UNIVERSITY OF NAIROBI

FACULTY OF ENGINEERING

DEPARTMENT OF ELECTRICAL & INFORMATION ENGINEERING

MOBILE PHONE APPLICATION AND INTERFACE FOR A BAR CODE SCANNER

PROJECT INDEX: PRJ 025

PRESENTED BY

ACHIKI CORNELIUS MATONGO

F17/1752/2006

SUPERVISOR: DR. MWANGI MBUTHIA

EXAMINER: DR. G.S.O ODHIAMBO

PROJECT REPORT SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR

THE AWARD OF THE DEGREE

OF

BACHELOR OF SCIENCE IN ELECTRICAL AND ELECTRONIC ENGINEERING,

THE UNIVERSITY OF NAIROBI 2011

SUBMITTED ON: 18TH MAY 2011

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DEDICATION

I dedicate this project to my family and friends

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ACKNOWLEDGEMENTS

I would like to thank my family for the support they have offered to me while undertaking my studies

I would like to thank Dr. Mwangi Mbuthia, my supervisor for guiding me and providing necessary

support and ideas to aid in completion of this project.

I also appreciate the University of Nairobi, for creating a conducive environment for study and

research of this project.

I also express my gratitude to Muciiri Brian Roy Wambugu, Benjamin Ng’aru Kariuki and all my

friends for all the incite they provided me with and their advice during the period of doing the project.

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DECLARATION AND CERTIFICATION

This is my original work and has not been presented for a degree award in this or any other university.

………………………………………..

ACHIKI CORNELIUS MATONGO

F17/1752/2006

This report has been submitted to the Department of Electrical and Information Engineering, The

University of Nairobi with my approval as supervisor:

………………………………

Dr. MWANGI MBUTHIA

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TABLE OF CONTENTS DEDICATION ..................................................................................................................................... ii ACKNOWLEDGEMENTS ................................................................................................................ iii DECLARATION AND CERTIFICATION .......................................................................................... iv ABSTRACT ..................................................................................................................................... viii 1 CHAPTER 1 ................................................................................................................................ 1

1.1 PROBLEM DEFINITION ....................................................................................... 1 1.2 OBJECTIVES ....................................................................................................... 1 1.3 PROJECT SCOPE ................................................................................................. 1

2 CHAPTER 2 ............................................................................................................................... 2 2.1 LITERATURE REVIEW ........................................................................................ 2

2.1.1 HISTORY OF ANDROID .................................................................................. 2 2.1.2 BARCODES .................................................................................................... 4 2.1.3 SYMBOLOGY ................................................................................................ 5

2.1.3.1 Discrete .................................................................................................... 6 2.1.3.2 Continuous ................................................................................................ 6

2.1.4 UPC ............................................................................................................... 7 2.1.4.1 UPC-version A .......................................................................................... 7

2.1.4.1.1 Calculating the Checksum......................................................................... 9 2.1.4.1.2 2-Digit Supplemental Codes for Periodicals ................................................. 9

2.1.4.2 UPC-version E ........................................................................................ 10 2.1.5 EAN ............................................................................................................. 11

2.1.5.1 EAN-13 .................................................................................................. 11 2.1.5.2 EAN-8 .................................................................................................... 12 2.1.5.3 PARITY ENCODING TABLE ..................................................................... 13 2.1.5.4 EAN CHARACTER SET ENCODING TABLE .............................................. 14

2.1.6 CODE 39 ...................................................................................................... 15 3 CHAPTER 3 .............................................................................................................................. 16

3.1 DESIGN AND IMPLEMENTATION ...................................................................... 16 3.2 THE USB IN BRIEF ............................................................................................ 16 3.3 USB IN MOBILE PHONES .................................................................................. 16 3.4 IMPLEMENTATION ........................................................................................... 17

3.4.1 DATABASE IMPLEMENTATION .................................................................... 17 3.4.1.1 PREVIEW OF SQLITE .............................................................................. 17

3.4.2 BARCODE IMPLEMENTATION...................................................................... 18 3.4.2.1 ENCODING OF THE BARCODE ............................................................... 18 3.4.2.2 DESIGNING THE DATABASE ................................................................... 21

3.4.2.2.1 Program algorithm ................................................................................ 22 4 CHAPTER 4 .............................................................................................................................. 24

4.1 RESULTS AND ANALYSIS .................................................................................. 24 5 CHAPTER 5 .............................................................................................................................. 27

5.1 CONCLUSION ................................................................................................... 27 5.2 FUTURE WORK................................................................................................. 27

REFERENCES .................................................................................................................................. 28

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6 APPENDIX ................................................................................................................................ 29

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LIST OF FIGURES Figure 2.1 Android System Architecture ............................................................................................... 3 Figure 2.2 UPC barcode ....................................................................................................................... 7 Figure 2.3 UPC-A Barcode................................................................................................................... 8 Figure 2.4 UPC-E Barcode ................................................................................................................. 10 Figure 2.5 EAN-13 Barcode ................................................................................................................ 11 Figure 2.6 EAN-8 Barcode ................................................................................................................. 13 Figure 2.7 Code 39 Symbol ................................................................................................................ 15 Figure 3.1 Check Digit Computation Flow Chart................................................................................ 20 Figure 3.2 Flow Diagram of The Scanning Process ............................................................................ 21 Figure 4.1 Initial Screen ..................................................................................................................... 24 Figure 4.2Barcode Scanner View ....................................................................................................... 24 Figure 4.3 Displayed image an d name ............................................................................................... 25

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ABSTRACT

With the advancement in microprocessor technology, mobile phones are becoming more preferable in

our day to day lives as compared to personal computers since most phones are capable of

functionalities as sophisticated as our PC’s or laptops. Mobile phones nowadays have processor speeds

as high as 1Ghz and can have a storage capacity of about 32Gb and they also have long hours of battery

life.

In addition to these feature there is the aspect of great portability. When all this are combined into one,

the mobile phones can be viewed as a very powerful device that rival PC’s.

Hardware advancements also have made mobiles phones smaller and more efficient while including an

increasing number of peripherals.

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1 CHAPTER 1

1.1 PROBLEM DEFINITION

A mobile phone and a barcode scanner are to be interfaced such that a mobile phone application is to be

created and also an interface that will receive input from a barcode scanner and display item details

retrieved from a central database.

1.2 OBJECTIVES The study was aimed to achieve the following:

1. To develop a mobile application based on the android platform.

2. To develop a suitable means for the communication between the mobile phone and the barcode

scanner.

3. To develop a central database from which item details can be retrieved.

4. To understand the differences between a DTE (Data Terminal Equipment) and a DCE(Data

Communication Equipment).

5. To study and understand how the barcode system works including the basic principles of

operation of a barcode scanner.

1.3 PROJECT SCOPE The scope of this project is basically to make a mobile application and how to interface the mobile

phone to the scanner. The mobile application is to be developed in the Linux-based Android platform.

An algorithm based on the operation principles is also to be developed during the course of the project.

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2 CHAPTER 2

2.1 LITERATURE REVIEW

2.1.1 HISTORY OF ANDROID

In 2007, a group of handset manufacturers, wireless carriers, and software developers (notably, Google)

formed the Open Handset Alliance, with the goal of developing the next generation of wireless

platform. Unlike existing platforms, this new platform would be nonproprietary and based on open

standards, which would lead to lower development costs and increased profits. Mobile software

developers would also have unprecedented access to the handset features, allowing for greater

innovation.

There are already many mobile platforms on the market today, including Symbian, iOS, Windows

Mobile, BlackBerry, Java Mobile Edition (JME) but Android is the first complete, open, and free

mobile platform that was created by Google and the Open Handset Alliance(OHA). The other

platforms offer some access to the device hardware, but require writing complex C/C++ code and

making heavy use of proprietary APIs that are difficult to use. These proprietary operating systems that

often prioritize native applications over those created by third parties and restrict communication

among applications and native phone data.[1]

Android is built on top of a solid and proven linux kernel foundation. Linux provides the hardware

abstraction layer for Android, allowing Android to be ported to a wide variety of platforms in the

future. Internally, Android uses Linux for its memory management, process management, networking,

and other operating system services.

Android is designed not only for mobile phones but also for other hardware platforms.

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Android System Architecture.

Figure 2.1 Android System Architecture

• Linux Kernel

Core services (including hardware drivers, process and memory management, security, network, and

power management) are handled by a Linux 2.6 kernel. The kernel also provides an abstraction layer

between the hardware and the remainder of the stack.[3]

• Libraries

Running on top of the kernel, Android includes various C/C++ core libraries such as libc and SSL, as

well as:

a. Surface manager:-manages display

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b. Media codecs

c. SQL database

d. 2D and 3D graphics

e. Browser engine:-android uses the WebKit library.

• Android Runtime

This includes the Dalvik Virtual Machine and the core Java Libraries. Rather than use a traditional Java

virtual machine (VM) such as Java ME (Java Mobile Edition), Android uses its own custom VM

designed to ensure that multiple instances run efficiently on a single device.

The Dalvik VM executes Dalvik executable files, a format optimized to ensure minimal memory use.

• Android Framework

Android Application framework is a high-level layer to provide a developer with a space for a new

android applications development.

The main parts of the android framework are;

i. Activity Manager: This manages the life cycle of an activity

ii. Content Providers: This is the data that needs to be shared with other

applications in the phone.

iii. Resource Manager: This managers any part/resource that is not code.

iv. Notification Manager.

2.1.2 BARCODES Bar codes provide a simple and inexpensive method of encoding text information that is easily read by

inexpensive electronic readers. Bar coding also allows data to be collected rapidly and with extreme

accuracy.

Bar codes are usually made up of black bars and white bars in alternating sequence. The widths of

these black and white bars usually add up to a fixed width for all characters. This allows the complete

code to be scanned at any velocity within reasonable limits, because the timed widths of each bar can

be expressed as a fraction of the time to scan a complete digit. These fractions are relatively

independent of velocity provided the scan velocity does not change significantly in the course of a

scan.

Barcodes were originally developed and used in the US in the 1960’s by the railroad companies to

automatically identify their train wagons. In the early 1970s, common barcodes started appearing on

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grocery shelves. To automate the process of identifying grocery items, UPC barcodes were placed on

products.

Barcode system is almost a universal phenomenon when it comes to retail industry operations or any

other business where inventory management, employee record maintenance, asset tracking, etc are

automated using barcode technology.

This usually increases productivity and also reduces human error.

Some of the common uses of barcodes

1. Article numbering in supermarkets and other retailing operations.

2. Tracking of items in transit

3. Employee record maintenance

4. Patient identification

5. Library systems

6. Ticketing in sport centers, transport centers, entertainment joints etc.

7. Encoding of website URLs

8. Postal barcodes

Barcodes still remain the most reliable, inexpensive and easy to implement system of identification.

When compared to younger more functional auto ID technology such as RFID, there is a huge

difference in the hardware acquisition cost. A barcode is cheaper to generate since you can generate it

using pretty much any printer on the market and it can be read by cheap equipment. Most mobile

Enterprise phones these days can read barcodes simply using the built in camera along with a simple

piece of software.

RFID on the other hand, costs a lot more on average putting its fantastic functionality out of reach of

many projects for the time being.

2.1.3 SYMBOLOGY A bar code symbol is a parallel arrangement of varying width bars and spaces. Symbology is the term

used to describe the unambiguous rules specifying the way that data is encoded into the bar and space

widths. Each type of symbology (or barcode type) is a standard that defines the printed symbol and

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how a device, such as a barcode scanner, reads and decodes the printed symbol.

The specification of a symbology includes the encoding of the single digits/characters of the message

as well as the start and stop markers into bars and space, the size of the quiet zone required to be before

and after the barcode as well as the computation of a checksum.

Bar code symbologies can be categorized into two;

a. Discrete

b. Continuous

2.1.3.1 Discrete

Here each character can stand alone and can be decoded independently from the adjacent characters.

Each character is separated from its neighbor by loosely intercharacter gaps, which contain no

information. Every character has a bar on each end. In the decoding process, each character is treated

individually. Discrete barcodes make each character easier to find, but take up more space to print as

well. Discrete barcodes have higher tolerance for low print quality.

2.1.3.2 Continuous

The continuous barcode has no intercharacter gaps. Every character starts with a bar and ends with a

space or vice versa. Because of lack of intercharacter gaps, a continuous code requires less symbol

length to encode a given amount of data. Offsetting this density advantage is the fact that the range of

available demand printing technologies is more restricted for continuous codes than it is for discrete

codes.

Classification on Barcode Symbologies

1. Retail barcodes

These include; UPC-A, UPC-E, EAN-8 and EAN-13

2. Alpha-Numeric barcodes

These include; Code39,Code 93and Code 128

3. 2-Dimensional barcodes

Include; PDF417,Data Matrix, Code 49 and Maxicode.

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2.1.4 UPC UPC stands for Universal Product Code which is an American format for article numbering. A UPC

barcode contains 8 or 10 digits.

Figure 2.2 UPC barcode

Figure 2.2 shows a general structure of a UPC barcode. As we can see, the numbers below the barcode

are 811138000202. The digit 8 is the number-system character, the next five digits 11138 represent the

manufacturer’s number, the next five digits represent the product number and finally the last digit on

the right hand side of the barcode represents the check digit. The number-system character identifies

the symbol version and also the type of article. The check digit is used to detect errors. The check digit

and number-system character are not printed underneath the symbol.

The Universal Product Code (UPC) has been successfully employed in the supermarket industry since

1973.

There are two types of UPC barcodes namely;

a. UPC version A (UPC-A)

b. UPC version E (UPC-E)

UPC-A encodes 12-digits and is usually used for marketing products while UPC-E encodes 6-digits and

are usually associated with small packages.

2.1.4.1 UPC-version A

A typical UPC Version A symbol consists of two halves representing a total of 12 numeric digits. The

two six-digit halves are surrounded by left, centre and right guard patterns. The various guard bars can

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be thought of as start/stop patterns. The left half uses the odd parity encodations of digits, and the right

half uses the even parity encodations of digits.

Figure 2.3 UPC-A Barcode

As mentioned earlier the first numeric digit specifies the UPC number system digit. Here are some of

the various digits used for different specifications of products.

• 0- regular UPC codes

• 1- reserved

• 2- random weight items marked at the store

• 3- National Drug Code and National Health Related Items code

• 4- no format restrictions, for in-store use on non-food items

• 5- for use on coupons

• 6- reserved

• 7- regular UPC codes

• 8- reserved

• 9-reserved

The next group of 5 digits identifies the manufacturer (the manufacturer’s code). This number is

assigned by the Uniform Code Council (UCC). The first five digits of the right half of the pattern are

the product code digits and are assigned by the manufacturer, and the final digit is a Modulo 10

checksum check digit used for error detection. The check digit whose value is evaluated

mathematically based on all of the other numbers encoded in the symbol. A weighting scheme is used

in its calculation, so that the check digit also protects against transposition errors if the data is manually

entered. Although UPC is a continuous symbology the left and right halves of the pattern can be

independently decoded.

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2.1.4.1.1 Calculating the Checksum The checksum is a Modulo 10 calculation.

1. Add the values of the digits in positions 1, 3, 5, 7, 9, and 11.

2. Multiply this result by 3.

3. Add the values of the digits in positions 2, 4, 6, 8, and 10.

4. Sum the results of steps 2 and 3.

5. The check character is the smallest number which, when added to the result in step 4, produces

a multiple of 10.

Using the UPC code in figure 2.3 to calculate the checksum

Barcode data=12345678910

1. 1+3+5+7+9+0=25

2. 25*3=75

3. 2+4+6+8+1=21

4. 75+21=96

5. 96+X=100 therefore the check digit X=4

2.1.4.1.2 2-Digit Supplemental Codes for Periodicals

A UPC-A code may be augmented with a 2-digit or 5-digit extension. These extensions are handled as

separate barcodes and are generally used to create ISBN's (International Standard Book Numbers).

These extra digits are primarily used on periodicals and books.Weekly publications are generally

numbered 1-52, while semi-monthlies are numbered 1-24 and monthlies 1-12.

Because the bar height of either half of a UPC Version A symbol is greater than the width of the six

digits, omnidirectional scanning is possible if orthogonal scanning lines are employed. The scanner can

independently decode the right and left halves of the symbol because an examination of the data's

parity indicates which half was decoded. The guard bars are usually printed with greater length than

other bars in the symbol. This is done to maximize the allowable scanning tilt angle.

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2.1.4.2 UPC-version E

The UPC-E barcode is the short form representation of a UPC number. It reduces the data length from

12 digits to 6 digits by compressing the extra zeros. By suppressing zeroes, UPC-E codes can be

printed in a very small space and hence they are suited for identifying products in small packages. A

UPC-E barcode has 6 digits with an implied number system 0.

Figure 2.4 UPC-E Barcode

In addition to the requirement that the first digit of the barcode (number system) must be zero, there are

four rules that determine what UPC codes can be printed using the compressed UPC-E format:

1. If the last 3 digits of the manufacturer's number are 000, 100, or 200, the valid product code

numbers are 00000 - 00999 (1,000 numbers).

2. If the last 3 digits of the manufacturer's number are 300, 400, 500, 600, 700, 800, or 900, the

valid product code numbers are 00000 - 00099 (100 numbers).

3. If the last 2 digits in the manufacturer's number are 10, 20, 30, 40, 50, 60, 70, 80, or 90, the

valid product code numbers are 00000 - 00009 (10 numbers).

4. If the manufacturer's number does not end in zero, the valid product code numbers are 00005 -

00009 (5 numbers).

Like the UPC-A the UPC-E also has two versions, one can be augmented with a 2 digit supplement and

the other with a 5 digit supplement to the right of the barcode to increase the amount of information

encoded.

The six digits are enclosed between two left-hand guard bars and three right hand guard bars. A symbol

check character is encoded into the parity of the six data digits. Of the six digits, three have even parity

and three have odd parity

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2.1.5 EAN

EAN stands for the European Article Numbering and is a superset of UPC. This means that any

software or hardware capable of reading an EAN symbol will automatically be able to read an UPC

symbol. The only difference between EAN and UPC-A is that the number system code in UPC is a

single digit from 0 through 9 whereas an EAN number system code consists of two digits ranging from

00 through 99, which is essentially a country code. Each country has a numbering authority which

assigns manufacturer codes to companies within its jurisdiction. The manufacturer code is still five

digits long, as is the product code, and the check digit is calculated in exactly the same way.

EAN has two versions i.e EAN-13 which encodes 13 digits and EAN-8 which encodes 8 digits

2.1.5.1 EAN-13 EAN-13 is used world-wide for marking retail goods. The only difference between a UPC-A symbol

and an EAN-13 symbol is that the number system code is 2-digits long in EAN-13 as opposed to 1 digit

in UPC-A. Visually, the human-readable check digit is placed below the bar code instead of to the right

of it, but this does not make any difference, technically speaking, regarding the encoding itself.

Figure 2.5 EAN-13 Barcode

Just like a UPC-A the EAN-13 bar code is divided into four areas:

1. The number system,

2. The manufacturer code

3. The product code

4. The check digit.

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Normally the first number system digit is printed just to the left of the bar code, the second number

system digit is printed as the first character of the group of six numbers on the left-hand side below the

bar code, the manufacturer code is the next five digits on the left-hand side below the bar code, the

product code product code is the first five digits on the right-hand side below the bar code, and the

check digit is the last digit on the right-hand side below the bar code.

Before an EAN-13 symbol may be encoded, the software must compute the correct checksum digit

which will be appended to the bar code. The checksum digit is based on a modulo 10 calculation based

on the weighted sum of the values of each of the digits in the number system, manufacturer code, and

product code.

The steps for calculating the check digit are as follows:

1. Consider the right-most digit of the message to be in an "odd" position, and assign odd/even to

each character moving from right to left.

2. Sum the digits in all odd positions, and multiply the result by 3.

3. Sum the digits in all even positions.

4. Sum the totals calculated in steps 2 and 3.

5. The check digit is the number which, when added to the totals calculated in step 4, result in a

number evenly divisible by 10.

6. If the sum calculated in step 4 is evenly divisible by 10, the check digit is "0" (not 10).

2.1.5.2 EAN-8

EAN-8 is a shortened version of the EAN-13 code. An EAN-8 symbol has a left-hand guard pattern,

four odd parity digits, a centre guard pattern, four even parity digits, and a right-hand guard pattern. An

EAN-8 symbol encodes two flag digits (2-digit country code), five data digits, and one check digit.

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Figure 2.6 EAN-8 Barcode

UPC/EAN has proven to be extremely successful in the retail marketplace. In normal usage, every code

from a supermarket scanner is verified against an in store computer's database before being acted upon.

In this mode, very high data security has been reliably demonstrated.

2.1.5.3 PARITY ENCODING TABLE This table indicates the parity with which each character in the left-hand side of the bar code should be

encoded. The parity is based on the first digit of the EAN-13 value.

FIRST NUMBER

SYSTEM DIGIT PARITY TO ENCODE WITH

MANUFACTURER CODE

CHARACTERS

SECOND NUMBER SYSTEM

DIGIT

1 2 3 4 5

0(UPC-A) Odd Odd Odd Odd Odd Odd

1 Odd Odd Even Odd Even Even

2 Odd Odd Even Even Odd Even

3 Odd Odd Even Even Even Odd

4 Odd Even Odd Odd Even Even

5 Odd Even Even Odd Odd Even

6 Odd Even Even Even Odd Odd

7 Odd Even Odd Even Odd Even

8 Odd Even Odd Even Even Odd

9 Odd Even Even Odd Even Odd

Table 2.1 The Parity Encoding Table

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A UPC-A bar code always has a first number system digit of zero, and therefore uses exclusively odd

parity. In fact, any EAN-13 symbol which has a first number system digit of 0 is actually an UPC-A

symbol, not an EAN-13 symbol.

2.1.5.4 EAN CHARACTER SET ENCODING TABLE

This table indicates how to encode each digit of an EAN-13 bar code depending on which half (left or

right) of the bar code the digit is found in. In the case of a left-hand digit, the encoding (odd or even

parity) is based on the value of the first digit of the number system code

DIGIT LEFT HAND ENCODING RIGHT HAND

ENCODING ODD PARITY(A) EVEN PARITY(B)

0 0001101 0100111 1110010

1 0011001 0110011 1100110

2 0010011 0011011 1101100

3 0111101 0100001 1000010

4 0100011 0011101 1011100

5 0110001 0111001 1001110

6 0101111 0000101 1010000

7 0111011 0010001 1000100

8 0110111 0001001 1001000

9 0001011 0010111 1110100

Table 2.2 EAN CHARACTER SET ENCODING TABLE

The left hand encoding even parity is obtained as follows;

a. Changing all the zeros to ones and all the ones to zeroes in the odd parity column and then

reading them from right to left.

The right hand encoding is found by reading the left hand encoding parity in reverse.

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2.1.6 CODE 39

Code 39 was the first alphanumeric symbology to be developed. Code 39 is widely used in many

industries and is the standard for many government barcode specifications, including the U.S.

Department of Defense. Code 39 is defined in American National Standards Institute (ANSI) standard

It is a discrete, two widths, self checking, variable length symbology that can readily be printed by a

variety of technologies.

Every Code 39 character has five bars and four spaces. Of these nine elements, 3 are wide and 6 are

narrow.

A code 39 symbol comprises;

i. A leading quiet zone

ii. A start character

iii. Data characters

iv. Stop character

v. Trailing quiet zone

Figure 2.7 Code 39 Symbol

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3 CHAPTER 3

3.1 DESIGN AND IMPLEMENTATION

In the design, the android mobile phone is to be interfaced to the barcode scanner with the help of a

USB cable.

3.2 THE USB IN BRIEF

The USB was designed with the goal of being simple to use and low cost of implementation. The USB

was previously regarded as a high speed serial bus. Serial configuration was generally preferred as

compared to parallel configuration owing to cheap cables and easier mode of implementation.

The USB has the following features in relation to the PC;

a. Hot-pluggable:-I/O devices can be added to the PC while it is still running.

b. Easier to use:- The I/O devices is easily recognizable and the appropriate devices drivers

are configured automatically.

c. High Performance:-USB transfers at a rate of about 12Mbps which is much faster than

the existing serial and parallel ports.

d. Single connector type:-all devices are plugged into the same socket type

e. Power supplied by the cable:-most devices will not require extra external power source

to power them.

f. Power management:- the devices automatically turn off when not in use.

3.3 USB IN MOBILE PHONES

The mobile phone basically has to be converted into a host device so as to see the barcode scanner as a

peripheral and therefore the phone can retrieve whichever information the scanner acquires. The mobile

phone basically does not have enough power to drive the USB peripheral and thus an external source of

power for the USB would be required. Mobile phones with USB-host capabilities would be a major

milestone in the advancement in mobile technology since pretty much any device can be interfaced

with the mobile so long as it has a USB connector. Combining the extreme portability of the mobile

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phone and the versatility of the USB opens a wide range of applications.

The android platform also does not support USB-Host capabilities. Therefore, for the android phone to

support USB, drivers have to be written and patched to the Kernel of the phone. After this the android

kernel is then recompiled so as to integrate the USB drivers into the platform.

Some mobile phone manufactures have been able to add USB-host capabilities to their products for

example the Motorola DroidX, NEXUS 1 and Toshiba.

The possibilities for the interfacing of mobile phones and various peripherals are enormous and may

prove to be very useful in various fields.

For example a retailer might be able to request for more goods from a supplier by sending only the

codes of the goods he needs rather than writing a whole bunch of details relating to the goods he wants.

Since barcodes can be encoded with all the necessary information relating to a particular item. All the

retailer and the supplier need is a means to access a central database through the mobile phone and the

necessary services/orders are carried out.

Doctors may also be able to quickly reference a patient's details in a more efficient and fast way. This

can all be done if the mobile phone is able to access the records in a remote location.

3.4 IMPLEMENTATION In the implementation of the project, the Android SDK environment was used in the Eclipse platform.

For the creation of databases, SQLite was used.

3.4.1 DATABASE IMPLEMENTATION

3.4.1.1 PREVIEW OF SQLITE

SQLite is a relational database management system same as Oracle, IBM’s DB2 and Microsoft SQL

server. SQLite has a reputation of being extremely reliable and is the database system of choice for

many consumer electronic devices, including several MP3 players, the iPhone and the iPod Touch and

of course Android and Symbian phones.

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SQLite is commonly used because of these features;

a. It is Open-Source:-it is placed in the public domain.

b. It is lightweight and hence can be store within the memory allocation of the mobile phone;

c. It requires no setup or administration. There is no server, no config file and no need for a

database administrator unlike the standard SQL.

Lightweight and powerful, SQLite differs from many conventional database engines by using a loosely

typed approach to column definition. Rather than requiring column values to conform to a single type,

the values in each row for each column are individually typed. As a result, there’s no strict type

checking when assigning or extracting values from each column within a row.

3.4.2 BARCODE IMPLEMENTATION

For the mobile phone to be able to read and decode barcodes, a zXing(zebra crossing) library was used.

ZXing is an open-source, multi-format 1D/2D barcode image processing library implemented in Java.

It uses the built-in camera on mobile phones to photograph and decode barcodes on the device, without

communicating with a server.

ZXing supports several barcode formats i.e.; UPC-A and UPC-E, EAN-8 and EAN-13 ,Code 39 Code

93, Code 128 etc.

The zXing library can be called from within your application through an intent as shown;

Intent intent = new Intent("com.google.zxing.client.android.SCAN");

3.4.2.1 ENCODING OF THE BARCODE

The zXing library encodes the barcode by considering that a “1” represents a bar or a dark section and

a “0” represents a "light" or "space" section of the bar code.

A double dark section will be viewed as a 1 1 and a double space or light section will be viewed as a

00.

Before the scanner encodes the value of the barcode, the checksum digit is firstly calculated and if it is

valid, the code is scanned else an error is returned i.e. the barcode is viewed as an invalid code. Validity

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of the checksum digit is such that the check digit (i.e. last digit of the barcode) is cross-referenced with

the value computed by the barcode scanner application. Therefore the two values have to tally/match

for a valid barcode.

Note;

Guard bars are usually encoded as dark-light-dark sections or bar-space-bars which can be viewed as

101. This applies for all the guard bars i.e. Left, Center and Right guard bars

Steps for encoding/decoding the barcode

1. Compute the checksum for validity

2. Check the number system digit value and cross-reference the respective odd-even parity

sequence with the parity encoding table.

3. Encode each number with the corresponding 1 0 sequence using the character set encoding

table taking into account the respective parity of the characters whether even or odd parity.

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Compute the Checksum

Start

Is computed check digit equal to check digit on

the barcode?

Read the barcode and determine the encoded data on the code

NO

YES

Figure 3.1 Check Digit Computation Flow Chart

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3.4.2.2 DESIGNING THE DATABASE

Figure 3.2 Flow Diagram of The Scanning Process

Start

Load the Database

Open the Scan Application

Scan the Barcode

Close the DB

End

Is the item reference by barcode in

DB?

Continue?

Display Image of the item

YES

NO

Yes

NO

NO

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3.4.2.2.1 Program algorithm

The program follows the following steps during its implementation; a. The scanning application is first called into action via an intent.

b. The symbology and barcode format are determined and the check digit is then confirmed for validity of the code.

c. Scanning is then initiated. d. The database is then queried.

e. The program then cross-references the bar code scanned to the codes in the barcodeId field in the database.

f. If the barcode code is found in the database the corresponding image and details are displayed.

g. The program then exits.

The database will have four columns and can be represented as shown in the snippet below;

private static final String DATABASE_NAME = "barcode.db"; private static final int DATABASE_VERSION = 1; private static final String DATABASE_TABLE = "barcodes";

private static final String FIELD_ID = "_id"; private static final String BARCODE_ID = "BarcodesId"; private static final String PRODUCT_NAME = "Product"; private static final String PRODUCT_IMAGE = "Image";

private static final String DATABASE_CREATE = "create table barcodes (_id integer primary key autoincrement, "

+ "BarcodesId text not null, Product text not null, "

+ "Image_Path text not null);";

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After the creation of the database, the next step was to make the graphical user interface.

The GUI comprises of a scan button that is used to prompt for the opening of the barcode scanning

application. Firstly, the main layout is designed using XML (android uses XML for its graphical user

interface).

The button is then placed on the linear layout of the GUI and the button click functionality is the set as

follows.

scanButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub } });

The above code hooks up the Scan Button with the click functionality.

To navigate to the barcode scanning application we have to call the ZXing library via intents and

mentioned earlier.

Once the barcode has been detected and recorded, another function is performed to record the scanned

code on the main layout;

\ public void onActivityResult(int requestCode, int resultCode, Intent intent) { TextView tv1 = (TextView) findViewById(R.id.textView2); if (requestCode == 0) { if (resultCode == RESULT_OK) { contents = intent.getStringExtra("SCAN_RESULT"); format =

intent.getStringExtra("SCAN_RESULT_FORMAT");

TextView tv = (TextView) findViewById(R.id.textView2); tv.setText(contents);

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4 CHAPTER 4

4.1 RESULTS AND ANALYSIS

The following were the results that were observed when the application was run;

Figure 4.1 Initial Screen

Figure 4.2Barcode Scanner View

The default screen is as shown in figure 4.1 when the application is started. On clicking the “Scan

Barcode” button the view on figure 4.2 is shown. The red line is the one responsible for scanning the

barcode i.e the widths of the bars and spaces.

Once the barcode has been recognized and the value of the barcode determined, the product name and

the image of the product is displayed as shown in figure 4.3.

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Figure 4.3 Displayed image and name

26

Figure 4.4 Database created

The graphical User Interface of the database that is created after scanning the barcode is as displayed in

Figure4.5

At the first instance of the scan, the barcode number that is displayed in Figure 4.3 is

inserted/appended into the BarcodesId field. The corresponding product name is also displayed in the

product field. For the image field, the path to where the camera stored the captured product image is

referenced.

This shows how the application displays in the event that the barcode scanned is not found in the

database.

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5 CHAPTER 5

5.1 CONCLUSION

The main objective of the project was to interface the mobile phone to a barcode scanner. In the project

an alternative method of scanning was introduced. This is because the android platform is a new

technology and does not currently support USB-hosting capabilities and thus the need to use an

alternative way of scanning whatever barcode we have.

Using the mobile phone camera the project was a success since a barcode could be scanned and

eventually retrieved from a central database as in the objective.

5.2 FUTURE WORK

Mobile phones will certainly be able to go into USB-host mode in future. This is however dependent on

the fact that mobile phone manufactures enable their handset to accept USB-host capability software or

integrate USB-host functionality within their proprietary software.

Upon achieving this, interfacing of mobile phones to the numerous peripheral devices would be

possible and the scope application of this feature would then be enormous.

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REFERENCES [1] Reto Meier , “Professional Android Application Development”, Copyright © 2009 by Wiley

Publishing, Inc., Indianapolis, Indiana

[2] Dr. G.S.O Odhiambo, “Database Management and Knowledgebase Systems Class Lecture

Notes” ,Department of Electrical and Electronics Engineering, 23rd March 2007.

[3] Ed Burnet, “Hello Android”, Published by Pragmatic BookShelf, Copyright © 2008 Ed

Burnette.

[4] http://www.gs1kenya.org

[5] http://en.wikipedia.org/wiki/Barcode

[6] IDAutomation ,“Barcodes For Beginners” , Copyright © 2000-2007 IDAutomation.com, Inc

[7] http://developer.android.com

[8] John Hyde, “USB Design by Example: A Practical guide to Building I/O Devices”, Intel

University Press

[9] Bruce Eckel, “Thinking in Java” , 3rd Edition, Copyright © 2003 by Bruce Eckel, President,

Mind View, Inc Published by Pearson Education, Inc.

[10] http://code.google.com/p/zxing/wiki/DeveloperNotes

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6 APPENDIX

barcodeApp.java package com.achiki.barcodeapp; import android.app.Activity; import android.app.Dialog; import android.content.Intent; import android.database.Cursor; import android.hardware.Camera; import android.hardware.Camera.PictureCallback; import android.hardware.Camera.ShutterCallback; import android.os.Bundle; import android.widget.Button; import android.widget.EditText; import android.widget.ImageButton; import android.widget.TextView; import android.widget.Toast; import android.view.KeyEvent; import android.view.SurfaceView; import android.view.View; import android.view.View.OnClickListener; import android.view.View.OnKeyListener; public class barcodeApp extends Activity { /** Called when the activity is first created. */ String contents, format,p_duct; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button scanButton = (Button) findViewById(R.id.button1); TextView tv = (TextView) findViewById(R.id.textView1); ImageButton ib = (ImageButton) findViewById(R.id.imageButton1); SurfaceView surface = (SurfaceView) findViewById(R.id.surfaceView1); final EditText edittxt = (EditText) findViewById(R.id.editText1); // String uri = "/mnt/sdcard/DCIM/Camera/"; scanButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub Intent intent = new Intent( "com.google.zxing.client.android.SCAN"); intent.putExtra("SCAN_MODE", "ONE_D_MODE");

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startActivityForResult(intent, 0); TextView tv = (TextView) findViewById(R.id.textView2); tv.setText(contents); // d.setContentView(vs); // d.show(); } }); edittxt.setOnKeyListener(new OnKeyListener() { @Override public boolean onKey(View v, int keyCode, KeyEvent event) { // TODO Auto-generated method stub if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) { return true; } return false; } }); surface.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub Intent pictureIntent = new Intent( android.provider.MediaStore.ACTION_IMAGE_CAPTURE); startActivity(pictureIntent); } }); } public void onActivityResult(int requestCode, int resultCode, Intent intent) { TextView tv1 = (TextView) findViewById(R.id.textView2); tv1.setText("hello world"); if (requestCode == 0) { if (resultCode == RESULT_OK) { contents = intent.getStringExtra("SCAN_RESULT");

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format = intent.getStringExtra("SCAN_RESULT_FORMAT"); final EditText edittxt = (EditText) findViewById(R.id.editText1); final String strTxt= new String(edittxt.getText().toString()); System.out.print(edittxt.getText().toString());

TextView tv = (TextView) findViewById(R.id.textView2);

tv.setText(contents); DBAdapter db = new DBAdapter(this); db.open(); long rowID; rowID = db.insertRow(contents, strTxt, "Image_Path"); System.out.println("rowid = " + rowID); db.close(); } else if (resultCode == RESULT_CANCELED) { // Handle cancel TextView tv = (TextView) findViewById(R.id.textView2); tv.setText("cancelled"); } } } }

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DBAdapter.java package com.achiki.barcodeapp; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.database.sqlite.SQLiteStatement; import android.util.Log; import java.util.ArrayList; import java.util.List; public class DBAdapter { private static final String DATABASE_NAME = "barcode.db"; private static final int DATABASE_VERSION = 1; private static final String DATABASE_TABLE = "barcodes"; private static final String FIELD_ID = "_id"; private static final String BARCODE_ID = "BarcodesId"; private static final String PRODUCT_NAME = "Product"; private static final String PRODUCT_IMAGE_PATH = "Image_Path"; private static final String TAG = "DBAdapter"; private Context context; private SQLiteDatabase db; private DatabaseHelper dbHelper; private static final String DATABASE_CREATE = "create table barcodes (_id integer primary key autoincrement, " + "BarcodesId text not null, Product text not null, " + "Image_Path text not null);"; public DBAdapter(Context ctx) { this.context = ctx; dbHelper = new DatabaseHelper(context); } private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(DATABASE_CREATE); }

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@Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data");

db.execSQL("DROP TABLE IF EXISTS barcodes");

onCreate(db); } } // open the database public DBAdapter open() throws SQLException { db = dbHelper.getWritableDatabase(); return this; } // close the database public void close() { dbHelper.close(); } // insert a row public long insertRow(String BarcodesId, String Product, String Image_Path) {

ContentValues initialValues = new ContentValues();

initialValues.put(BARCODE_ID, BarcodesId);

initialValues.put(PRODUCT_NAME, Product); initialValues.put(PRODUCT_IMAGE_PATH, Image_Path); return db.insert(DATABASE_TABLE, null, initialValues); } // delete a row public boolean deleteRow(long rowId) { return db.delete(DATABASE_TABLE, FIELD_ID + "=" + rowId, null) > 0; } public Cursor getRow(long rowId) throws SQLException { Cursor cursor = db.query(true, DATABASE_TABLE, new String[] { FIELD_ID, BARCODE_ID, PRODUCT_NAME, PRODUCT_IMAGE_PATH }, FIELD_ID + + rowId, null, null, null, null, null);

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if (cursor != null) { cursor.moveToFirst(); } return cursor; }