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VIVEKANAND EDUCATION SOCIETY’S POLYTECHNIC
CHEMBUR,MUMBAI-400071
INFRA RED BASED SECURITY CONTROL SYSTEM
A PROJECT REPORT
Submitted by
AKSHAY BHOPANI
AADITYA AUROBINDO
VIJAYA KAMBLE
ATUL MALUSARE
SAURAB KADAM
In partial fulfillment for the award of the degree
Of
DIPLOMA IN
ELECTRONICS & TELECOMMUNICATION ENGINEERING
Guided by
MS. PRAJAKTA KALE
ACKNOWLEDGEMENT
With a sense of gratitude and respect, I would like to extend my
heartiest thanks to my guide Ms. Prajakta Kale for her genuine
interest and constant motivation during the entire project duration .
I think her for her highly innovative suggestion and active and
dedicated involvement throughout the work.
I am also thankful to Mr.VikrantJoshi,Principle,V.E.S.Polytechnic
for his constant encouragement throughout the course of project
work.
Lastly , but the most important of all I would like our Lab Assistant
Mr.Dinesh Sir for his constant support. He helped us totally in our
project work.
CONTENTS
List of Figures
List of Tables
ABSTRACT
1.INTRODUCTION
1.1 Timer technology
1.2 IR technology
1.3 Objective of the study:
1.4 Review of the project:
2.DIAGRAMATIC DESCRIPTION
2.1 BLOCK DIAGRAM
3.CIRCUIT DIAGRAM
3.1 Circuit diagram
3.2 Circuit Diagram Working
4.LISTS OF COMPONENTS AND DESCRIPTION
4.1 Components List
4.2 DESCRIPTION OF COMPONENT
4.2.1 IC 555
5.PCB MAKING
5.1 Printed Circuit Board
5.2 PCB Layout Designing
5.3 Making Layout Using EAGLE
5.4 PCB Designing Rules
5.5 PCB Etching
5.6 PCB Drilling
5.7 Drilling Process
5.8 Soldering
5.9 Cold Solder Joints
5.10 Top View of Board
5.11 PCB Layout
6. ALGORITHM, FLOWCHART & PROGRAMMING
6.1 ALGORITHM
6.2 FLOWCHART
6.3 PROGRAMMING
7. TROUBLESHOOTING AND TESTING
7.1 Troubleshooting
7.1.1 Need of Troubleshooting
7.1.2 Steps prior to troubleshooting
7.1.3 Troubleshooting Steps
7.2 TROUBLESHOOTING OF OUR PROBLEMS
8. MERITS , DEMERITS , APPLICATIONS AND FUTURE
IMPROVEMENTS
8.1 Merits
8.2 Demerits
8.3 Applications
8.4 Future Improvements
CONCLUSION
BIBLIOGRAPHY
List of Figures
Figure2.1: Block Diagram of Project
Figure3.1: Circuit diagram
Figure5.2: Cleaning of PCB
Figure5.3: Dip coat
Figure5.4: PCB Oven
Figure5.5: UV Exposer
Figure5.6: Agitating PCB
Figure5.7: Easy Etcher
Figure5.10: Top view of board
Figure5.11: PCB Layout of project
List of Tables
Table 4.1: Component list
ABSTRACT
The novel idea of this project is to provide a cheap and reliable security system using infra
red. Also in this project we will be providing live streaming of videos of the area protected
by our security system. Here we use mobile phones as a web cam for live streaming videos.
It is based on the motion detection and control system action principle.
As soon as motion is detected the control system will take appropriate action.
It will make home light blink and buzzer activation.
Doors would be closed automatically and theft seen would be captured in image.
An automatic sms would be send to defined number.
So in this way full security will be maintained.
It is based on following principle –
1- It is used to sense intrusion.
2- When there is no intrusion the output is low.
3- When there is intrusion the output is high.
4- To indicate intrusion we can connect any circuit.
CHAPTER 1
INTRODUCTION
1.1 Timer technology
This integrated circuit is used for timing. Many circuits are composed of timers and the
most common of them all is the 555 Integrated Circuit. It is used in many commercially
manufactured items such as video recorders and timers.You must understand the basic
workings of this important IC. The 555 has eight pins (legs) but the function of two are
very important. These are pin two and three. This chip is used in timing circuits. It is a
timer. When the switch is pressed a current / voltage goes into the IC through pin two (the
input pin). The chip starts counting and when it has finished counting it ‘pulses’ a current
or voltage from pin three (the output pin). This voltage from pin three switches a transistor
and allows the LED to light.The time from pressing the switch to the LED lighting could be
anything from 1 second to twenty minutes.
A 555 will switch on a range of components not only LEDs. For example, it can switch on a
relay which then allows a second circuit to work.The circuit shown opposite is a simple
version of a real 555 circuit. The real circuit includes resistors and capacitors. (See
following sheets).The 555 integrated circuit acts as a counter. When activated by current
entering in through pin 2, it starts to count for a certain amount of time. When it has
finished counting it emits current from pin 3. This usually activates other components such
as LEDs or relays.When the push switch is pressed it allows current to flow into pin 2,
starting the timing sequence.
The combination of the resistor and capacitor determines the length of the timing sequence.
In general terms, if the resistor and capacitor values are high the timing sequence is long. If
the values are low the timing sequence is short.
The transistor acts as a very sensitive switch. When current enters the base electricity can
flow from the collector to the emitter. this allows the LED light.The LED lights when
current flows through it. In this circuit it indicates when pin three is emitting current.
1.2 IR technology
Infrared (IR) technology addresses a broad variety of wireless applications, especially in the
areas of sensing and remote control. Today’s newest products, such as cell phones, digital
cameras, and DVD players as well as remote controls for every market segment, rely on IR
sensing and control devices. For more than 40 years, ROHM Semiconductor has been driving
technology advances that have led to a growing number of IR sensing and communication
applications.
To understand infrared technology, the best starting point is the electromagnetic spectrum.
The frequency range and wavelengths of the entire spectrum are shown in Figure 1. The IR
portion of the electromagnetic spectrum is usually divided into three regions: the near-, midand far- infrared. The wavelengths for these regions are shown in Table 1. Infrared
wavelengths range from red to violet. The frequencies are higher than microwave but shorter
than visible light.
Focusing on near-infrared devices and applications, PhotoOptic technologies are used for
optical sensing and optical communications with numerous general market applications,
since light is less complex than RF when implemented as the signal source. Optical sensors
are used in industrial, consumer and other applications for sensing movement, position,
proximity, ambient light, speed, and direction.
Optical wireless communication uses IR data transmission for short range applications,
such as computer peripherals and PDAs (personal digital assistants). For optical
communication, a modulated IR light beam transmitted by an emitter LED is received by a
silicon photodiode. Infrared Data Association (IrDA) standards provide the protocol for
these types of communication. Since IR does not penetrate walls, it does not interfere with
other signals in indoor environments. IR technology is the most commonly used technique
for remotely controlling appliances.
Some general applications for IR components include:







Office Automation (OA) equipment such as copiers, fax machines, and printers
Vending machines
Gaming products
Home entertainment products
Medical / health care equipment
Banking terminals such as ATMs
Testing equipment such as IC/LSI testers, encoders, and more
Types of IR devices
To address the variety of sensing applications, products take advantage of several IR
technologies including:






IR Emitters
IR Receivers (sensors)
Photointerrupters and Photo Reflectors
Tilt Sensors
IrDA Communication Modules
Remote Control Module Receivers
A brief explanation of each shows the commonalities and differences.
An IR Emitter is a light emitting diode (LED). Different types of IR LEDs are specified
based on their packaging.IR Receivers are also called sensors since they detect the
wavelength and spectral radiation of the light from the IR emitter. IR receivers are
specified by optic features, packaging, special circuitry such as an ambient light filter, wide
viewing angle, and more.
As a wireless technology, IR has advantages and disadvantages when compared to RF and
industrial, scientific, and medical (ISM) (902-928 MHz) band technologies. Advantages
include:
1. Higher security: beam directionality helps ensure that data isn’t detected or leaked
to nearby devices as it’s transmitted
2. High noise immunity: not as susceptible to signal interference from other devices
3. Few international regulatory constraints
4. Relatively low power requirements: ideal for laptops, cell phones, and personal
digital assistants
5. Simple design implementation
1.3 Objective of the study:
The main objective of this selecting project is to gain knowledge and experience in
developing a real time application. Apart from this, to gain the knowledge of Ne555 timers,
IR transmission and reception and the way in which videos can be live streamed.
1.4 Review of the project:
Many books have provided valuable information that was very useful for this project. One
such book authored byRamakantGayakwadtitled “Op-Amps and Linear Integrated Circuit”.
CHAPTER 2
2.1 BLOCK DIAGRAM
Our project aims at displaying messages on a LCD by sending messages through a mobile
which are transmitted on the lcd through the GSM Module. We know the objective of our
project, so we would now proceed to the block diagram of our project which will give us the
operation and clear explanation of the signal flow.
CHAPTER 3
CIRCUIT DIAGRAM
3.1 Circuit Diagram
As we have already gone through the operation of project with the help of block diagram.
Now let us have a view of the circuit diagram of our project.
3.1.1 IR Transmitter and Reciev
3.1.2 LED Flasher
3.2 Circuit diagram working
3.2.1 IR Motion detector
Here is the circuit diagram of an infrared motion detector that can be used to sense
intrusions. Infrared rays reflected from a static object will be in one phase, and the
rays reflected from a moving object will be in another phase. The circuit uses this
principle to sense the motion.
The IC1 (NE 555) is wired as an astablemultivibrator. The IR diode connected at the
output of this IC produces infrared beams of frequency 5Khz. These beams are
picked by the infrared sensor, photo transistor Q1. At normal condition, that is, when
there is no intrusion the output pin (7) of IC2 will be low. When there is an intrusion
the phase of the reflected waveforms has a difference in phase and this phase
difference will be picked by the IC2. Now the pin 7 of the IC 2 goes high to indicate
the intrusion. An LED or a buzzer can be connected at the output of the IC to indicate
the intrusion.
3.2.2 LED flasher
This circuit uses the 555 timer in an Astable operating mode which generates a
continuous output via Pin 3 in the form of a square wave. This turns the LED (D1) on
and off. The speed at which the LED (D1) Parts List
1x - NE555 Bipolar Timer
1x - LED (Red)
1x - 470K Resistor (1/4W)
2x - 1K Resistor (1/4W)
1x - 1F Electrolytic Capacitor (16V)
1x - 9V Voltage Battery is turned on and off is set by the values of R1 and R2
CHAPTER 4
LISTS OF COMPONENTS & DESCRIPTION
4.1 Component List
SR. NO.
1
2
3
4
5
6
7
8
9
10
TOTALRs. 302
Product Name
Resistor
10k ohms
50k ohms
470k ohms
22k ohms
220 ohms
33 ohms
2.2k ohms
1k ohms
Capacitors
1 uf
0.1 uf
0.01 uf
o.47 uf
Diodes
IN 4148
IN 4001
1N 4007
IC 555
L14F
LM1458
LED
IR LED
12*12 PCB board / clad
Jumper connectors wires
Product cost * Quantity
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
1*1
5*3
80*1
10*2
1*3
10*2
85*1
8*8
4.2 DESCRIPTION OF COMPONENT
4.4.1 IC 555
The LM555 is a highly stable device for generating accurate
time delays or oscillation. Additional terminals are provided
for triggering or resetting if desired. In the time delay mode of
operation, the time is precisely controlled by one external resistor and capacitor. For astable operation as an oscillator,
the free running frequency and duty cycle are accurately
controlled with two external resistors and one capacitor. The
circuit may be triggered and reset on falling waveforms, and
the output circuit can source or sink up to 200mA or drive
TTL circuits.
Features
1.Direct replacement for SE555/NE555
2.Timing from microseconds through hours
3.Operates in both astable and monostable modes
4,Adjustable duty cycle
5,Output can source or sink 200 mA
6,Output and supply TTL compatible
7,Temperature stability better than 0.005% per ̊C
8,Normally on and normally off output
9,Available in 8-pin MSOP package
Applications
Applications
1.Precision timing
2Pulse generation
3.Sequential timing
4.Time delay generation
5.Pulse width modulation
6.Pulse position modulation
7.Linear ramp generat
CHAPTER 5
PCB MAKING
5.1 Printed Circuit Board
Description:
A printed circuit board is used to mechanically & electrically connect electrical
components using conductive pathways, tracks traces etched from copper sheets laminated
on to conductive substrate.
As such, most of today’s PCB is not pushing, if nor exceeding, the limits of classic board
design. In mobile telecom for example, interconnect and board dimension are shrinking
rapidly, while designs are utilizing fewer, but more complex (and higher pin-count)
components. At the same time, boards for networking and computer are getting larger,
with more interconnect and plane layers.
In order to produce higher quality, more complex products, quicker and more cost
efficiently than their competition, companies are taking inventory of their PCB design
tools. Understanding which tools best support the needs of design teams is key to
determining the proper infrastructure investment, required services, support structure and
intellectual skill set of the company. Advanced functionality already exists in today’s
leading design tools to solve current and future design challenges. Therefore, companies
effectively utilizing the proper design tools have an advantage over those companies using
dated technology to design their boards-the inherent ability to automatically solve design
challenges without workarounds or short term, inefficient solutions.
PCB Materials:
Laminate materials:
•
•
FR-4, the most common PCB material.
FR-2
•
Composite epoxy material, CEM-1,5
•
Polyimide.
•
BT-epoxy.
•
Cyan ate Ester.
•
PTFE, Polytetrafluoroethylene(Teflon)
•
Conductive ink
•
Heavy copper
5.2 PCB Layout Designing
PCB LAYOUT SOFTWARES:
•
Altium Designer by Altium Limited
•
Autotrax
•
EAGLE by Cad Soft
•
Dip Trace by Novarm
•
Edwinxp
•
Free PCB by Allan Wright(open-source Ein2k/XP)
•
Free routing by alfonswirtz
•
Cadstar by zuken
•
CR5000 by zuken
•
Multisim
•
Geda, open source PCB software project
•
OrCAD by cadence
•
Allergo by cadence
•
TARGET 3001!
•
Kicad, open source suite
•
PADS by mentor graphics
•
PCB123 design by sunstone circuits
•
Proteus
•
Board station by mentor graphics
•
Expedition enterprise by mentor graphics
5.3 Making Layout Using EAGLE
Here is the procedure of designing the layout using eagle software:
•
Setting up initial settings: this stage of pcb designing involves setting up snaps
and visble grid. At this stage the default track and pad sixe should be set.
•
Set the mechanical elements of the pcb design: It is necessary to import the
details for the circuit board outline into the pcb layout software program as soon
as possible. It is also necessary to set up any reference marks and holes. These
may be required for pick and place machines, of test fixtures during the
production process.
•
Putting all components on the board: At this stage of the pcb layout, the
components need to be placed onto the printed circuit board so that they are
available to be moved and set I place later.
•
Creating functional building blocks: At this stage of pcb layout, the components
should be moved into their functional blocks so that associated components are
close to each other and the circuit can be routed easily later.
•
Identifying and routing layout critical tracks: Any tracks that are layout critical
shoukd be identified and then routed as they are required. By routing these
tracks at this stage, then the remained of the design can be implemented around
these tracks rather than trying to resolve problems later in the pcb layout.
•
Routing power and earth rails: Often the earth and power rails may be included
as planes, occupying a complete layer of the printed circuit board. This has
significant advantage not only in terms of enabling the higher levels of current to
be routed easily, but it also significantly reduces any problem with interference
on the printed circuit board.
•
Routing the remaining lines: Usually it is necessary to use the auto-route
function on the pcb layout software, it is normal to use the auto-route function’s
this may save many days trying to rout the pcb layout manually.
•
Manually routing any final line on the pcb layout: After the pcb layout software
has completed the auto-ranging, there may be routed manually. Alternatively if
the design has become too complicated for the space and available numbers of
layers, it may be necessary to make some fundamental changes to the board.
•
Undertaking final tidy up: Once all the design rules should have been followed
during the design, it is necessary to do a final check. It is better to catch any
problems at this stage rather than once a prototype pcb has been made. Thus we
completed the pcblayout designing process.
5.4 PCB Designing Rules
•
While designing a layout, it must be noted that size of the board should be
as small as possible.
2. Before starting, all components should be placed properly so that an accurate
measurement of space can be made.
3. The component should not be mounted very close to each other or far away
from one another and neither one should ignore the fact that some component
need ventilation, which considerably the dimension of the relay and transformer
in view of arrangement, the bolting arrangement is also considered.
4. The layout is first drawn on paper then traced on copper plate which finalized
with the pen or permanent marker which is efficient and clean with etching.
5. The resistivity also depends on the purity of copper, which is highest for low
purity of copper. The high resistance paths are always undesired for soldered
connections.
6. The most difficult part of making an operation, it provides greater amount of
satisfaction because it is carried out with more care and skill.
7. The board used for project has copper-foil thickness in range of 25 40 75
microns.
8. The soldering quality requires 99.99% efficiency.
9. It is necessary to design copper path extra large. There are two main reasons
for this.
10. The copper may be required to carry an extra large overall current.
11. It acts like a kind of a screen or ground plane to minimize the effect of
interaction.
12. The first function is to connect the components together in there right
sequence with minimum need for interlinking i.e. the jumpers with wire
connections.
13. It must be noted, that when layout is done, on the next day it should be
dripped in the solution and board is moved continuously right and left after
etching perfectly the board is cleaned with water and is drilled.
14. After that holes are drilled with 1mm or 0.8mm drilled.
15. The printed circuit board is now ready for mounting the components on it.
5.5 PCB Etching
STEP-1:- After cutting the copper clad sheet to size, the PCB is cleaned with thinner, so
that the dust on the PCB is removed and we get a shiny surface. Then we insert the PCB in
Dip coat, that is, negative photo resistive material.
Figure 5.2 PCB being scrubbed clean
Figure 5.3 PCB coated in negative photoresist
STEP-2:- The photo resistive material should be made hard on the PCB for which the PCB
is kept in the oven for four minutes.
Figure 5.4 PCB Oven
STEP-3:- After the liquid is made hard, it is kept in the UV exposure for two minutes. In
the UV exposure, the circuit is kept with its layout. The ultraviolet rays are passed through
the PCB.
Figure 5.5: UV Exposer
STEP-4:- Thm we have to expose out PCB to nail polish remover solution which is also
called as developer liquid. As a result of this an impression of tracks is formed on the PCB.
Repeat the STEP-2, in which the PCB is kept in the oven for four minutes.
Figure 5.6: Agitating PCB
STEP-5:- After removing the PCB from the oven, the tracks on the PCB will be developed.
After this the PCB is dipped into the PRITO-ETCH for five minutes. The solution used in
the PEORO-ETCH is feriic chloride. Due to this tracks are fully developed on the PCB.
Figure 5.7: Easy Etcher
STEP-6:- The PCB is then washed in water and cleaned with the help of a cloth.
5.6 PCB Drilling
Description: holes through a PCB are typically drilled with tiny drill bits made of solid
tungsten carbide. The drilling is performed by the automated drilling machines with
placement controlled drill (NCD) files or “Excellon”. The drill file describes the location
and size of each drilled hole. These holes are often filled with annular rings (hollow rivets)
to create via. Allow the electrical and thermal connection of conductors on opposite sides of
PCB.
Most common laminate is epoxy filled fiberglass. Drill bit wear is in part due to the fact
that glass, being harder than steel on the Mohs scale, can scratch steel. High drill speed
necessary for cost effective drilling of hundreds of holes per board causes very high
temperatures at the laminate fiber. Copper is softer than epoxy and interior conductors
may suffer damage during drilling.
When very small via are required, drilling the mechanical bits is costly because of high
rates of wear and breakage. In this case, the via may be evaporated by lasers. Laser-drilled
via typically have an inferior surface finish inside the holes. These holes are called micro
via.
It is also possible with controlled-depth drilling, laser drilling, or by pre-drilling the
individual sheets of the PCB before the lamination, to produce holes that connect only some
of the copper layers, rather than passing through the entire board. These holes are called
blind via when they connect an internal copper layer to an outer layer, or buried via when
they connect two or more internal copper layers and no outer layers.
The walls of the holes, for boards with or more layers, are made conductive then plated
with the copper to form plated-through holes that electrically connect the conducting layers
of the PCB. For multilayer boards those with layers or more, drilling typically produces a
smear of the high temperature decomposition products of binding agent in the laminate desmear process, or by plasma-etch. Removing (etching back) the smear also reveals the
interior conductors as well.
5.7 Drilling Process
1. First the PCB is placed on the drilling machine and drill bit is inserted. We used the drill
bit of 0.8mm.
2. The PCB is placed in such a way that the drill bit is exactly on the top of the place where
we need to drill.
3. Then, the machine is turned on and the handle is to pressed down to drill on the PCB.
4. Care should be taken while drilling that PCB is firmly held or else it will come up into
the drill bit.
5. After drilling first hole we checked whether the component is getting inserted in the hole
or not. Some components like diodes and TSOP had thick leads which were not able to get
into the hole.
6. For this we changed the drill bit to 1mm and drilled those holes again so that
components were properly inserted.
5.8 Soldering
Steps:
•
For soldering of nay joints first the terminal to be soldered are cleaned to remove
oxide film or dirt on it. If required flux is applied on the points to be soldered.
•
Now the joint to be soldered is heated with the help of soldering iron. Heat applied
should be such that when soldered is touched to joint, it must melt quickly.
•
The joint and the soldering iron are held such that the molten solder should flow
smoothly over the joint.
•
When joint is completely covered with molten solder the soldering iron is removed.
•
The bright shining solder indicates good soldering.
•
In case if dry solder join, and air gap remains in between the solder material and
joint. It means that soldering is improper. This is removed and again soldering is
done.
•
In case of dry solder join, and air gap remains in between the solder material and
joint. It means that soldering is improper. This is removed and again soldering is
done.
•
In this way all the components are soldered on PCB.
5.9 Cold Solder Joints
1. A “cold solder joint” can occur when not enough heat is applied to the component,
board, or both. Another common cause is a component moving before the solder has
completely cooled and solidified. A cold joint is brittle and prone to physical failure. It is
also generally a very high resistance connection which can effect the operation of the circuit
or cause it to fail completely.
2. Cold joints can often be recognized by a characteristic grainy, dull gray color, but this is
not always the case. A cold joint can often appear as a ball of solder sitting on the pad and
joint may even move. Below is the shocking image of every example of a bad solder joint
you will ever see. It appears that this FM transmitter kit was assembled using the technique
of apply solder to iron then drip onto joint”. If your joints are looking like this, then stop
and practice after rereading this page. Note that not a single of these joints is acceptable,
but amazingly, the circuit worked.
3. Most cold solder joints can be easily fixed. Generally all that is required to reheat the
joint and apply a little more solder. If there is already too much solder on the joint, then
the joint will have to be de-soldered and then soldered again. This is done by first removing
the old solder with a de-soldering tool or simply by heating it up and flicking it off with the
iron. Once the old solder is off, you can re-solder the joint, making sure to heat it
thoroughly and keep it still as it cools.
5.10 Top View of Board
5.11 LED Flasher
5.12 IR transmitter
5.13 IR reciever
5.14 PCB Layout
CHAPTER 6
ALGORITHM, FLOWCHART & PROGRAMMING
6.1 ALGORITHM
1. Switch on the power supply.
2. Check if the phone is switched on and if it is running the required app.
3. Check if there is an intrusion.
4. Send a positive voltage to LED flasher if there is intrusion
6.2 Flow chart
Transmit IR to reciver
IF no
Is there
any
intrusion?
If yes
Positive voltage goes
from the receiver to
CHAPTER 7
the LED flasher and
the LED begins
TROUBLESHOOTING
AND TESTING
flashing.
7.1 Troubleshooting
Description:
Troubleshooting is a form of solving , often applied to repair failed circuits. It is a logical,
schematic search for a source of a problem so that it can be solved, and circuit can be made
operational again. Troubleshooting is needed to develop and maintain complex systems
where the symptoms of a trouble can have many possible causes. Troubleshooting requires
identification of the malfunction(s) or symptoms within the system and confirms the
solution so that it can work again.
7.1.1 Need of Troubleshooting
1. Every product, circuit and instruments are designed to give desired output, but there are
many problems associated with the design which tend to produce unexpected output.
Therefore, for satisfactory performance, it needs to be troubleshooted so that the circuit
can be made operational again.
2. Troubleshooting is needed to develop and maintain complex systems where the
symptoms of problem can have many possible causes.
3. It is needed for identifying the symptoms and rectifying the problems so that it gives the
desired output.
4. Troubleshooting is used in many fields such as engineering, systems administration,
electronics, automotive repair and diagnostic medicine.
7.1.2 Steps prior to troubleshooting
1. Before applying power, read the instruction carefully to check we haven’t missed
anything, and whether there are any specific instruction for switching on and testing.
2. Check again that we have all polarity sensitive components the right way around , and
that all components are in the correct places. Then check whether off board components
are connected correctly.
3. Check the underside of board for short circuit between tracks which is common reason
for circuit failing to work.
4. When we are sure that everything is correct, apply power and see if the circuit behaves
as expected.
7.1.3 Troubleshooting steps
1. Identify the system:
Determine what the voltage level in circuit should be so that you know what to look for.
2. Power Check : The first thing to do while checking a defective circuit is to make sure the
power cord is plugged in and the fuse is not burnt. In case of battery powered system, make
sure the battery is good.
3. Perform sensory check: After power check, observe for the obvious defects. Example,
poor solder connection, broken tracks, broken component and burnt out fuses. Also when
certain type of component fail, may be able to detect a smell of smoke. Since some failures
are detected by their temperature, unplug the circuit and immediately use your sense of
touch to detect and overheated component. Always perform sensory check before
proceeding with more sophisticated troubleshooting methods. Never touch operating
circuit because there may be risk of burn or electric shock.
4. Signal tracing : In this we look for a point in the circuit or a system where we first lose
signal or an incorrect signal first occurs. There are 3 ways of signal tracing as given below
:
a. Method 1: It starts at the input of a circuit where there is the known input signal work
towards the output. Check the signal at successive test point until you get incorrect
measurement, when it is found, the problem is isolated from the last test point to the
present test points.
b. Method 2: It starts at the output of the circuit and work towards the input. Check for
the voltage at each test point until you get correct measurement. At this point you have
isolated problem between the last point & the current test point.
c. Method 3: This method is called half splitting. It starts at the middle of the test circuit . If
a beginning of test point has a correct signal you know that circuit is working properly
from input to that test point. This means that the fault is some ware between test point and
the output. Therefore begin signal tracing from test points towards output and get the
point at the fault.
5. Fault analysis:
a. Voltage analysis: Afterperforming the visible testing if the problem still persists, then
go for voltage analysis. In this method the voltage at different test points is checked.
b. resistance analysis: In this analysis, power supply connected to the circuit must be
switched when resistance is measured. Resistance analysis is generally used for continuity
testing. Eg, check the continuity of PCB track from one test point to other or in case of
double sided PCB it helps in checking the connectivity between the holes from both the
sides. Similarly this can be used for testing the components such as diode, capacitor and
transistor (e.g. open & short). This method requires the instrument such as DMM.
c. Signal Analysis: Sometimes its important to observe the nature of the signal at the test
point (e.gincase of rectifier). Whereas it is not possible in voltage analysis. By observing the
waveform at the test point we can estimate the waveform distortion. For testing the circuit
such as rectifier, multi vibrator, amplifier it is important to know the nature. Therefore
signal analysis is done. For carrying signal analysis we require CRO.
6. Replace or repair :
With the power turned off, replace the defective components or repair defective
connections. Turn on the power, check the proper operation of the circuit.
7.2 TROULESHOOTING OF OUR PROBLEMS
Testing refers to the initial phase of testing where the module is not yet connected to the
wireless medium. This is the part of the testing process wherein we check if the MODEM
receives the AT command from the microcontroller and makes its response in form of a
new message, an ERROR message, or an OK message (all in form of bit strings). The
oscilloscope probes are connected to P3.0 & P3.1 which are internally connected to the Tx&
Rx lines of the microcontroller. In this at first we use transformer of 230V 500 mA but as
we tested there was lot of voltage at the input of the circuit so there was loading effect &
transformer was giving only 7V to the circuit instead of 12V and the bulb was not glowing
as it was connected to the relay. So we troubleshooted the problem using the DMM and
changed the transformer to 12V, 1A and thus we got proper voltage at the input of the
circuit.
CHAPTER 8
MERITS, DEMERITS, APPLICATION AND FUTURE IMPROVEMENTS
8.1 Merits
1. SIMPLE & EASY OPERATION
2. LESS EXPENSIVE
The total cost of our project is quite less & is easy to initialise&setup even for a common
man.
4. POWER EFFICIENT
The power requirements of our project are quite less. The maximum power required by
the circuit is 12 volts.
5. SMALL SIZE
All the circuits are small enough to fit in the palm of an average human.
6. LIVE STREAMING POSSIBLE
Live streaming of all the events occurring in the chosen area of application is possible.
8.2 Demerits
As there are advantages, there are some limitations of this project.
1. HACKABLE
Since the project features an android device it carries a potential to be hacked.
2. FALSE TRIGGER
There stands a probability of the system to be falsely triggered. This may occur due to
larger than average dust particles, pets, pests like rodents.
3. OWNER MONITORING DEVICES MUST BE SWITCHED ON
For live streaming to be possible the owner must have a device(smartphone/pc) switched
on.
8.3APPLICATION
1. Offices
2. Safes
3. Homes
4. Garages
5. Exhibits at museums etc.
8.4 Future Improvements
With increased knowledge and budget the mobile phone can be replaced by a camera. It
can be a point and shoot variant or even a DSLR. As new sensors enter the market they can
be integrated into our project.
CONCLUSION
In India almost 98% of homes don’t have any security system apart from the traditional
locks which can be picked very easily. Our project aims to provide a cheap and effective
solution to this problem. The versatility of the project means that it can be applied in
multiple ways. Safes, garages, homes, exhibits etc can be easily secured using our project.
Videos can be streamed directly to the owner or any concerned figure with authority over
the object/location under protection. In a situation that the security system fails to contain
the thief/thieves the video can be used for facial recognition and later in the trial. The only
Pre- requisite for this is that the person receiving the stream has to have his smartphone/pc
switched on.
Thus we can conclude that this project provides a economically suitable solution to the
security problems of people with little disadvantages.
BIBLIOGRAPHY
Website:
1) http://en.wikipedia.org/wiki/Wikipedia
2) www.instructables.com
3) www.555timercircuits.com
Books:
1) Electronics For you - Magazine
2)Op-Amps and Linear Integrated Circuit by RamakantGayakwad.