SlideShare uma empresa Scribd logo
1 de 4
Assisting Blind person using DIjkstra’s shortest
                   path algorithm
       This Project comprises of a Hardware mechanical model which is
controlled by the electronic circuits to assist a blind person. I.e., This mechanical
model is attached with the walking stick of the blind person. The model will move
automatically. This model helps the blind person to reach the destination quickly.
The model has a wireless link to a nearby computer system through which it can
identify the shortest path. When the source and destination is selected the unit will
send the data to the computer. The computer will calculate the shortest path using
Dijkstra’s shortest path algorithm and transfers the route to the unit. The unit will
then tell the user to move in which direction. The movement of the user in ensured
using a RFID proximity cards and a reader. The reader will be placed on the unit
and on encountering of cards (Cards placed at each point) will tell the user has to
take right or left or straight through voice output. An APR 9600 voice storage and
retrival IC is used for this purpose. The unit will give alarm signal when it finds a
Obstacle. This project is divided into modules for better understanding of the
circuit.
       The modules included in this project are
                            Pic Embedded Microcontroller PIC 16F877
                            Battery for Power Supply
                            RFID Card Reader with cards
                            APR 9600 Voice Recording and Playback IC
                            Wireless RF Receiver unit
                            Wireless RF Transmitter unit
                            Software Driver in Hitech ‘C’ Language.


Pic Embedded Microcontroller (PIC 16F877):
This is the heart of the device which is responsible for sensing the obstacles
and producing voice Output.


RFID Card Reader with Cards
       A RFID Card reader is fixed on the unit. Cards will be placed on the path
at regular intervals. When the unit encounters a card, it can sense the point at
which the unit is present through the unique code present in the card.


APR 9600 Voice Recording and Play Back IC

       This IC is a Single Chip Voice Recording and Playback IC. A Prerecorded
Voice is Stored into the IC. It can be played again by the controller by sending a
control signal to the IC.
RF Wireless Transmitter and Receiver:
       A Wireless RF module is used to establish a wireless link between the unit
the PC. The frequency range is 433.92 and 315 MHZ.




Dijkstra's algorithm

       Conceived by Dutch computer scientist Edsger Dijkstra in 1959, is a graph
search algorithm that solves the single-source shortest path problem for a graph
with nonnegative edge path costs, producing a shortest path tree. This algorithm is
often used in routing. An equivalent algorithm was developed by Edward F.
Moore in 1957

For a given source vertex (node) in the graph, the algorithm finds the path with
lowest cost (i.e. the shortest path) between that vertex and every other vertex. It
can also be used for finding costs of shortest paths from a single vertex to a single
destination vertex by stopping the algorithm once the shortest path to the
destination vertex has been determined. For example, if the vertices of the graph
represent cities and edge path costs represent driving distances between pairs of
cities connected by a direct road, Dijkstra's algorithm can be used to find the
shortest route between one city and all other cities. As a result, the shortest path
first is widely used in network routing protocols, most notably IS-IS and OSPF
(Open Shortest Path First).

Algorithm

Let the node we are starting be called an initial node. Let a distance of a node Y
be the distance from the initial node to it. Dijkstra's algorithm will assign some
initial distance values and will try to improve them step-by-step.

   1. Assign to every node a distance value. Set it to zero for our initial node and
       to infinity for all other nodes.
   2. Mark all nodes as unvisited. Set initial node as current.
   3. For current node, consider all its unvisited neighbours and calculate their
       distance (from the initial node). For example, if current node (A) has
       distance of 6, and an edge connecting it with another node (B) is 2, the
       distance to B through A will be 6+2=8. If this distance is less than the
       previously recorded distance (infinity in the beginning, zero for the initial
       node), overwrite the distance.
4. When we are done considering all neighbours of the current node, mark it
                as visited. A visited node will not be checked ever again; its distance
                recorded now is final and minimal.
           5. Set the unvisited node with the smallest distance (from the initial node) as
                the next "current node" and continue from step 3.


                                     Block Diagram

     Power ON                                      RF Receiver       RF Transmitter
       LED                                                                                   Switches for
                              Alarm Output                                                   selecting
                                                                                             Destination




                                                                                       APR 9600 Voice IC
On OFF Switch                      Microcontroller PIC16F877

                                                                                Potential
                                                                                divider
                                                                                                   Speaker




                         RFID Card
Power supply              Reader                  Cards
unit                                                                        Intruder




                                          RF Receiver




                                          RF Transmitter

Mais conteúdo relacionado

Mais de ASHOKKUMAR RAMAR

FREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECE
FREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECEFREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECE
FREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECE
ASHOKKUMAR RAMAR
 
FREE INPLANT TRAINING ECE CHENNAI-T.NAGAR/KODAMBAKKAM
FREE INPLANT TRAINING ECE  CHENNAI-T.NAGAR/KODAMBAKKAMFREE INPLANT TRAINING ECE  CHENNAI-T.NAGAR/KODAMBAKKAM
FREE INPLANT TRAINING ECE CHENNAI-T.NAGAR/KODAMBAKKAM
ASHOKKUMAR RAMAR
 
FREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTS
FREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTSFREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTS
FREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTS
ASHOKKUMAR RAMAR
 
ECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAI
ECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAIECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAI
ECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAI
ASHOKKUMAR RAMAR
 
BEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSE
BEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSEBEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSE
BEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSE
ASHOKKUMAR RAMAR
 
INPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECE
INPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECEINPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECE
INPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECE
ASHOKKUMAR RAMAR
 
INTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANY
INTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANYINTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANY
INTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANY
ASHOKKUMAR RAMAR
 
INPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT MANUFACTURER CHENNAI
INPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT  MANUFACTURER CHENNAIINPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT  MANUFACTURER CHENNAI
INPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT MANUFACTURER CHENNAI
ASHOKKUMAR RAMAR
 
INPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERING
INPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERINGINPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERING
INPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERING
ASHOKKUMAR RAMAR
 

Mais de ASHOKKUMAR RAMAR (20)

BEST PROJECT CENTER IN TAMBARAM/TAMBARAM IEEEPROJECTS
BEST PROJECT CENTER IN TAMBARAM/TAMBARAM IEEEPROJECTSBEST PROJECT CENTER IN TAMBARAM/TAMBARAM IEEEPROJECTS
BEST PROJECT CENTER IN TAMBARAM/TAMBARAM IEEEPROJECTS
 
IEEE PROJECTS CENTER TAMBARAM/PALLAVARAM/CHROMPET- a zigbee based animal hea...
IEEE PROJECTS CENTER  TAMBARAM/PALLAVARAM/CHROMPET- a zigbee based animal hea...IEEE PROJECTS CENTER  TAMBARAM/PALLAVARAM/CHROMPET- a zigbee based animal hea...
IEEE PROJECTS CENTER TAMBARAM/PALLAVARAM/CHROMPET- a zigbee based animal hea...
 
mini projects center chennai-maastech electrical parameters in industries
mini projects center chennai-maastech electrical parameters in industriesmini projects center chennai-maastech electrical parameters in industries
mini projects center chennai-maastech electrical parameters in industries
 
mini projects titles for electronics engineering:design for visually impaired...
mini projects titles for electronics engineering:design for visually impaired...mini projects titles for electronics engineering:design for visually impaired...
mini projects titles for electronics engineering:design for visually impaired...
 
ieee projects titles for ece students contact maastech-+91 98402 34766
ieee projects titles for ece students contact maastech-+91 98402 34766ieee projects titles for ece students contact maastech-+91 98402 34766
ieee projects titles for ece students contact maastech-+91 98402 34766
 
latest ieee projects for ece-petrol bunk automation with prepaid cards and gs...
latest ieee projects for ece-petrol bunk automation with prepaid cards and gs...latest ieee projects for ece-petrol bunk automation with prepaid cards and gs...
latest ieee projects for ece-petrol bunk automation with prepaid cards and gs...
 
microcontroller projects center chennai -rfid projects & rfid applications
microcontroller projects center  chennai -rfid projects & rfid applicationsmicrocontroller projects center  chennai -rfid projects & rfid applications
microcontroller projects center chennai -rfid projects & rfid applications
 
best biomedical project center chennai- recent advances in wearable sensors f...
best biomedical project center chennai- recent advances in wearable sensors f...best biomedical project center chennai- recent advances in wearable sensors f...
best biomedical project center chennai- recent advances in wearable sensors f...
 
LATEST IEEE PROJECTS TITLES : personal lung function monitoring devices for a...
LATEST IEEE PROJECTS TITLES : personal lung function monitoring devices for a...LATEST IEEE PROJECTS TITLES : personal lung function monitoring devices for a...
LATEST IEEE PROJECTS TITLES : personal lung function monitoring devices for a...
 
IEEE PROJECTS ABSTRACT 2015-2016: model based mean arterial pressure estimation
IEEE PROJECTS ABSTRACT 2015-2016: model based mean arterial pressure estimationIEEE PROJECTS ABSTRACT 2015-2016: model based mean arterial pressure estimation
IEEE PROJECTS ABSTRACT 2015-2016: model based mean arterial pressure estimation
 
FINAL YEAR PROJECTS TITLES 2016-IEEE PAPER-MAASTECH CHENNAI
FINAL YEAR PROJECTS TITLES 2016-IEEE PAPER-MAASTECH CHENNAIFINAL YEAR PROJECTS TITLES 2016-IEEE PAPER-MAASTECH CHENNAI
FINAL YEAR PROJECTS TITLES 2016-IEEE PAPER-MAASTECH CHENNAI
 
FREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECE
FREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECEFREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECE
FREE INPLANT TRAIINING FOR ENGINEERING STUDENTS EEE/BIOMEDICAL/ECE
 
FREE INPLANT TRAINING ECE CHENNAI-T.NAGAR/KODAMBAKKAM
FREE INPLANT TRAINING ECE  CHENNAI-T.NAGAR/KODAMBAKKAMFREE INPLANT TRAINING ECE  CHENNAI-T.NAGAR/KODAMBAKKAM
FREE INPLANT TRAINING ECE CHENNAI-T.NAGAR/KODAMBAKKAM
 
FREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTS
FREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTSFREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTS
FREE INPLANT TRAINING CHENNAI FOR ENGINEERING STUDENTS
 
ECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAI
ECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAIECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAI
ECE INPLANT TRAINING ECE/ECE/ECE INPLANT TRAINING CHENNAI
 
BEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSE
BEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSEBEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSE
BEST INTERNSHIP TRAINING FOR ENGINEERING STUDENTS-CHENNAI-ECE/E&I/BIOMEDICAL/CSE
 
INPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECE
INPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECEINPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECE
INPLANT TRAINING FOR ENGINEERING STUDENTS CHENNAI-ELECTRONICS -ECE
 
INTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANY
INTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANYINTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANY
INTERNSHIP TRAINING CERTIFICATE CHENNAI-MAASTECH COMPANY
 
INPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT MANUFACTURER CHENNAI
INPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT  MANUFACTURER CHENNAIINPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT  MANUFACTURER CHENNAI
INPLANT TRAINING CERTIFICATE FOR INDUSTRY PRODUCT MANUFACTURER CHENNAI
 
INPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERING
INPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERINGINPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERING
INPLANT TRAINING FOR ECE/EEE/CSE/E&I/BIOMEDICAL ENGINEERING
 

Último

Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in DelhiRussian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
kauryashika82
 
Making and Justifying Mathematical Decisions.pdf
Making and Justifying Mathematical Decisions.pdfMaking and Justifying Mathematical Decisions.pdf
Making and Justifying Mathematical Decisions.pdf
Chris Hunter
 

Último (20)

2024-NATIONAL-LEARNING-CAMP-AND-OTHER.pptx
2024-NATIONAL-LEARNING-CAMP-AND-OTHER.pptx2024-NATIONAL-LEARNING-CAMP-AND-OTHER.pptx
2024-NATIONAL-LEARNING-CAMP-AND-OTHER.pptx
 
Measures of Central Tendency: Mean, Median and Mode
Measures of Central Tendency: Mean, Median and ModeMeasures of Central Tendency: Mean, Median and Mode
Measures of Central Tendency: Mean, Median and Mode
 
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in DelhiRussian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
 
Basic Civil Engineering first year Notes- Chapter 4 Building.pptx
Basic Civil Engineering first year Notes- Chapter 4 Building.pptxBasic Civil Engineering first year Notes- Chapter 4 Building.pptx
Basic Civil Engineering first year Notes- Chapter 4 Building.pptx
 
Energy Resources. ( B. Pharmacy, 1st Year, Sem-II) Natural Resources
Energy Resources. ( B. Pharmacy, 1st Year, Sem-II) Natural ResourcesEnergy Resources. ( B. Pharmacy, 1st Year, Sem-II) Natural Resources
Energy Resources. ( B. Pharmacy, 1st Year, Sem-II) Natural Resources
 
microwave assisted reaction. General introduction
microwave assisted reaction. General introductionmicrowave assisted reaction. General introduction
microwave assisted reaction. General introduction
 
Food Chain and Food Web (Ecosystem) EVS, B. Pharmacy 1st Year, Sem-II
Food Chain and Food Web (Ecosystem) EVS, B. Pharmacy 1st Year, Sem-IIFood Chain and Food Web (Ecosystem) EVS, B. Pharmacy 1st Year, Sem-II
Food Chain and Food Web (Ecosystem) EVS, B. Pharmacy 1st Year, Sem-II
 
Mehran University Newsletter Vol-X, Issue-I, 2024
Mehran University Newsletter Vol-X, Issue-I, 2024Mehran University Newsletter Vol-X, Issue-I, 2024
Mehran University Newsletter Vol-X, Issue-I, 2024
 
Application orientated numerical on hev.ppt
Application orientated numerical on hev.pptApplication orientated numerical on hev.ppt
Application orientated numerical on hev.ppt
 
Sociology 101 Demonstration of Learning Exhibit
Sociology 101 Demonstration of Learning ExhibitSociology 101 Demonstration of Learning Exhibit
Sociology 101 Demonstration of Learning Exhibit
 
TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...
TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...
TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...
 
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Mixin Classes in Odoo 17  How to Extend Models Using Mixin ClassesMixin Classes in Odoo 17  How to Extend Models Using Mixin Classes
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
 
ComPTIA Overview | Comptia Security+ Book SY0-701
ComPTIA Overview | Comptia Security+ Book SY0-701ComPTIA Overview | Comptia Security+ Book SY0-701
ComPTIA Overview | Comptia Security+ Book SY0-701
 
Micro-Scholarship, What it is, How can it help me.pdf
Micro-Scholarship, What it is, How can it help me.pdfMicro-Scholarship, What it is, How can it help me.pdf
Micro-Scholarship, What it is, How can it help me.pdf
 
Measures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SDMeasures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SD
 
This PowerPoint helps students to consider the concept of infinity.
This PowerPoint helps students to consider the concept of infinity.This PowerPoint helps students to consider the concept of infinity.
This PowerPoint helps students to consider the concept of infinity.
 
Making and Justifying Mathematical Decisions.pdf
Making and Justifying Mathematical Decisions.pdfMaking and Justifying Mathematical Decisions.pdf
Making and Justifying Mathematical Decisions.pdf
 
Introduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The BasicsIntroduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The Basics
 
Unit-V; Pricing (Pharma Marketing Management).pptx
Unit-V; Pricing (Pharma Marketing Management).pptxUnit-V; Pricing (Pharma Marketing Management).pptx
Unit-V; Pricing (Pharma Marketing Management).pptx
 
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
 

ECE PROJECTS ABSTRACT-Assisting blind person using dijkstra's shortest path algorithm

  • 1. Assisting Blind person using DIjkstra’s shortest path algorithm This Project comprises of a Hardware mechanical model which is controlled by the electronic circuits to assist a blind person. I.e., This mechanical model is attached with the walking stick of the blind person. The model will move automatically. This model helps the blind person to reach the destination quickly. The model has a wireless link to a nearby computer system through which it can identify the shortest path. When the source and destination is selected the unit will send the data to the computer. The computer will calculate the shortest path using Dijkstra’s shortest path algorithm and transfers the route to the unit. The unit will then tell the user to move in which direction. The movement of the user in ensured using a RFID proximity cards and a reader. The reader will be placed on the unit and on encountering of cards (Cards placed at each point) will tell the user has to take right or left or straight through voice output. An APR 9600 voice storage and retrival IC is used for this purpose. The unit will give alarm signal when it finds a Obstacle. This project is divided into modules for better understanding of the circuit. The modules included in this project are Pic Embedded Microcontroller PIC 16F877 Battery for Power Supply RFID Card Reader with cards APR 9600 Voice Recording and Playback IC Wireless RF Receiver unit Wireless RF Transmitter unit Software Driver in Hitech ‘C’ Language. Pic Embedded Microcontroller (PIC 16F877):
  • 2. This is the heart of the device which is responsible for sensing the obstacles and producing voice Output. RFID Card Reader with Cards A RFID Card reader is fixed on the unit. Cards will be placed on the path at regular intervals. When the unit encounters a card, it can sense the point at which the unit is present through the unique code present in the card. APR 9600 Voice Recording and Play Back IC This IC is a Single Chip Voice Recording and Playback IC. A Prerecorded Voice is Stored into the IC. It can be played again by the controller by sending a control signal to the IC. RF Wireless Transmitter and Receiver: A Wireless RF module is used to establish a wireless link between the unit the PC. The frequency range is 433.92 and 315 MHZ. Dijkstra's algorithm Conceived by Dutch computer scientist Edsger Dijkstra in 1959, is a graph search algorithm that solves the single-source shortest path problem for a graph with nonnegative edge path costs, producing a shortest path tree. This algorithm is
  • 3. often used in routing. An equivalent algorithm was developed by Edward F. Moore in 1957 For a given source vertex (node) in the graph, the algorithm finds the path with lowest cost (i.e. the shortest path) between that vertex and every other vertex. It can also be used for finding costs of shortest paths from a single vertex to a single destination vertex by stopping the algorithm once the shortest path to the destination vertex has been determined. For example, if the vertices of the graph represent cities and edge path costs represent driving distances between pairs of cities connected by a direct road, Dijkstra's algorithm can be used to find the shortest route between one city and all other cities. As a result, the shortest path first is widely used in network routing protocols, most notably IS-IS and OSPF (Open Shortest Path First). Algorithm Let the node we are starting be called an initial node. Let a distance of a node Y be the distance from the initial node to it. Dijkstra's algorithm will assign some initial distance values and will try to improve them step-by-step. 1. Assign to every node a distance value. Set it to zero for our initial node and to infinity for all other nodes. 2. Mark all nodes as unvisited. Set initial node as current. 3. For current node, consider all its unvisited neighbours and calculate their distance (from the initial node). For example, if current node (A) has distance of 6, and an edge connecting it with another node (B) is 2, the distance to B through A will be 6+2=8. If this distance is less than the previously recorded distance (infinity in the beginning, zero for the initial node), overwrite the distance.
  • 4. 4. When we are done considering all neighbours of the current node, mark it as visited. A visited node will not be checked ever again; its distance recorded now is final and minimal. 5. Set the unvisited node with the smallest distance (from the initial node) as the next "current node" and continue from step 3. Block Diagram Power ON RF Receiver RF Transmitter LED Switches for Alarm Output selecting Destination APR 9600 Voice IC On OFF Switch Microcontroller PIC16F877 Potential divider Speaker RFID Card Power supply Reader Cards unit Intruder RF Receiver RF Transmitter