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WIRELESS SECURITY SYSTEM

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Contain small amount of radioactive Americium-241 and 2 metal plates carry opposite charges. Americium-241 emits alpha particle. Motion Sensor ... – PowerPoint PPT presentation

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Title: WIRELESS SECURITY SYSTEM


1
WIRELESS SECURITY SYSTEM
  • Group 2
  • Hai Vo
  • Tan Tran
  • Tam Nguyen
  • Tuan Nguyen

2
Objectives
  • The purpose of the wireless security system is to
    protect buildings or properties which are located
    outside the owner house.
  • The system must be
  • Reliable
  • Easy to install
  • Easy to use

3
Block Diagram
Sensing Unit Contain sensor and IR
transmitter Remote Unit Contain IR receiver and
RF transmitter Central Unit Contain RF receiver
and microcontroller
4
Hardware Specification
  • Central unit can detect signal from up to 5
    remote units, located up to 300 feet from the
    central unit.
  • System can detect smoke, motion, door open, and
    glass break.
  • Each remote unit can have many sensing units
  • Alarm has 3 modes
  • No sound and green light for OK
  • Intermittent and yellow light for low battery
  • Continuous and red light for panic events
  • The sound must be greater than 100 dB
  • Power supply 110V AC 60 Hz for central unit
    and 9V battery for remote units
  • Communication between remote units and central
    unit FM radio at 418 MHz to 432 MHz.
  • Communication between sensing units and remote
    units Infrared transmission.
  • Communication between central unit and computer
    serial port.

5
Software Specification
  • Database will be updated every time an event
    occurs.
  • Information -- including occurring event, date,
    time, and location -- can be kept for at least 10
    years
  • Software is able to report the system history
    when the user request it.
  • Software is able to send email or make a phone
    call automatically when a critical event occurs.

6
SENSING UNITS
  • Tam Nguyen

7
Photoelectric Smoke Sensor
Smoke-free Condition
Smoke Condition
  • Light beam moves in straight line, no light
    strikes the photocell
  • ? No current
  • Light is deflected by smoke particle and
    strikes the photocell
  • ? Photocell generates current

8
Ionization Smoke Sensor
Contain small amount of radioactive Americium-241
and 2 metal plates carry opposite charges.
Americium-241 emits alpha particle.
  • Normal condition
  • Alpha particles collide with air to produce
    charged ions.
  • () particles move to (-) plate
  • (-) particles move to () plate
  • Steady flow of ions ? steady current
  • Smoke condition
  • Smoke particles combine with charged ions and
    restore to neutral
  • This reduces the flow of electricity below the
    threshold ? trigger alarm

9
Motion Sensor
  • Fact Human body heat is radiated at the infrared
    wavelength
  • Infrared sensor can be used to detect the present
    of a person
  • Two types of infrared sensors
  • Passive infrared sensor
  • Active infrared sensor

10
Active Infrared Sensor
  • Problem
  • Hard to install
  • The sensor will not work if dust covers the
    reflector
  • IR transmitter and receiver are encased in a
    single unit.
  • IR transmitter sends signal to the reflector
  • The reflector reflects the signal back to the
    receiver.
  • If the IR beam is cut, then the sensor will
    trigger the alarm

11
Passive Infrared Sensor
  • Consist of Lead Zirconate Titanate plate, which
    is sensitive to the infrared light.
  • Positive electric charge on one surface and
    negative charge on the other.
  • Normal condition, charges on two side are
    balanced
  • When infrared ray shines on the surface, the
    charges are disordered and output voltage is
    generated

12
Passive Infrared Sensor (cont.)
  • Problem False alert caused by white ambient
    light
  • Solution Use two pieces of sensors
  • If both sensors detect the same radiation, then
    the voltage difference is zero.
  • When a person is moving in the monitored region,
    radiations detected are not the same and the
    voltage difference are not the zero.

13
Component
  • PIR325 from Glolab Corp.
  • Two elements
  • Spectral response 5 14µm
  • Output Voltage 20 mV
  • Supplied Voltage 2.5 15 V
  • Price 4.00

Reprinted with permission of Glolab
14
Door Open Sensors
  • Mechanical Switch
  • Use spring-loaded to trigger the switch when the
    door is opened.
  • Easy to defeat if using a stick to hold the
    spring
  • Magnetic Switch
  • Consist of a magnet and a magnetically operated
    switch.
  • When the door is closed, the magnet pulls the
    switch to the normal position.
  • When the door is opened, the magnet releases the
    switch
  • Advantage Higher security level than mechanical
    switch

15
Component
Mss100-7 Balanced Magnetic Switch Reprinted with
permission of Flair Electronic
16
Glass Break Sensors
  • Acoustic Sensor
  • Use an acoustic processor to generate output
    voltage when high frequency created by the
    shattering impact on the glass is detected
  • Disadvantage
  • Difficult to implement
  • High cost
  • Easy to be defeated by distorting the sound of
    breaking glass.
  • Shock Sensor
  • Use ceramic disc laminated to a metal disc, which
    produces voltage proportional to an impact or
    vibration
  • Advantage
  • Reliable
  • Hard to be defeat
  • Low cost

17
Component
  • Piezo-electric Shock Sensor PKS1-4A1
  • From Maruta
  • Compact and light-weighted design

Reprinted with Permission of Maruta
18
Standardizing Output Signal from Sensor
  • Output voltages from sensors are very small
    amplitude and may not be appropriate for
    processing.
  • Need circuits to
  • Amplify the voltage signal,
  • Scaling the voltage signal to an appropriate
    range
  • Block diagram

Sensor
Amplifier
Scaling circuit
5V Output
19
Amplifier
  • Using Op-amp to amplify voltage
  • Basic Circuit
  • Gain Av Vo/Vi
  • - R2/R1
  • Using 2 or 3 op-amp in series to obtain a big
    gain
  • Av Vo/Vi (R2R4)/(R3R1)

20
Scaling Circuit
  • Using comparator to scale the voltage signal
  • Basic Circuit
  • Vi lt Vref, then Vo 0V
  • Vi gt Vref, then Vo 5V

21
Infrared Transmitter and Receiver
  • Tuan Nguyen

22
Infrared Transmitters/Receivers
  • Purpose Transfer signals from sensing units to
    remote units.
  • Specification
  • Amplitude of signal 5V amplitude
  • Frequency of signal
  • Smoke sensing unit 10 KHz
  • Motion sensing unit 1 KHz
  • Door open sensing unit 100 KHz
  • Glass break sensing unit100 KHz
  • Maximum distance 20 ft

23
Block Diagram of IR Transmitter
  • When signal from sensor is a logic 0, the IR LED
    will not emit signal
  • When signal from sensor is a logic 1, the IR LED
    will emit IR signal. The frequency of the signal
    depends on the frequency of the oscillator.

signal from sensors
Oscillator
24
Oscillator
  • Using 555 timer
  • Basic circuit

Example Ra 100 ohm, Rb 7.165 Kohm, and C
10nF then f
1KHZ and duty cycle 50
25
Complete Circuit of Motion Sensing Unit
Scaling Circuit
Motion Sensor
Amplifier
Oscillator
26
Block Diagram of IR Receiver
  • Active filters will pass signals of appropriate
    frequency.
  • There are 3 kinds of filters
  • Low pass filter pass signal of frequency of 1KHz
    sent by motion sensing unit.
  • Band pass filter pass signal of frequency of
    10KHz sent by smoke sensing unit.
  • High pass filter pass signal of frequency of
    100KHz sent by door open and glass break sensing
    units.

27
Low Pass Filter and Simulation Result
28
Band Pass Filter and Simulation Result
R1 R2 1.33 K? C1 0.01µF C2 0.013µ F
29
High Pass Filter and Simulation Result
C 1nF and R1 R2 1.6K?
30
An Example of Receiver Circuit
31
RF TRANSMISSION
  • Hai Vo

32
Data Encoder
  • Data received in parallel form
  • Data transmitted in serial form
  • Need an encoder
  • To convert data from parallel to serial
  • To filter unwanted signal (noise)

33
GL-104 Encoder/Decoder
  • Produced and marketed by Glolab
  • Can be configured as encoder or decoder.
  • Price is cheap 4.82/chip
  • 4 inputs and 4 outputs
  • 4 address lines ? 16 addresses
  • Type of output Momentary or latch

34
Configuring GL-104

35
Addressing a Unit
  • 4 address lines ? 16 address
  • Using DIP switch to set the address

36
Triggering a Transmission
  • Logic high (5V) must be applied to the transmit
    enable pin of the GL-104

37
Resonator and Voltage Detector Reset
  • Resonator
  • To generate clock frequency
  • Synchronize the serial data transmission
  • Component 4MHz ceramic resonator CR4 from Glolab
    Corp.
  • VDR
  • Prevent data loss in case the power supply drops
    momentarily
  • Component TO92 from Glolab Corp.

38
Complete Encoder Configuration
39
RF Transmitter
  • TM1V from Glolab
  • Size 0.7x0.6
  • Price 16.40
  • Speed 4,800 bits/sec
  • Frequency 418 MHz
  • Range gt300 ft

Reprinted with Permission of GLolab
40
Complete Circuit of RF Transmission
41
RF Receiver
  • RM1V from Glolab
  • Size 0.9x0.85
  • Price 23.75
  • Speed 4,800 bits/sec
  • Frequency 418 MHz
  • Compatible with TM1V transmitter

Reprinted with Permission of GLolab
42
Complete Circuit of RF Receiver
43
Software and Data Decoding
  • Tan Tran

44
MC68HC11 by Motorola
  • 8-bit microcontroller
  • 256 bytes SRAM
  • 512 bytes EEPROM
  • 8-KB ROM
  • Serial Communication Interface
  • 4 Registers A, B, X and Y
  • 40 I/O pins
  • Price 112

45
Transferring Data from Decoder to Microcontroller
  • Connect data and address lines from GL-104
    decoder to port C of MC68HC11
  • Writing assembly code to read and decode data.

46
Algorithm of Decoding Data
  • 1004 Address of I/O port B
  • 1000 Address of I/O port A
  • 1008 Address of I/O port D

Address
Data
47
Visual Alarm of the Central Unit
48
Serial Communication Interface (SCI)
  • To connect microcontroller to the computer.
  • SCI and RS232 incompatible
  • SCI 0 and 5V represent logic 0 and 1
  • RS232 -3V to 3V is undefined
  • Solution Using MAX232 chip to convert 0 and 5V
    inputs to 10V and -10V outputs.
  • Circuit

49
Security Monitoring Software
  • Tan Tran

50
Why Java
  • Fully Object-Oriented language
  • Platform independence
  • Java is free distributed by Sun Microsystem
  • Free tutorials and free e-books
  • Provides a lot of packages to deal with practical
    problems

51
Java Serial Port Communication
  • Purpose To read data from microcontroller
    through the serial port
  • Tool Javax.comm package by Javasoft.
  • Allow the computer to communicate with external
    devices connected to the serial port
  • Compatible with RS232 standard
  • Classes to deal with serial communication
  • CommPortIdentifier Open port.
  • Javax.comm.CommPort Input and Output stream
  • Javax.comm.SerialPort Interactions with serial
    ports

52
Algorithm of Serial Port Communication
53
Database Management System
  • Data Source Using mySQL
  • Application Using Java Database Connection
    (JDBC)
  • Advantage
  • Database is independent from application
  • Portable database transition

54
Information Stored in Database
  • Every time an event occurs, java program will
    automatically create a record, connect to the
    database, and update the database
  • Information in the database
  • Date and time when an event occurs
  • Location where the event occurs
  • Location information

55
Graphical User Interface
56
Making a Phone Call Using Java Telephony API
  • Purpose To make a phone call to predefined
    people when a critical event occurs.
  • Java Telephony API (JTAPI)
  • Allow user to make phone calls directly from
    computers
  • Observe and manage incoming calls
  • Problem Must have service provider Server,
    telephone card, or computer networking.

57
Algorithm of Making a Phone Call
  • 5 steps to implement a phone call using JTAPI
  • Get provider
  • Get address (phone number)
  • Create a phone call
  • Place the call
  • Observe the call

58
Graphical User Interface
59
Sending Email Using Javamail API
  • Purpose To send emails automatically to
    predefined address when a critical event occurs.
  • Javamail API
  • Be able to send and receive emails from Java
    application or applet.
  • Be able to attach files and manage folders
  • Why dont we use current available email?
  • It requires user interaction.

60
Algorithm of Sending Email Using Javamail API
  • 4 basic steps
  • Create a session object
  • Create and put text into message object
  • Set the attribute of the message
  • Send the message

61
An Email Example
62
Administration
  • Tuan Nguyen

63
Work Division
  • Tam Nguyen Sensors
  • Tuan Nguyen IR transmitter/receiver
  • Hai Vo RF Transmitter/Receiver
  • Tan Tran Data decoding and software

64
Prototype Procedure
  • Step 1
  • Build and test sensors. Make sure output signals
    from sensors are 5V (logic 1)
  • Build and test IR transmitter/ receiver assuming
    the input is 5V. Receiver must distinguish
    signals from different sensing units
  • Build and test RF transmitter/ receiver.
  • Write java programs and assembly code to decode
    data
  • Step 2 Integration and testing the whole system

65
Project Milestone
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