1

ABSTRACT

As the world advances to the modern information age lot of automation

solutions has-been introduced in various fields in order to maintain on

time, secured and low cost services to meet the needs of the fast moving

society In light of the importance of science and technology in the world

today, there is a need for scholarly works on its social dimension. Now a

day’s every system is intelligent and effective to face the challenges in

the easy way by considering the flexibility, reliability and high accuracy.

More electronics development is obtained in the field of

commercialization rather than the social sophistication. So here is the

project called Blind Sticks which deals with the supporting of the difficult

phenomenon of the blind people of our society. For the blinds as well as

visually impaired peoples the endeavors and researchers have spend the

decades to develop an intelligent and smart stick to protect and alert them

form obstacles these paper provides a new method for the guidance of

such peoples. This is an intelligent stick which is very different and

standardized then other simpler sticks. This is equipped with the IR

transmitter and receiver that give the information about the environment.

This information is processed and delivered to the users in audio form

and thus can be interpreted by the user.

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Chapter 1

INTRODUCTION

The importance of sensorial and communicational functions results from

the facts that the human body is an open bio system. The human being

receives information from the environment 1%by test ,1.5%by tactile

sense, 3.5%by smell, 11% by hear and 83% sight. For and efficient

reintegration of the disabled people in the family and society, it is

strongly needful to assist their totally lost functions and diminished

functions. This system helps to the peoples by solving many problems

and provides mobility assistance, safe and convenient way and decreases

the probable injuries can happen from accident.

1.1 BACKGROUND

Mobility for the blind people can be defined as the ability to move with

ease, speed and safety through his environment independently. It is

essential because that there are 180 millions peoples in the world

currently who are affected by the visual problems. With this number

approximately 40-50 million peoples are blind or cannot walk

independently. The blind people think the blindness is their weakness and

a cause to be humiliation. In many cases blind peoples are hated by the

society and their own family also. To support and help such peoples in

their daily life activities such as movement from one place to another

place and provide a comfortable walk around the road by without

anybody help. Sight loss is very often accompanied by a loss of

independence. So this system provides mobility assistance. For blind

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people with the detection of obstacles with the help of IR sensors and

microcontroller, providing them a audio alarm and solve many problem

such as the person can leave home by themselves in a safe and convenient

way, participating in more social function and other activates to provide

more convenient means and improve their quality life.

1.2 PROBLEM STATEMENT

Blind people have difficulty to interact and feel their environment.

Physical movement is a challenge for visually impaired peoples because

it is difficult to go from one place to another place. Over half of the

legally blind people in the world are unemployed because limited type’s

jobs they can do. They are relaying on their families for mobility and

financial support. Their mobility opposes them from interacting with

people and social activates. In the past different systems are designed

with limitations without a solid understanding of the non visual

perception. Some of the systems are only for indoor and no hurdle

detections. The available systems are very costly; some of the systems are

heavy cause physical fatigue and required training to use.

1.3 OBJECTIVES

The project “intelligent blind stick” has been constructed to meet the

following objectives:

(a) To regain the ability to travel independently with ease and

speed.

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(b) To prevent them from the probable injuries and accidents.

1.4 VIABLE AND AVAILABLE SYSTEMS

Over the last decades, research has been conducted for new devices to

design a good and reliable system for blind peoples to detect obstacles

and warn them at danger places.

1.4.1 VIABILITY

The intelligent blind sticks ensures and alternative channel for the

sensorial perception to provide a mobility assistance for the blind people

for safety and independency. Since the microcontroller is a general

purpose device which is used to provide audio output using fixed

programmed that is stored in ROM and doesn’t sense over the lifetime of

the system. Since it is cheap, versatile and flexible device, the use of such

system defines the abreast of technology and the exploration of skill in

related innovative fields of science and technology.

1.4.2 AVAILABLE SYSTEM

We mate several similar and dissimilar systems as our project. Different

students has convinced the basic idea about the project and implemented

in their own way unlike ours in a versatile and efficient manner. The

system can become a craze upon its proper utilization and mobilization

by implementing it into our project by using a programmable device

referred as microcontroller. Hence it is most effective system which

requires less manpower and work in reliable and efficient manner.

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1.5 METHODOLOGY

In order to obtain the efficient system following methods are carried out:

Case study.

Group discussion.

Concern with faculty’s teacher and supervisor.

Hardware part collection.

Coding.

Testing and modify.

Finalizing of the project.

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Chapter 2

ANALYSIS

2.1 PROJECT MANAGEMENT

We divided the task into various levels. The levels are:

1. Search for necessary information: We researched about our project

in the internet. We made a thought study about the components

required for the completion about the project. We also researched

about the upcoming obstacles which may be faced during our

projects.

2. Find out the necessary components in the market: All the necessary

components of our project were listed. All the required parts were

found and purchased from nearby electronics shop.

3. Bread board Testing: The components were tested in the bread

board similarly the program and the components testing were done.

4. PCB Designing and fabrication: PCB designing and fabrication

was done finally and the project was accomplished.

We also divided the task according to the best capabilities of the team

member and performed our respective task as well as a group task. And

the circuit was designed and components were bought from the market.

Some of the components we have used in our project are mentioned

below:-

Microcontroller AT89S52

Timer IC NE555

Regulator IC 7805

9V Battery

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IR Transmitter

IR receiver

Speaker

Relay

Resistor

Capacitor

Transistor

Diode

Crystal

Reset switch

Connecting wires

2.2 REQUIREMENT ANALYSIS

Requirement analysis is the critical to the success of a system. Our

project mainly focuses to solve the difficulties of people who are totally

blind and visually impaired. The idea behind this project arises after we

analyze the problem faced by such peoples in the travelling from one

place to another. Then we discussed how we can use the IR transmitting,

receiving technology or optoelectronics technology to overcome this

problem associated with blind and visually impaired people. We looked

towards our project from the view point of the user then we started

coding implementation and construction of this project. The information

about IR transmitter, photo transistor, IC555, and microcontroller

AT89S52 are taken from internet, book and others. From following, best

where chosen for the project. For this project the timer circuit using

IC555 provides a pulse for the IR transmitter, microcontroller and

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receiver. The IR transmitter transmits the IR and received by the IR

receiver after being reflected from the obstacles. Then the microcontroller

AT89S52 needs program based on requirement. The suitable

programming software was chosen verify the coding. If an error

interoperates, reprogram the microcontroller. Lastly the overall circuit

troubleshoots and tested.

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Chapter 3

SYSTEM MODELING

3.1 BLOCK DIAGRAM

Figure 3.1 Block Diagram of Intelligent Blind Stick

3.2 BLOCK DIAGRAM EXPLANATION

3.2.1 Microcontroller

The microcontroller is the heart of the circuit. The microcontroller used is

AT898S52. It controls all the function. It accepts the output of the IR

receiver and gives the audio output via speaker.

3.2.2 IC555 Timer

It is widely used timer circuit that has two modes of operation. They are

astable and monostable. In monostable mode it produces accurate time

delay and in astable mode it produces rectangular pulse.

Voltage

Regulator

Battery IR

Transmitter

Timer Relay

&Timer

IR Receiver

Microcontroller

Audio

output

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3.2.3 LM7805

This is an IC voltage regulator have output of constant positive voltage of

5 volts. Here it is use to provide fixed positive voltage for microcontroller

and for the IR receiver.

3.2.4 Relay

A relay is an electrically operated switch. Current following through the

coil of the relay creates a magnetic field which attracts a lever and

changes the switch contacts.

3.3 CIRCUIT DIAGRAM

Figure 3.3 Circuit diagram

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3.4 CIRCUIT DIAGRAM EXPLANATION

In this project we are going to provide the mobility assistance for the

blind and visually impaired peoples. The idea behind this particular work

is to give user the full flexibility and accuracy to detect the obstacle and

give audio alarm output.

The process to operate the circuit first of all the IC 555 timer is operated

in monostable mode to provide the rectangular pulse for the IR

transmitter. Two resistor and two capacitors are connected along with IC

555 to make it operate it into monostable mode. When the obstacle is

comes in front of the stick then the IR receiver detects the reflected IR.

The relay and timer circuit in the board gives the signal to the

microcontroller. The microcontroller is then reset. Microcontroller is then

programmed to give the output when the hurdle is comes front of the

blind person. Then the output of the microcontroller is then fed to the

speaker to give the audio output.

3.5 POWER SUPPLY

Figure 3.5 Power Supply Circuit

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The microcontroller and the other devices get the power supply from the

battery through the 7805, 5 volts regulator. A power supply of +5V is

required for the circuit operation. +5 supply is required by the

microcontroller, IC 555 timer, the relay circuit, IR transmitter and the

receiver circuit.

3.6 DETAILS OF THE COMPONENTS

3.6.1 MICROCONTROLLER AT89S52

The AT89S52 provides the following standard features: 8Kbytes of flash,

256 bytes of RAM, 32 I/O lines, three 16 bit timers/counters, six-vector

two-level interrupt architecture, a full duplex serial port, on-chip

oscillator, and clock circuitry. In addition, the AT89S52 is designed with

static logic for operation down 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

hardware reset. By combining a versatile 8-bit CPU with Flash on a

monolithic chip, the AT89S52 is a powerful microcomputer which

provides a highly flexible and cost effective solution to many embedded

control applications.

FEATURES OF MICROCONTROLLER

Compatible with MCS-51 Products.

8 Kbyte of In-System Reprogrammable Flash Memory.

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Endurance: 1,000 Write/Erase Cycle.

Fully Static Operation: 0 Hz to 24 MHz.

Three Level Program Memory Lock.

256 x 8-Bit Internal RAM.

32 Programmable I/O Lines.

Three 16 Bit Timer/Counters.

Eight vector two level Interrupt Sources.

In addition, the AT89S52 is designed with static logic for operation

down to zero frequency and supports two software selectable

power saving modes.

PIN CONFIGURATION

Figure 3.6 Pin Configuration of AT89S52

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PIN DESCRIPTION

VCC: Supply voltage for all packages

GND: Ground.

PORT 0: Port 0 is an 8-bit open drain bidirectional I/O port. As an output

port, each pin can sink eight TTL 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.

PORT1: Port 1 is an 8-bit bidirectional 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. As inputs, Port 1 pins that are externally being

pulled low will source current (IIL) because of the internal pull-ups. 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 and

verification.

Table 1: Alternate functions of Port1

Port Pin Alternate function

P1.0 T2 (external count input to Timer/Counter 2), clock-out

P2.0 T2EX (Timer/Counter 2 capture/reload trigger)

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PORT 2: Port 2 is an 8-bit bidirectional 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 inter-nal pull-ups and

can be used as inputs. As inputs, Port 2 pins that are externally being

pulled low will source current (IIL) because of the internal pull-ups. 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 uses 8-bit addresses (MOVX @ RI), Port 2 emits 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 bidirectional 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

receives some control signals for Flash programming and verification.

Port 3 also serves the functions of various special features of the

AT89S52, as shown in the following table.

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Table 2: Alternate Function of Port 3

Port Pin Alternate Functions

P3.0 RXD (serial input port)

P3.1 TXD (serial output port)

P3.2 INT0 (external interrupt 0)

P3.3 INT1 (external interrupt 1)

P3.4 T0 (timer 0 external input)

P3.5 T1 (timer 1 external input)

P3.6 WR (external data memory write strobe)

P3.7 RD (external data memory read strobe)

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 of 1/6 the oscillator

frequency and may be used for external timing or clocking purposes.

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.

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EA/VPP: 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. EA should be

strapped to VCC for internal program executions. This pin also receives

the 12-volt programming enable 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.

3.6.2 IC555 TIMER

The 555 timer IC is an integrated circuit (chip) used in a variety of timer,

pulse generation, and oscillator applications. The 555 can be used to

provide time delays, as an oscillator, and as a flip-flop element.

Derivatives provide up to four timing circuits in one package.

FEATURES

Supply voltage 4.5-9V.

Timing from microsecond to hours.

Monostable and Astable operation.

Adjustable duty cycle.

High temperature stability.

Output can be operated normal ON and OFF.

Relatively cheap, stable, and user-friendly integrated circuit.

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PIN CONFIGURATION

Figure 3.6.2.1 Pin Configuration of IC 555

PIN DISCRIPTION OF IC555 TIMER

Pin 1 (Ground): Connects to the 0v power supply.

Pin 2 (Trigger): Detects 1/3 of rail voltage to make output HIGH. Pin 2

has control over pin 6. If pin 2 is LOW, and pin 6 LOW, output goes and

stays HIGH. If pin 6 HIGH, and pin 2 goes LOW, output goes LOW

while pin 2 LOW. This pin has very high impedance (about 10M) and

will trigger with about 1uA.

Pin 3 (Output): Goes HIGH (about 2v less than rail) and LOW (about

0.5v less than 0v) and will deliver up to 200mA.

Pin4 (Reset): Internally connected HIGH via 100k must be taken below

0.8V to reset the chip.

Pin5 (Control): A voltage applied to this pin will vary the timing of the

RC network.

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Pin6 (Threshold): Detects 2/3 of rail voltage to make output LOW only

if pin 2 is HIGH. This pin has very high impedance and will trigger with

about 0.2uA.

Pin7 (Discharge): Goes LOW when pin 6 detects 2/3 rail voltage but pin

2 must be HIGH. If pin 2 is HIGH, pin 6 can be HIGH or LOW and pin 7

remains LOW.

Pin8 (Supply): Connects to the positive power supply. Commonly 5V

DC when working with digital ICs.

3.6.3 REGULATOR (LM 7805):

The LM 7805 monolithic 3-terminal positive voltage regulator employ

internal current limiting, thermal shutdown and safe area compensation,

making them essential indestructible. If adequate heat sinking is

provided, they can deliver over 1.0A output current. That is intended as

fixed voltage regulators in a wide range of application including local

(on-card) regulation for elimination of noise and distribution problems

associated with single –point regulation. In addition to use as fixed

voltage regulators, these devices can be use with external components to

obtain adjustable output voltages and currents. Considerable effort was

expended to make the entire series of regulators easy to use and minimize

the number of external components. It is not necessary to bypass the

output, although this does improve transient response. Input bypassing is

needed only if the regulator is located far from the filter capacitor of the

power supply.

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Figure 3.6.3 Regulator IC 7805

3.6.4 IR TRANSMITTER

When the switch is ON electrons are recombine with holes with in the

device, releasing energy in the form of photons. According the photons

different colors and the invisible IR is generated. Generally the IR

transmitter has range of 10-150cm. So it can detect the object near about

the 75 cm. IR has the spectral frequency of 300GHz to 400THz and

wavelength of 700nm-1mm. Generally IR has photon energy of

1.24meV – 1.7eV

3.6.5 IR RECEIVER

A typical system for detecting infrared radiation using infrared sensors

includes the infrared source such as blackbody radiators, tungsten lamps,

and silicon carbide. In case of active IR sensors, the sources are infrared

lasers and LEDs of specific IR wavelengths. Next is the transmission

medium used for infrared transmission. Optical components such as

optical lenses made from quartz, CaF2, Ge and Si, polyethylene Fresnel

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lenses, and Al or Au mirrors, are used to converge or focus infrared

radiation. The infrared detector completes the system for detecting

infrared radiation. The output from the detector is usually very small, and

hence pre-amplifiers coupled with circuitry are added to further process

the received signals.

Figure3.6.5IR Receiver

3.6.6 RESISTOR

Resistor is a component that resists the flow of direct or alternating

electric circuit. Resistor used in electric circuit is cylindrical. They are

often color coded by three or four color bands that indicate the specific

value of resistance. Resistors obey ohms law, which state that the current

density is directly proportional to the electric field when the temperature

is constant.

3.6.7 CAPACITOR

Capacitor or electric condenser is a device for storing an electric charge.

When one plate is charged with electricity from and direct current or

electrostatic source, the other plate have induce in it a charge of opposite

sign; that is, positive if the original charge is negative and negative if the

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original charge is positive. Capacitors are produced in a wide variety of

forms. Air, Mica, Ceramic, Paper, Oil and Vacuums are use as dielectrics

depending on the purpose for which the device is intended.

3.6.8 DIODE

Diode is an electronic device that allows the passage of current in only

one direction. The diodes commonly used in electronics circuits are

semiconductor diodes. There are different diodes used in electronic

circuit such as junction diode, Zener diode, photo diode and tunnel diode.

Junction diodes consist of junction of two different kind of semiconductor

material. The Zener diode is a special junction type diode, using silicon,

in which the voltage across the junction is independent of the current

through the junction.

3.6.9 CRYSTAL OSCILLATOR

The crystal oscillator is used to generate clock pulse for the

microcontroller. The crystal oscillator of 12MHz is used for

microcontroller AT89S52.

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3.6.10 RELAY CIRCUIT

Figure 3.6.10 Relay

A relay is an electrically operated switch. Current flowing through the

coil of the relay creates a magnetic field which attracts a lever and

changes the switch contacts. The coil current can be on or off so relays

have two switch positions and they are double through (change over)

switches. A single pole dabble throw (SPDT) relay is connected to port

RB1 of the microcontroller through a driver transistor. The relay requires

12 volts at a current of around 100ma, which cannot be provided by the

microcontroller. So the driver transistor is added. The relay is used to

operate the external solenoid forming part of a locking device or for

operating any other electrical devices. Normally the relay remains off. As

soon as pin of the microcontroller goes high, the relay operates and

releases.

3.6.11 SPEAKER

The speaker is for the audio output. When the obstacle is detected then

the microprocessor gives the signal to the speaker and the speaker

produces the audio output.

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Chapter 4

CODING

4.1 PROGRAMMING LANGUAGE

The programming language used is C programming language. This

language is one of the most widely used programming languages. This

language is also familiar with the students because C programming

language comes under our curriculum. Firstly we completed the coding in

this language and then we tested and convert into the HEX code by using

Keil software.

4.2ALGORITHM

1. Start.

2. Turn ON the switch of the circuit.

3. Press the Reset button of the microcontroller.

4. Generate the IR by IR transmitter.

5. If

Obstacle is detected go to step 6.

Else

Go to step no 8.

6. Generate the audio output and go to step 8.

7. Do not generate the audio output and go to step 8.

8. Stop.

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Chapter 5

LIMITATIONS AND MODIFICATION

5.1 LIMITATIONS

The project “Intelligent Blind Stick” has been constructed to meet many

objectives but it is not free from some limitations and they are:

1. The transmitter and receiver circuit has great power loss.

2. It cannot detect the obstacle far then 75cm.

5.2 FUTURE MODIFICATIONS

Our project entitled “Intelligent Blind Stick” can be developed into

various forms as per our design and requirements. Since we have used

Microcontroller, Timer IC55, IC LN7805, IR Transmitter and Receiver

circuit which really widen their scope and they are fruitful and essential.

Programmable embedded system as microcontroller is not only flexible

and customizable but cheap and stable enough. Future work will be

focused on enhancing the performance of the system and reducing the

load on the user by replacing the speaker’s tune by real human sound to

guide the blind exactly. Moreover, shape detection test for objects that

move at different rotational speeds across several distances will further be

considered. We can also add the GPS system to find the position of the

blind person.

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Chapter 6

CONCLUSION AND APPLICATIONS

6.1 CONCLUSION

The project we have undertaken has helped us to gain better perspective

on various aspects related to our course of study as well as practical

knowledge of electronic equipments. We become familiar with software

analysis, designing, implementation, testing and maintenance concerned

with our project. This stick is intelligent, simple, cheap, configurable,

easy to handle electronic guidance system is proposed to provide mobility

assistant and support for blind and visually impaired persons. The IR

sensor has been fully utilized in order to advance the mobility of the blind

and visual impaired people in safe and independent way. This system

does not require a huge device to be hold for a long distance, and it also

does not require any special training. This system also resolves

limitations that are related to the most of the movement problems that

may influence the blind people in their environment. This project given a

new opening for and expand the area of operation for the visually

impaired person by taking outside world as functional area. Before this

the blind person was bound to his building premises only. Our project

removes this restriction on him and help to live respected and quality life.

6.2 APPLICATIONS

This project is mainly applicable for the blind and visually

impaired people to provide them mobility assistance.

For the reduction of possible injuries can happen due to

blindness.

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SNAPSHOTS

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BIBLIOGRAPHY

1. Ramesh Gaonkar, Microprocessor Architecture, Programming and

Applications. Prentice Hall PTR, 2002 - Technology &

Engineering.

2. Albert Paul Malvino, Malvino Electronic Principles, 6th

edition,

Glencoe/McGraw-Hill School Publishing Company, 1999 -

Technology & Engineering.

3. Mazidi, The 8051 Microcontroller And Embedded Systems Using

Assembly And C, Pearson Education India, Sep 1, 2007 -

Embedded computer systems.

4. Programming In Microcontroller, Available: www.atmel.com

5. Datasheet for AT89S52/LM7805/IC555, Available:

www.catalogsheet.com

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APPENDICES

BLOCK DIAGRAM OF MICROCONTROLLER AT89S52

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BLOCK DIAGRAM OF IC555 TIMER

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TYPICAL CHARACTERISTICS OF IC 555

Fig 1. Minimum pulse width required for Fig 2. Supply current versus supply voltage

Triggering

Fig 3. Delay time versus temperature Fig 4. Delay time versus supply voltage