RFID BASED MUSIUM GUIDE FOR TOURISTS

INDEX Contents Page No.

Abstract………………………………….....

Introduction to Embedded systems……

Microcontroller AT89S52.......................

Hardware Description………………….

Serial Communication Basics..........

Coding…………………………………......

Software Description……………………

Conclusion……………………………….

References……………………………….

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RFID Based Museum Guide for Tourists

ABSTRACT

RFID enabled tour assistant is expected to replace tourist guides to an extent. Its a

voice enabled device that speaks out as the tourist is traveling from places to places

(museum). When the tourist is standing near major landmarks, it will detect the RFID

tag and will play an audio clip relevant to that location.

This is achieved by placing a RFID receiver with the tourist (palm device). as soon

as the palm device comes in the vicinity id the RF tag the microcontroller receives the

RF tag unique id from the receiver and matches it with it's own data base. If match

occurs the microcontroller will play an audio clip relevant to that statue/painting. Audio

files are tagged with location coordinates and a tolerance range. In a particular location,

the file that matches the tolerance range are played. The buzzer is used to give audio

indication and the information related to a particular object is displayed on LCD.

An RFID module basically consists of two parts, namely, a tag and a reader. A

typical RFID system consists of an antenna, a transceiver and a transponder (RF tag).

The radio frequency is read by the transceiver and the information is transferred to a

device for further processing. The information (the unique serial number) to be

transmitted is stored in the RF tag or transponder.

The transponder contains a chip and an antenna mounted on a substrate. The chip

transmits the relevant information through antenna. The antenna also receives the

electromagnetic waves sent by the RFID reader.

Different RFID tags work on different frequencies. Here low frequency, 125 kHz,

RFID tags have been used. These tags work within a range of 10 cm. When an RFID

tag comes in this range, the reader detects it and sends a unique code of the tag

serially. This serial code, consisting of 12 bytes, is received by the microcontroller.

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Block Diagram:

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1.1 EMBEDDED SYSEMS

Embedded systems have grown tremendously in recent years, not only in their popularity

but also in their complexity. Gadgets are increasingly becoming intelligent and autonomous.

Refrigerators, air-conditioners, automobiles, mobile phones etc are some of the common

examples of devices with built in intelligence. These devices function based on operating and

environmental parameters.

The intelligence of smart devices resides in embedded systems. An embedded system, in

general, in co-operates hardware, operating systems, low-level software binding the operating

system and peripheral devices, and communication software to enable the device to perform the

pre-defined functions. An embedded system performs a single, well-defined task, is tightly

constrained, is reactive and computes results in real time.

Let us take a detailed look at these features of embedded systems:

Single functioned: An embedded system executes a specific program repeatedly.

For example, a pager is always a pager. In contrast a desktop system executes a variety of

programs like spreadsheets, word processors, etc. However there are exceptions where in an

embedded system’s program is updated with newer program versions. Cell phones are examples

of being updated in such a manner.

Tightly constrained: All computing systems have constraints on design metrics but

those on embedded systems can be especially tight. A design metric is a measure of an

implementation’s features, such as cost, size performance and power.

Reactive and real time: Many embedded systems must continually react to changes

in the system’s environment and must compute certain results in real time without delay.

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Embedded Hardware

All embedded systems need a microprocessor, and the kinds of microprocessors used in

them are quite varied. A list of some of the common microprocessor families is the ZILOG Z8

family, Intel 805/80188/x 86 families, Motorola 68k family and the PowerPC family.

Embedded Software

The software for the embedded systems is called firmware. The firmware will be written

in assembly languages for time or resource critical operations or using higher-level languages

like C or embedded C. The software will be simulated using micro code simulators for the target

processor. Since they are supposed to perform only specific tasks these programs are stored in

Read Only Memories (ROM’s).

Application areas for embedded systems

Embedded software is present in almost every electronic device you use today. There is

embedded software inside your watch, cellular phone, automobile, thermostats, Industrial control

equipment and scientific and medical equipment. Defence services use embedded software to

guide missiles and detect aircraft’s. Communication satellites, medical instruments and deep

space probes would have been nearly impossible without these systems. Embedded systems

cover such as broad range of products that generalization is difficult.

Here are some broad categories.

Aerospace and Defense Electronics (ADE)

Consumer/Internet applications

Data Communications

Digital imaging

Medical electronic Mobile data infrastructures

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Embedded System

Software Hardware

ALPCVB Etc.,

ProcessorPeripheralsmemory

Block diagram of Embedded System:

Figure 1.1: Embedded System Block Diagram

Software deals with the languages like ALP, C, and VB etc., and Hardware deals with

Processors, Peripherals, and Memory.

Memory: It is used to store data or address.

Peripherals: These are the external devices connected

Processor: It is an IC which is used to perform some task

Processors are classified into four types like:

1. Micro Processor (µp)

2. Micro controller (µc)

3. Digital Signal Processor (DSP)

4. Application Specific Integrated Circuits (ASIC)

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1.2 Objective of the Project:

In this application, we have proposed an RFID based museum guide for tourists which

can help tourists to provide necessary information related to the particular item in museum. It is

done with the help of voice chip IC which stores predefined voice messages. Those voice

messages are played according to the corresponding RFID tags.

BLOCK DIAGRAM

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AT 89S52 Microcontroller

RFID READER

RFID TAGS

LCD Display

Voice Chip Module

Speaker

3.MICROCONTROLLER

Basically, a microcontroller is a device which integrates a number of the components of a

microprocessor system onto a single microchip. So a microcontroller combines onto the same

microchip. The following components:

CPU Core

Memory (Both RAM and ROM)

Some Parallel Digital I/Os

The microprocessor is the integration of a number of useful functions into a single IC

package. Has the ability to execute a stored set of instructions to carry out user defined tasks;

also has ability to access external memory chips to both read and write data from and to the

memory.

Essentially, a microcontroller is obtained by integrating the key components of

microprocessor, RAM, ROM, and Digital I/O onto the same chip die. Modern microcontrollers

also contain a wealth of other modules such as Serial I/O, Timers, and Analogue to Digital

Converters. There are a large number of specialized devices with additional modules for specific

needs. E.g. CAN controllers.

MICROCONTOLLER (AT89S52)8

FEATURES

• Compatible with MCS-51 Products

• 8K Bytes of In-System Programmable (ISP) Flash Memory

• 4.0V to 5.5V Operating Range

• Fully Static Operation: 0 Hz to 33 MHz

• 256Bytes Internal RAM

• 32 Programmable I/O Lines

• 3 16-bit Timer/Counters

• Full Duplex UART Serial Channel

DESCRIPTION OF MICROCONTROLLER AT 89S52:

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The AT89S52 is a low-power, high-performance CMOS 8-bit micro

controller with 8Kbytes of in-system programmable Flash memory. The device is

manufactured

Using Atmel’s high-density non-volatile memory technology and is compatible

with the industry-standard 80C51 micro controller. The on-chip Flash allows the program

memory to be reprogrammed in-system or by a conventional non-volatile memory programmer.

By combining a versatile 8-bit CPU with in-system programmable flash one monolithic chip; the

Atmel AT89S52 is a powerful micro controller, which provides a highly flexible and cost-

effective solution to many embedded control applications.

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The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of

RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, full

duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is

designed with static logic for perationdown to zero frequency and supports two software

selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM

timer/counters, serial port, and interrupt system to continue functioning. The Power-down

mode saves the RAM contents but freezes the oscillator, disabling all other chip functions

until the next interrupt or hardware reset.

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PIN DESCRIPTION OF MICROCONTROLLER AT89S52

VCC

Supply voltage.

GND

Ground.

Port 0

Port 0 is an 8-bit open drain bi-directional I/O port. As an output port, each pin can sink

eight TTL inputs. When 1sare written to port 0 pins, the pins can be used as high impedance

inputs. Port 0 can also be configured to be the multiplexed low order address/data bus during

accesses to external program and data memory. In this mode, P0 has internal pull-ups. Port 0

also receives the code bytes during Flash programming and outputs the code bytes during

program verification. External pull-ups are required during program verification.

Port 1

Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 1 Output

buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled

high by the internal pull-ups and can be used as inputs. In addition, P1.0 and P1.1 can be

configured to be the timer/counter 2 external count input

(P1.0/T2) and the timer/counter 2 trigger input P1.1/T2EX), respectively, as shown in

the following table. Port 1 also receives the low-order address bytes during Flash programming .

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Port 2

Port 2 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 2 output

buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled

high by the internal pull-ups and can be used as inputs. Port 2 emits the high-order address

byte during fetches from external program memory and during accesses to external data

memory that uses 16-bit addresses (MOVX @DPTR). In this application, Port 2 uses strong

internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit

addresses (MOVX @ RI), Port 2emits the contents of the P2 Special Function Register. Port

2 also receives the high-order address bits and some control signals during Flash

programming and verification.

Port 3

Port 3 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 3 output buffers

can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the

internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled

low will source current (IIL) because of the pull-ups. Port 3 also serves the functions of various

special features of the AT89S52, as shown in the following table.

Port 3 also receives some control signals for Flash programming and verification.

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RST

Reset input. A high on this pin for two machine cycles while the oscillator is running

resets the device.

ALE/PROG

Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during

accesses to external memory. This pin is also the program pulse input (PROG) during Flash

programming. In normal operation, ALE is emitted at a constant rate of1/6 the oscillator

frequency and may be used for external timing or clocking purposes. Note, however, that one

ALE pulse is skipped during each access to external data Memory. If desired, ALE operation can

be disabled by setting bit 0 of SFR location

8EH. with the bit set, ALE is active only during a MOVX or MOVC

instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no

effect if the micro controller is in external execution mode.

PSEN

Program Store Enable (PSEN) is the read strobe to external program memory. When the

AT89S52 is executing code from external program memory, PSEN is activated twice each

machine cycle, except that two PSEN activations are skipped during each access to external

data memory.

EA/VPP

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External Access Enable. EA must be strapped to GND in order to enable the device to fetch

code from external program memory locations starting at 0000H up to FFFFH. Note,

however, that if lock bit 1 is programmed, EA will be internally latched on reset. A should

be strapped to VCC for internal program executions. This pin also receives the 12-

voltProgramming enables voltage (VPP) during Flash programming.

XTAL1

Input to the inverting oscillator amplifier and input to the internal clock operating circuit.

XTAL2

Output from the inverting oscillator amplifier.

Oscillator Characteristics

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier

that can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a

quartz crystal or ceramic resonator may be used. To drive the device from an

External clock source, XTAL2 should be left unconnected while XTAL1 is driven,

as shown in Figure 2.

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4. Radio Frequency Identification (RFID) Basics

Radio Frequency Identification (RFID) is a system that facilitates the tracking of objects,

primarily for inventory tracking, via a three-part technology comprised of a reader, a transceiver

with decoder and a transponder (RF Tag). RFID is a wireless system that works in conjunction

with an organization’s information technology infrastructure to improve business processes such

as inventory management and efficiency in supply chain management.

The RFID is not a new technology. For example, the principles of RFID were employed

by the British in World War II to identify their aircraft using the IFF system (Identify Friend or

Foe). Later, work on access control that is more closely related to modern RFID, was carried at

Los Alamos National Laboratories during the 1960s, RFID tags incorporated in employee badges

enabled automatic identification of people to limit access to secure areas, and had the additional

advantage that it made the badges hard to forge. For many years this technology has been

adopted in various domains, such as to identify animals, make toys interactive, improve car-key

designs, label airline luggage, time marathon runners, prevent theft, enable automatic toll-way

billing (smart tag), and many forms of ID badge for access control. Today, it is even being

applied to validate money and passports, and as a tamper safeguard for product packing.

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Fig 4.1: RFID chip

4.1 RFID Frequencies

Radio-frequency (RF) signals are typically sinusoidal or nearly so that is, the voltage or

field is a smooth, periodic function of time.  The number of times the signal repeats itself per

second, the frequency, varies widely in differing RFID systems.  Frequency is measured in

Hertz (Hz): one Hertz is one cycle per second.   KHz= 1000's of Hz; MHz = millions of Hz.  

The figure below shows some of the common and less-common frequency bands in

which RFID systems operate.  Also shown is the corresponding wavelength - the distance

between points at which the field has a fixed value when the signal moves at the velocity of

light.

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Table 4.1: RFID operating frequencies and characteristics.

4.2 RFID Topology:

An RFID system consists of a tag made up of a microchip with an antenna, and an

interrogator or reader with an antenna. The reader sends out electromagnetic waves. The tag

antenna is tuned to receive these waves. A passive RFID tag draws power from the field created

by the reader and uses it to power the microchip's circuits. The chip then modulates the waves

that the tag sends back to the reader, which converts the new waves into digital data. In its

minimalist configuration the micro-topology requires just four sub-systems, as follows:

i. Tag

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ii. Reader

iii. Air Interface

iv. Computer Communication and Control

The most demanding macro-topology involves pervasive tagging where sophisticated

Readers are simultaneously interrogating multiple tags in a dynamic environment. In this

scenario, anti collision algorithms are required in addition to data handling processes for large

velocity data streams.

Fig 4.2 Basic RFID Interface

Basic RFID system consists of three components

a. Tags

The basic RFID building blocks are miniature electronic devices known as Tags which talk

to Readers. The RFID tags, also known as transponder, are usually small pieces of material,

typically comprising three components: an antenna, a microchip unit containing memory storage

an encapsulating material. Tag are embedded or attached to an item. The Tag has memory which

stores information as either read only, write once or unlimited read/write. Tags typically range in

size from a postage stamp to a book, depending on read distance and features. RFID tags come in

a wide variety of shapes and sizes.

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Fig 4.3: RFID Tags

RFID tags are categorized into active and passive. They are fundamentally distinct

technologies with substantially different capabilities. Both of the technology use radio frequency

energy to communicate between a tag and a reader, the method of powering the tags is different.

Active RFID tags are powered by an internal battery or internal power source continuously

power the tag and its RF communication circuitry and are typically read/write, i.e., tag data can

be rewritten and/or modified.

While passive RFID tags operate without a separate external power source and obtain

operating power generated from the reader. The passive RFID relies on RF energy transferred

from the reader to be tag to power the tag. Passive tags are consequently much lighter than active

tags, less expensive, and offer a virtually unlimited operational life time.

b. Reader:

The Reader is able to talk to the Tag using radio waves over the air to send or receive

information. The distance between the Tag and Reader for the radio waves to be strong enough

for the devices to talk with each other is an important specification in building a reliable RFID

system. Once you have reliable radio communications between the Tag and the Reader the

system may take action based on results of their communication. RFID may send information

downstream to your legacy systems or update digital information stored on the Tag. This wide

range of options and the real time capability of RFID give it exciting new capabilities, distinct

advantages and specific costs to build its infrastructure.

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RFID systems are also distinguished by their frequency ranges. Low-frequency (30 KHz to

500 KHz) systems have short reading ranges and lower system costs. They are most commonly

used in security access, asset tracking, and animal identification applications. High-frequency

(850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) systems, offering long read ranges (greater than

90 feet) and high reading speeds, are used for such applications as railroad car tracking and

automated toll collection. However, the higher performance of high-frequency RFID systems

incurs higher system costs.

Different countries have allotted different parts of the radio spectrum for RFID, so no single

technology optimally satisfies all the requirements of existing and potential markets. The

industry has worked diligently to standardize three main RF bands: low frequency (LF), 125 to

134 kHz; high frequency (HF), 13.56 MHz; and ultrahigh frequency (UHF), 860 to 960 MHz.

Most countries have assigned the 125 or 134 kHz areas of the spectrum for low-frequency

systems, and 13.56 MHz is used around the world for high-frequency systems (with a few

exceptions), but UHF systems have only been around since the mid-1990s, and countries have

not agreed on a single area of the UHF spectrum for RFID.

c. An RFID antenna:

Connected to the RFID reader, can be of various size and structure, depending on the

communication distance required for a given system’s performance. The antenna

activates the RFID tag and transfers the data by emitting pulses.

4.3 Potential Uses of RFID Technology:

Many public and private sector organizations are either using or planning to use RFID

technology.  Because the technology basically turns an inert object into one capable of

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communicating, the potential for use is enormous and limited only by our imagination and the

capabilities of the technology involved.  Potential uses include:

a. Supply Chain Management (monitoring and controlling the flow of goods from raw

materials through to finished product, from manufacturer to consumer);

b. Product Integrity (ensuring that products (e.g., pharmaceuticals) are authentic and have

not been altered in any way);

c. Warranty Services (marking durable goods with a tag incorporating a product registration

code to facilitate warranty services);

d. ID, Travel, and Ticketing (providing a means to verify the identity of the traveler and to

ensure that the documents are genuine);

e. Baggage Tracking (monitoring and controlling the movement of baggage from check-in

to loading on an airplane); and

f. Patient Care and Management (providing a means to rapidly and accurately verify

information concerning patient allergies, prescription history, etc. to prevent surgical

errors).

Advantages of RFID

a. No line of sight requirement.

b. The tag can stand a harsh environment.

c. Long read range. Larger area of coverage. Up to several feet.

d. Portable database

e. Multiple tag read/write.

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f. Tracking people, items, and equipment in realtime. Non-line of sight

identification of tags

g. Unattended operations are possible, minimizing human errors and high cost.

h. Ability to identify moving elements that have tags embedded.

i. Can be used in diverse environments, including live stock, military, and scientific

areas.

j. RFID can be used in addition to Bar Code. These two technologies can be

complementing each other.

k. Automatic integration with back end software solutions provide end to end

integration of data in real time.

l. Labor reduction

m. Enchanced visibility and forecasting

n. Improved inventory management.

o. Simultaneous automatic reading.

5. Hardware Description

5.1 Power supply description:

As the microcontroller operating voltage is +5V DC. Through this power supply circuit

we have to create a +5V DC which is given to the micro controller. The below components are

used to create the power supply

Fig

5.1 Block Diagram of Power Supply

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RegulatorFilterBridge rectifier

Step down transformer

230V AC supply

Description:

230V AC supply is given to the step down transformer of 12A type. It may be a 230V to

9V or 12V step down transformer. The output of the step down transformer is given to bridge

rectifier. The bridge rectifier is formed with 1N4007 diodes. The bridge rectifier converts the AC

Voltage into DC Voltage. But the output DC Voltage contains some AC component (ripples). So

we use a capacitors-2200uF/25V, 0.1uF/D and resistor of 10K as a filter for removing ripples.

That output DC Voltage is given to the positive voltage regulator LM7805 (i.e., 78 represents the

positive series and 5 represent the output voltage it can provide). So the output of the regulator

will be the regulated +5V DC. To indicate the condition of the circuit we place a LED at the end

of the circuit.

Fig 5.2 Schematic of Power Supply

Voltage Regulators

Voltage regulators comprise a class of widely used ICs. Regulator IC units contain the

circuitry for reference source, comparator amplifier, control device, and overload protection all

in a single IC. IC units provide regulation of either a fixed positive voltage, a fixed negative

voltage, or an adjustably set voltage. A fixed three-terminal voltage regulator has an unregulated

dc input voltage, Vi, applied to one input terminal, a regulated dc output voltage, Vo, from a

second terminal, with the third terminal connected to ground.

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The series 78 regulators provide fixed positive regulated voltages from 5 to 24 volts.

Similarly, the series 79 regulators provide fixed negative regulated voltages from 5 to 24 volts.

IC Voltage Regulators

Voltage regulator ICs are available with fixed (typically 5, 12 and 15V) or variable

output voltages. They are also rated by the maximum current they can pass. Negative voltage

regulators are available, mainly for use in dual supplies. Most regulators include some automatic

protection from excessive current ('overload protection') and overheating ('thermal protection').

Many of the fixed voltage regulator ICs has 3 leads and look like power transistors,

5.3: Voltage Regulator Circuit

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Fig 5.4: IC Voltage Regulator

5.5 LIQUID CRYSTAL DISPLAY

A liquid crystal display (LCD) is a thin, flat display device made up of any number of

color or monochrome pixels arrayed in front of a light source or reflector. Each pixel consists of a

column of liquid crystal molecules suspended between two transparent electrodes, and two

polarizing filters, the axes of polarity of which are perpendicular to each other. Without the

liquid crystals between them, light passing through one would be blocked by the other. The

liquid crystal twists the polarization of light entering one filter to allow it to pass through the

other.

For an 8-bit data bus, the display requires a +5V supply plus 11 I/O lines. For a 4-bit data

bus it only requires the supply lines plus seven extra lines. When the LCD display is not enabled,

data lines are tri-state and they do not interfere with the operation of the microcontroller.

Data can be placed at any location on the LCD. For 16×2 LCD, the address locations

are:

First line 80 81 82 83 84 85 86 through 8F

Second line C0 C1 C2 C3 C4 C5 C6 through CF

A ddr ess lo cations for a 2 x16 li ne LCD

SIGNALS TO THE LCD

The LCD also requires 3 control lines from the microcontroller:

1) E n a b le (E)

This line allows access to the display through R/W and RS lines. When this line is

low, the LCD is disabled and ignores signals from R/W and RS. When (E) line is high, the

LCD checks the state of the two control lines and responds accordingly.

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2) Read/Write (R / W )

This line determines the direction of data between the LCD and microcontroller.

When it is low, data is written to the LCD. When it is high, data is read from LCD.

3) R e gi ster s e l e ct ( R S)

With the help of this line, the LCD interprets the type of data on data lines. When it is low,

an instruction is being written to the LCD. When it is high, a character is being written to LCD.

Logic s t atus on c o n t r o l lines:

• E - 0 Access to LCD disabled

- 1 Access to LCD enabled

• R/W - 0 Writing data to LCD

- 1 Reading data from LCD

• RS - 0 Instruction

- 1 Character

W r i t i n g a n d r e ad ing the d a t a f r om the L C D:

Writing data to the LCD is done in several steps:

1) Set R/W bit to low

2) Set RS bit to logic 0 or 1 (instruction or character)

3) Set data to data lines (if it is writing)

4) Set E line to high

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5) Set E line to low

Read data from data lines (if it is reading):

1) Set R/W bit to high

2) Set RS bit to logic 0 or 1 (instruction or character)

3) Set data to data lines (if it is writing)

4) Set E line to high

5) Set E line to low

P I N D E S C RI P T I ON

Most LCDs with 1 controller has 14 Pins and LCDs with 2 controller has 16 Pins

(two pins are extra in both for back-light LED connections).

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Fig 5.10: Basic LCD Interfacing Circuit

Pin Configuration:

Fig 5.11 Pin Configuration of 16X2 Lcd

5.6UART:

Fig 5.12 UART Block Diagram

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ComputerUART driver Microcontroller

Atmel microcontroller features a full duplex (separate receive and transmit registers) Universal

Asynchronous Receiver and Transmitter (UART).

The main features are:

• Baud rate generator that can generate a large number of baud rates (bps)

• High baud rates at low XTAL frequencies

• 8 or 9 bits data

• Noise filtering

• Overrun detection

• Framing Error detection

• False Start Bit detection

• Three separate interrupts on TX Complete, TX Data Register Empty and RX Complete.

The alternative function of portd0, portd1 is UART. Portd0 is the receiver pin and portd1 is the

transmitter pin. Here we are using IC MAX232 as a UART driver.

This micro controller board contains max232 IC which is used as a voltage converter.

Fig 5.13 Max 232 Schematics

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The output supply of computer will be 10V and we require 5V of supply for our microcontroller

board.

When we want to take some input from the computer to the micro controller, then we require

some means in order to down convert that 10V to 5V. This is done through max232 IC.

Similarly, when we are reading some thing from the micro controller in to the micro controller,

then we need some up converter that converts 5V to 10V to the computer. This is also done

through max232 only.

This all work is done through the 4 capacitors present near the max232. These capacitors provide charge when required and store the charge when not required.

So, Max232 requires:-

power supply of 5V

2 RS232 Drivers

4 External Capacitors of 1micro farad

Dual charge pumps DC-DC voltage converters

Receiver and Transmitter Enable control pins.

Temperature of 00to +700 .

The transmit pin of the micro controller [txd] pin 11 is connected to pin no 10 of MAX 232 IC.

The receive pin of the micro controller [rxd] pin 10 is connected to pin no 9 of MAX 232 IC. In

the DB9 connector pin no 5 is GROUND. Pin no 2 is receive pin. Pin no 3 is Transmit pin.

5.7 RESET CIRCUIT:

Reset pin is used in the controller board in order to bring back the controller to the initial

position. The reset circuit will be in the following manner:

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Fig 5.14 Reset Circuit Schematic

Reset circuit contains one zener diode which operates in reverse bias, one tic-tac switch, one

tantalum capacitor and one resistor.

Vcc is the supply of +5V which we are giving to the controller board. This supply passes

through the zener diode to the controller through pin no. 9. The reset pin here works in active

low position. Active low means that whenever we are providing the supply, it will go to the

controller. When we are grounding the circuit once, it shows the reset operation. Now, in this

circuit, when we press the reset button (tic-tac switch), then the supply will be grounded which

means that the supply has been stopped and when we release the switch the controller comes to

the initial position. Tantalum capacitor is used here in order to protect the controller from the

spike voltages caused due to the sudden change in the voltage when we press and release the tic-

tac switch.

5.9 VOICE MODULE:

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APR9600 device to reproduce voice signals in their natural form. It eliminates the

need for encoding and compression, which often introduce distortion. The APR9600 device

offers true single-chip voice recording, non-volatile storage, and playback capability for 40 to 60

seconds. The device supports both random and sequential access of multiple messages. Sample

rates are user-selectable, allowing designers to customize their design for unique quality and

storage time needs. Integrated output amplifier, microphone amplifier, and AGC circuits greatly

simplify system design. The device is ideal for use in portable voice recorders, toys, and many

other consumer and industrial applications. APLUS integrated achieves these high levels of

storage capability by using its proprietary analog/multilevel storage technology implemented in

an advanced Flash non-volatile memory process, where each memory cell can store 256 voltage

levels. This technology enables the APR9600 device to reproduce voice signals in their natural

form. It eliminates the need for encoding and compression, which often introduce distortion.

Fig 5.15 Pin Diagram of APR 9600

Circuit Diagram of APR9600 Module

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Fig 5.15: Schematic for APR 9600 Voice Chip

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6.2 Project Coding:

//Program to interface RFID with 8051 microcontroller (AT89C51) #include<reg51.h>unsigned int data_out,command=0x80,temp;sfr lcd_data_pin=0xA0; //P2 portsbit rs=P1^0;        //Register select sbit rw=P1^1;        //Read/Write sbit en=P1^2;        //Enable pinunsigned char card_id[12];

void delay(unsigned int count)    //Function to provide delay{    int i,j;     for(i=0;i<count;i++)     for(j=0;j<1275;j++);}

void lcd_command(unsigned char comm)   //Lcd command funtion{     lcd_data_pin=comm;     en=1;     rs=0;     rw=0;     delay(1);     en=0;}

void lcd_data(unsigned char disp)  //Lcd data function{     lcd_data_pin=disp;     en=1;     rs=1;     rw=0;     delay(1);     en=0;}

lcd_string(unsigned char *disp)     //Function to send string {     int x;     for(x=0;disp[x]!=0;x++)    {         lcd_data(disp[x]);    }}

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void lcd_ini()                  //Function to initialize the LCD{    lcd_command(0x38);              delay(5);    lcd_command(0x0F);            delay(5);    lcd_command(0x80);    delay(5);} 

void recieve()     //Function to recieve data serialy from RS232 {    unsigned char k;     for(k=0;k<12;k++)     {          while(RI==0);           card_id[k]=SBUF;          RI=0;    }}

void main(){    int l;    TMOD=0x20;            //Enable Timer 1    TH1=0XFD;    SCON=0x50;    TR1=1;                // Triggering Timer 1    lcd_ini();    lcd_command(0x81);        //Place cursor to second position of first line     lcd_string("UNIQUE CARD ID:");    delay(200);    while(1)    {         recieve();         lcd_command(0xC1);        //Place cursor to second position of second line         for(l=0;l<12;l++)         {               lcd_data(card_id[l]);          }      }}

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7. Software Description Embedded ’c’

Keil software

Installing the Keil software on a Windows PC

Insert the CD-ROM in your computer’s CD drive

On most computers, the CD will “auto run”, and you will see the Keil installation menu.

If the menu does not appear, manually double click on the Setup icon, in the root

directory: you will then see the Keil menu.

On the Keil menu, please select “Install Evaluation Software”. (You will not require a

license number to install this software).

Follow the installation instructions as they appear.

Loading the Projects

The example projects for this book are NOT loaded automatically when you install the Keil

compiler.

These files are stored on the CD in a directory “/Pont”. The files are arranged by chapter: for

example, the project discussed in Chapter 3 is in the directory “/Pont/Ch03_00-Hello”.

Rather than using the projects on the CD (where changes cannot be saved), please copy the files

from CD onto an appropriate directory on your hard disk.

Note: you will need to change the file properties after copying: file transferred from the CD will

be ‘read only’.

Configuring the Simulator

Open the Keil Vision2

go to Project – Open Project and browse for Hello in Ch03_00 in Pont and open it.

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Go to Project – Select Device for Target ‘Target1’

Select 8052(all variants) and click OK

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Now we need to check the oscillator frequency:

Go to project – Options for Target ‘Target1’

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Make sure that the oscillator frequency is 12MHz.

Building the Target

Build the target as illustrated in the figure below

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Running the Simulation

Having successfully built the target, we are now ready to start the debug session and run the

simulator.

First start a debug session

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The flashing LED we will view will be connected to Port 1. We therefore want to observe the

activity on this port

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To ensure that the port activity is visible, we need to start the ‘periodic window update’ flag

Go to Debug - Go

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While the simulation is running, view the performance analyzer to check the delay durations.

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Go to Debug – Performance Analyzer and click on it

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Double click on DELAY_LOOP_Wait in Function Symbols: and click Define button

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8. Conclusion

The project “RFID Based Museum Guide For Tourists” has been successfully completed and tested

with Integration of the features of every hardware component for its development. Presence of every block

has been reasoned out and placed carefully thus contributing to the best working of the unit.

The project was finished using very simple and easily available components making it lightweight and

portable. This helps tourists to move in any premises of museum with the help of RFID Technology. The

voice chip module is also interfaced for audio playback for the recorded voice messages relevent to particular

object. I believe that our step is towards complete automated guidance system for tourists.

Finally I can conclude that this project application gives a very good features and there is huge scope

for further research and development for using the same with the help of advanced technology.

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9.Bibliography:

1) P. Bahl and V. N. Padmanabhan, “RADAR: An In-Building RF-based User Location and

Tracking System,” in Proc. IEEE INFOCOM, 2000, pp. 775–784.

2) P. Krishnan, A. S. Krishnakumar , Wen-Hua Ju , Colin Mallows , Sachin Ganu A System

for LEASE: Location Estimation Assisted by Stationary Emitters for Indoor RF Wireless

Networks, IEEE INFOCOM 2004, March 7-11, 2004, Hong Kong.

3) Leonard E. Miller, “Indoor Navigation for First Responders: A Feasibility Study,”

Technical Report, National Institute of Standards and Technology, February 2006.

4) Hirohiko Ohkubo, Seiji Kitakaze, Yo Fujishima, Naoto Watanabe, Minoru Kamata,

“Integrated Way Finding/Guidance system using GPS/IR/RFID with mobile device,

Technology & Persons with Disabilities Conference, March 14-19, 2005, Los Angeles.

5) S. Willis, S. Helal, “RFID information grid for blind navigation and wayfinding,” in

Proceedings of the Ninth IEEE International Symposium on Wearable Computers, 2005

18-21 Oct. 2005.

6) Jongwhoa Na, The Blind Interactive Guide System Using RFID-Based Indoor

Positioning System, in Computers Helping People with Special Needs, LNCS Volume

4061, ISBN 978-3-540-36020-9, 2006.

7) www.atmel.com for ATMega8515 micro controller

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