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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