. Usually oscilloscope displays alternating current (AC) or direct current (DC) waveforms. It has frequency as low as 1 HZ or as high as several Megahertz (MHz) and the display is divided into horizontal and vertical divisions.
1.2 Problem Statement
3
1) The oscilloscope in laboratory is heavy, it is difficult for the researcher to bring the oscilloscope for outdoor research.
2) This item also is not portable, they need ac supply to power up the oscilloscope. Without the ac supply oscilloscope cannot functioning.
3) The third problem is, oscilloscope is very expensive such as Yokogawa, Tektronik, and Keysight. They will become more expensive when the resolution is higher.
Therefore, a significant question should be asked, can we design low-cost oscilloscope that portable, adjustable and stand-alone but producing same quality with the current oscilloscope?
