barcode scanner seminar report

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    ASSIGNMENT ON WIRELESS BARCODE SCANNER

    Visvesvaraya Technological University, Belgaum

    K.L.E Societys

    B. V. Bhoomaraddi College of Engineering & Technology

    Hubli-580031

    Department of Electrical & Electronics Engineering

    Project title

    ASSIGNMENT

    WIRELESS BARCODE SCANNER

    Report submitted by

    Sindhu Bijjal - 2BV08EE048

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    ASSIGNMENT ON WIRELESS BARCODE SCANNER

    WHAT IS A BARCODE SCANNER?

    A barcode scanner (which may also be referred to as a barcode reader) is a piece of electronic

    equipment that can read printed barcodes. Barcodes are used to manage and track a wide variety of

    items, ranging from grocery store items to cars to insects such as bees. A barcode scanner uses a lens,

    light source and photo conductor to translate optical impulses to electrical impulses.

    BASIC KINDS OF BARCODE SCANNERS

    There are many kinds of barcode scanners based on different technologies. Few examples are -

    1) PEN-SCANNER- pen wand is the simplest barcode reader. however, because it has to remain in

    direct contact with the bar code, must be held at a certain angle, and has to be moved over the

    bar code at a certain speed.

    2) A SLOT SCANNER- remains stationary and the item with the bar code on it is pulled by hand

    through the slot. Slot scanners are typically used to scan bar codes on identification cards. 3) A CCD SCANNER

    4) AN IMAGE SCANNER: also called a camera reader, uses a small video camera to capture animage of the bar code and then uses sophisticated digital image processing techniques to decode

    the bar code

    5) A LASER SCANNER: either hand-held or stationary an easily read a bar code up to 24 inchesaway. To reduce the possibility of errors, a laser scanning may perform up to 500 scans per

    second.

    6) BLUETOOTH-SCANNER: it uses bluerooth technology to sacn the data. But Bluetooth has a

    lesser range than the other wireless technologies.

    The barcode scanners can be either-

    Attached to computer with a wire

    Can be wireless

    WIRELESS BARCODE SCANNER

    Wireless barcode scanner also known as RF scanner or cordless

    scanner operates on wireless frequencies like a cordless

    phone. Wireless scanner transmits scanned data to a base

    station which is connected to a processor. Wireless barcode

    scanners models vary by transmission distance and battery life.

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    ASSIGNMENT ON WIRELESS BARCODE SCANNER

    UNDERSTANDING BARCODING TECHNOLOGY

    WHAT ARE BARCODES?

    A barcode is an optical machine-readable representation of data, which shows data about the object to

    which it attaches. originally barcodes represented data by varying the widths and spacings of parallel

    lines. The barcodes can be represented data by varying the widths and spacings of parallel lines (1D) or

    into rectangles, dots, hexagons and other geometric patterns (2D).

    Fig 2: samples of 1D and 2D barcodes

    http://en.wikipedia.org/wiki/Machine-readable_mediumhttp://en.wikipedia.org/wiki/Rectanglehttp://en.wikipedia.org/wiki/Dothttp://en.wikipedia.org/wiki/Hexagonhttp://en.wikipedia.org/wiki/Hexagonhttp://en.wikipedia.org/wiki/Dothttp://en.wikipedia.org/wiki/Rectanglehttp://en.wikipedia.org/wiki/Machine-readable_medium
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    ASSIGNMENT ON WIRELESS BARCODE SCANNER

    RETRIEVE INFORMATION FROM BARCODES

    There are many types of commercial barcode standardS. HERE Code 3 of 9, or Code 39 is been

    explained indetail

    1) Each Code 39 character consists of 5 black stripes sandwiching 4 white spaces.

    2) Black stripes, as well as white spaces can be both thin and thick.

    3) Code 39s encoding scheme is therefore binary, with thick stripes/spaces representing 1s and

    thin stripes/spaces representing 0s (shades of the stripes/spaces do not matter since black and

    white simply allows us to differentiate the thickness of stripes/spaces).

    4) The following table shows all the available encodings in Code 39.

    Fig 2: the representations of the codes of barcode coded as given by39.

    For example, the English alphabet, K would correspond to the binary code of length 9: 100000011

    (scanning from left to right according to thickness).

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    ASSIGNMENT ON WIRELESS BARCODE SCANNER

    HARDWARE BLOCK DIAGRAM OF A WIRELESS BARCODE SCANNER

    fig 3: block diagram of a complete wireless barcode scanner

    Sensor:

    Sensor is something which acts as Connectionbetween external world and

    internal complex digital circuitry. The scanner reads data by illuminating a section of the bar

    code. This is usually done by laser light. light with the photodetector, which is an analog

    signal. This analog signal can then be amplified and conditioned, and optionally converted

    to digital format using an ADC before being passed to the decoder.

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    ASSIGNMENT ON WIRELESS BARCODE SCANNER

    Micro-computer:

    This is important part of barcode scanner which may contain a Digital Signal

    Processor (DSP) or normal Processor. The main function of this micro-computer is to

    understand and interpret what actually sensor read. It is programmable, usually by scanning

    bar coded programming commands into the system from a special programming menu

    included in the system

    Battery and Charging Unit:

    This is essential only is barcode reader is a cordless device. It mainly consists of a

    charging unit and a lithium ion/lithium polymer battery. In case of above example (that is

    Motorola scanner) 5V, 620mA battery is used. More importantly battery should be light,

    powerful and should have higher life cycles.

    Flash Memory

    Read/Writeable RAM (a.k.a. Non-Volatile RAM)

    This is a type of Random Access Memory chip that does not lose its contents when its power is

    turned off; however, it can be intentionally written to, read from, and intentionally erased. It

    is a type of RAM and, hence, interacts with the computer or processor as described under

    RAM except that it does not lose its contents when power is removed.

    Fig 4: wireless barcoder reader application in i-phone