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POWER MANAGEMENT FOR SHOPPING MALLS WITH BIDIRECTIONAL VISITOR COUNTING
A Mini Project report submitted
In partial fulfillment of the requirements
For the award of degree of
BACHELOR OF TECHNOLOGY
In
ELECTRONICS AND COMMUNICATION ENGINEERING
By
B.PRAGZNA M.NARESHKUMAR
A.VIJAY SIVAJI G.NIRANJAN KISHORE
Under the esteemed guidance of
Prof. R.VENKATARAO M.Tech
Department of ECE
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
SRI VAISHNAVI COLLEGE OF ENGINEERING
SINGUPURAM, SRIKAKULAM, ANDHRA PRADESH
2011
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
SRI VAISHNAVI COLLEGE OF ENGINEERING
SINGUPURAM
CERTIFICATE
This is certify that the mini project work entitled “ POWER MANAGEMENT
FOR SHOPPING MALLS WITH BIDIRECTIONAL VISITOR COUNTING ”, is a
bonafide work done by PRAGZNA.B , NARESH KUMAR .M , VIJAY SIVAJI .A , and
NIRANJAN KISHORE .G submitted in partial fulfillment of the requirements for the award of
the degree of BACHELOR OF TECHNOLOGY in ELECTRONICS AND
COMMUNICATION ENGINNERING .
HEAD OF DEPARTMENT UNDER GUIDENCE
BHASKAR MURTHI, R.VENKATARAO M.Tech
Head of Department, E.C.E Department of E.C.E
ACKNOWLEDGEMENT
This report would be incomplete without the mention of those who have directly or
indirectly helped us during the tenure of this project.
We would like to thank Sri L.S.SASTHRY GARU, Principal, and SRI VAISHNAVI
COLLEGE OF ENGINEERING for having permitted us to take up this project.
We would also like to express our deepest sense of gratitude towards
Sri.M.V.H.BHASKARAMURTHY , Head of the Department , Electronics and
communication Engineering , Sri Vaishnavi College of Engineering and Sri
T.MANIKYALARAO GARU, the Project co-ordinator , E.C.E Department, Sri Vaishnavi
College of Engineering for their invaluable help during this project. Their guidance has been
instrumental and has proved to be of immense help at every stage of the project.
We would like to thank our internal guide Sri R.VENKATARAO GARU, Assistant
Professor, Electronics and communication Engineering , Sri Vaishnavi College of Engineering
for constantly monitoring our progress and suggesting improvements at various stages in the
project
We would like to thank all the other staff members of Electronics and communication
Engineering Department, Sri Vaishnavi College of Engineering, for cooperating with us all
through the period of project.
We would like to express our heartfelt gratitude towards Sri MOHAMMED IRFAN of
PRECISION INFOMATICS PRIVATE LTD. for his continuous support throughout the tenure
of the project. We are grateful to him for spending some of his precious time in helping us out in
solving the problems during the project.
Lastly, we would like to thank everyone who has been involved in the progress of the
project, whose contributions, have added a lot of value.
PRAGZNA BALIVADA
NARESHKUMAR MOYYI
VIJAY AGURU
NIRANJAN KISHORE GUDLA
ABSTRACT
Now-a-days with the increase of electronic appliances the power consumption increases.
We can conserve power in home with our personal interest. But it is different in case of public
malls and halls. Hence we need to seek the assistance of some external setup viz. visitors’
counter.
The Bidirectional visitor counter is designed for shopping malls to reduce the power
usage according to the count of persons in the hall. A unique architecture of occupancy sensors
includes entry/exit sensors for detecting movement through doorways. The bidirectional sensors
are used to sense the entry and exit. This project is designed around a microcontroller which
forms the control unit of the project. The central embedded controller controls the devices
according to the number of persons entered into the shopping mall in response to the entry/exit
sensors.
The counter section consists of two IR LEDs, two photodiode detectors. The movement of
objects including the direction of their movement is detected by the arrangement of the IR LED
and photodiode detector pairs. The photodiode of each pair is mounted opposite to its
corresponding IR LED fall directly on the photodiode detector.
The Software for Visitor counter is written in “Embedded C” language and compiled
using AVR STUDIO .This Software allows for historic data analysis, data aggregation and time
plotting performing precise calculations such as the average time an individual spends inside a
particular zone. The hardware includes Atmel series (ATMEGA8 ) micro controller and
LCD(Seven segment Display).Night -clubs, museums, entertainment venues and other places
where many people gather, are often subject to maximum occupancy regulations.
LIST OF FIGURES
Figure number Name Page number
1 Block Diagram
2 Basic Layout of Microcontroller
3 A simple 5V DC Regulated Power Supply System
4 Step-down Transformer
5 Block Diagram of Microcontroller-ATMEGA8
6 Architecture of ATMEGA8
7 Pin Diagram of ATMEGA8
8 Electromagnetic Spectrum
9 A radio frequency energy wave superimposed -
upon an infrared energy wave
10 Liquid Crystal Display
11 Pin diagram of 2x16 LCD Display
12 Transmitter &Receiver Setup
13 Schematic Diagram of ATMEGA8
CONTENTS
Pg.No
1. EMBEDDED SYSTEM
1.1 Introduction to Embedded Systems
1.2 Examples of Embedded Systems
1.3 Microcontrollers and Microprocessors
1.4 Typical Microcontroller Architecture and Features
1.5 The UART: What it is and how it works
1.5.1 Synchronous Serial Transmission
1.5.2 Asynchronous Serial Transmission
2. REGULATED POWER SUPPLY
2.1 What is a power supply?
2.2 Recommended specifications
2.3 Power Requirements
2.4 Power Source
2.5 Regulators
2.6 TRANSFORMER
3. MICRO CONTROLLER
3.1 Features
3.2 Micro Controller
3.3 A.V.R Description
Pg.No
3.4 Architecture
3.5 PinDiagram
3.5 Pin Description
4. INFRARED RANGE SENSORS
4.1 Introduction
4.2 Wireless Communication
4.3 Infrared Technology
4.4 IR Advantages
4.5 IR Disadvantages
4.6 Health Risks
4.7 Security
4.8 Importance of Standards
5. LIQUID CRYSTAL DISPLAY
5.1 Introduction
5.2 Interfacing LCD to the Microcontroller
5.3 Features
5.4 DIAGRAM
5.5 PIN DIAGRAM
6. VISITOR’S COUNTER
6.1 Introduction
6.2 How the People Counter Works?
6.3 Unparalleled Accuracy >99%
6.4 Easy Installation and Integration
6.5 Advantages
6.6 Schematic Diagram
INTRODUCTION
Mall management has been identified as a critical factor for the success of malls and the
retail industry across the world. One of the key management parameters is the POWER
MANAGEMENT. Power management in shopping malls is not a small issue as it they are the
most crowded places. We need to conserve power in malls using some sophisticated instruments
like BIDIRECTIONAL VISITORS’ COUNTER.
Developing an accurate understanding of the precise number of people currently present
in a building or moving through high-traffic areas is an invaluable asset for safety and security
professionals, as well as for marketing intelligence initiatives, and staff and energy optimization.
The Visitors’ Counter delivers real-time data which allows for the following applications:
Occupancy monitoring to:
control maximum or minimum occupancy.
support evacuation measures.
trigger demand-controlled ventilation (DCV).
Wrong-way detection and bi-directional counting.
Wait time determination and queue management.
Occupancy monitoring and analysis solution:
Performs bi-directional count at each entrance and exit
Offers >99% accuracy.
Runs on embedded software.
Based on IR Sensor™ technology.
The following is the block diagram of POWER MANAGEMENT WITH
BIDIRECTIONAL VISITORS’ COUNTER.
Each block in the diagram are explained in the following briefly.
BLOCK DIAGRAM:
Micro
Controller
Regulated Power supply
Devices
Liquid crystal display
Hall with IR sensors
CHAPTER-1
EMBEDDED SYSTEMS
1.1 Introduction to Embedded Systems
An embedded system is a special-purpose computer system designed to perform a
dedicated function. Unlike a general-purpose computer, such as a personal computer, an
embedded system performs one or a few pre-defined tasks, usually with very specific
requirements, and often includes task-specific hardware and mechanical parts not
usually found in a general-purpose computer. Since the system is dedicated to specific
tasks, design engineers can optimize it, reducing the size and cost of the product.
Embedded systems are often mass-produced, benefiting from economies of scale.
Physically, embedded systems range from portable devices such as digital watches
and MP3 players, to large stationary installations like traffic lights, factory controllers,
or the systems controlling nuclear power plants. In terms of complexity, embedded
systems run from simple, with a single microcontroller chip, to very complex with
multiple units, peripherals and networks mounted inside a large chassis or enclosure.
1.2 Examples of Embedded Systems
An embedded system typically has a specialized function with programs stored on
ROM. Examples of embedded systems are chips that monitor automobile functions,
including engine controls, antilock brakes, air bags, active suspension systems,
environmental systems, security systems, and entertainment systems. Everything
needed for those functions is custom designed into specific chips. No external operating
system is required.
Network managers will need to manage more and more embedded systems devices,
ranging from printers to scanners, to handheld computing devices, to cell phones. All of
these have a need to connect with other devices, either directly or through a wireless or
direct-connect network.
1.3 Microcontrollers and Microprocessors
A microcontroller (or MCU) is a computer-on-a-chip. It is a type of microprocessor
emphasizing self-sufficiency and cost-effectiveness, in contrast to a general-purpose
microprocessor (the kind used in a PC).
A microprocessor is a programmable digital electronic component that
incorporates the functions of a central processing unit (CPU) on a single semi
conducting integrated circuit (IC). The microprocessor was born by reducing the word
size of the CPU from 32 bits to 4 bits, so that the transistors of its logic circuits would
fit onto a single part. One or more microprocessors typically serve as the CPU in a
computer system or embedded system
1.4 Typical Microcontroller Architecture and Features:
The basic internal designs of microcontrollers are pretty similar. Figure1 shows the block
diagram of a typical microcontroller. All components are connected via an internal bus and are
all integrated on one chip. The modules are connected to the outside world via I/O pins. The
following list contains the modules typically found in a microcontroller
Figure 2: Basic Layout of Microcontroller
Processor Core: The CPU of the controller. It contains the arithmetic logic unit, the
control unit, and the registers (stack pointer, program counter, accumulator register,
register file . . .).
Memory: The memory is sometimes split into program memory and data memory. In
larger controllers, a DMA controller handles data transfers between peripheral
components and the memory.
Interrupt Controller: Interrupts are useful for interrupting the normal program flow in
case of (important) external or internal events. In conjunction with sleep modes, they help
to conserve power.
Timer/Counter: Most controllers have at least one and more likely 2-3 Timer/Counters,
which can be used to timestamp events, measure intervals, or count events. Many
controllers also contain PWM (pulse width modulation) outputs, which can be used to
drive motors or for safe breaking (antilock brake system, ABS). Furthermore the PWM
output can, in conjunction with an external filter, be used to realize a cheap digital/analog
converter.
Digital I/O: Parallel digital I/O ports are one of the main features of microcontrollers.
The number of I/O pins varies from 3-4 to over 90, depending on the controller family
and the controller type.
Analog I/O: Apart from a few small controllers, most microcontrollers have integrated
analog/digital converters, which differ in the number of channels (2-16) and their
resolution (8-12 bits). The analog module also generally features an analog comparator.
In some cases, the microcontroller includes digital/analog converters.
1.5 The UART: What it is and how it works
The Universal Asynchronous Receiver/Transmitter (UART) controller is the key
component of the serial communications subsystem of a computer. The UART takes bytes of
data and transmits the individual bits in a sequential fashion. At the destination, a second UART
re-assembles the bits into complete bytes.
Serial transmission is commonly used with modems and for non-networked
communication between computers, terminals and other devices. There are two primary forms of
serial transmission: Synchronous and Asynchronous.
1.5.1 Synchronous Serial Transmission
Synchronous serial transmission requires that the sender and receiver share a clock with
one another, or that the sender provide a strobe or other timing signal so that the receiver knows
when to “read” the next bit of the data. In most forms of serial Synchronous communication, if
there is no data available at a given instant to transmit, a fill character must be sent instead so
that data is always being transmitted. Synchronous communication is usually more efficient
because only data bits are transmitted between sender and receiver, and synchronous
communication can be more costly if extra wiring and circuits are required to share a clock
signal between the sender and receiver.
1.5.2 Asynchronous Serial Transmission
Asynchronous transmission allows data to be transmitted without the sender having to
send a clock signal to the receiver. Instead, the sender and receiver must agree on timing
parameters in advance and special bits are added to each word which is used to synchronize the
sending and receiving units.
When a word is given to the UART for Asynchronous transmissions, a bit called the
"Start Bit" is added to the beginning of each word that is to be transmitted. The Start Bit is used
to alert the receiver that a word of data is about to be sent, and to force the clock in the receiver
into synchronization with the clock in the transmitter. These two clocks must be accurate enough
to not have the frequency drift by more than 10% during the transmission of the remaining bits in
the word. After the Start Bit, the individual bits of the word of data are sent, with the Least
Significant Bit (LSB) being sent first. Each bit in the transmission is transmitted for exactly the
same amount of time as all of the other bits, and the receiver “looks” at the wire at approximately
halfway through the period assigned to each bit to determine if the bit is a 1 or a 0.The sender
does not know when the receiver has “looked” at the value of the bit. The sender only knows
when the clock says to begin transmitting the next bit of the word. When the entire data word has
been sent, the transmitter may add a Parity Bit that the transmitter generates. The Parity Bit may
be used by the receiver to perform simple error checking. Then at least one Stop Bit is sent by
the transmitter.
CHAPTER - 2
REGULATED POWER SUPPLY
Small general purpose micros like PICs and Atmel Chips, mostly operating from 5V and
requiring 10 to 50 mA. Some may operate from lower voltages such as 3.3V or 2.5V. The
principles are mostly the same.
2.1 What is a power supply?
It’s a simple source of reliable low voltage power for the micro and associated circuitry.
The goal is to provide a stable, low voltage supply to the micro. The operation of the micro must
not be affected by the power supply. The power supply itself must be reliable and stable. The
power supply should not cause problems during development.
Figure3: A simple 5V DC Regulated Power Supply System
2.2 Recommended specifications
For a small micro project, for development and experimenting, use a 12V DC 500mA plug-pack
supplying a 3-terminal voltage regulator such as a 78L05 or 7805.
The regulator should not be too much larger than you actually need. So, for a 50mA load
use a 78L05 which is rated at 100mA but will deliver a bit more. Put a series diode in the
positive line before the input capacitor. This protects it when the plug-pack is connected the
wrong way round (it happens). The input capacitor should be close to the regulator and at least
100uF at 25V. On the output side of the regulator you should have a 10uF capacitor.If the
regulator gets too hot to hold comfortably for a few seconds securely between thumb and finger
you need a larger regulator or add a heat sink. The capacitors must be close to the regulator so
don't run long skinny wires from the board to the regulator to get to the heat sink. It is required to
dot a few 0.1uF decoupling capacitors around the circuit.
2.3 Power Requirements
The micro will require 5 volts DC probably no more than 5 to 50 mA. The associated
circuitry may require more current but can generally be run from the same +ve 5V supply rail as
the micro. Remember that small micros are mostly CMOS devices and although the average
current requirement is maybe a few milliamps, the power supply must be able to deliver peaks of
many 10s or even 100s of milliamps for continued reliable operation.
2.4 Power Source
The power will typically come from a mains power supply or batteries. The power supply
as a whole can be divided into two sections; the power source and the local regulator. If the local
regulator is properly designed and constructed, the power source is not that critical. The power
source can be as simple as a AC or DC plug-pack or a transformer-rectifier-capacitor or a
battery. So; for a 5V regulator it should be fed with a measured 10V DC or more. A typical 12V
DC unregulated plug-pack will put out 15 to 18 volts with no load connected.
2.5 Regulators
The common 7800 series voltage regulators are reasonably priced and produce simple
and reliable power supplies if used correctly. The 78L05 and 7805 are good regulators for simple
micro projects. If variable or different voltage is required, the LM317 is available. These are all
linear regulators. They require input and output capacitors located close to the regulator in order
to operate reliably. Without these capacitors or if they are too small or too far away, the regulator
can oscillate at high frequencies depending on the load etc. A series diode on the input +ve side
can be included. This prevents reverse polarity of the incoming supply damaging the regulator or
other circuitry. Usually a common 1N4007 is used.
2.6 TRANSFORMER:
The transformer is a device that transfers electrical energy from one electrical circuit to
another electrical circuit through the medium of magnetic field and without a change in the
frequency .The electric circuit which receives energy from the supply mains is called primary
winding and the other circuit which delivers electric energy to the load is called the secondary
winding.
This is a very useful device, indeed. With it, we can easily multiply or divide voltage and
current in AC circuits,. Indeed, the transformer has made long-distance transmission of electric
power a practical reality, as AC voltage can be “stepped up” and current “stepped down” for
reduced wire resistance power losses along power lines connecting generating stations with
loads.
Figure 4 Step down transformer
CHAPTER – 3
MICRO CONTROLLER
3.1 Micro Controller :
Microprocessors and microcomtrollers step from basic idea .the contrast between a micro
controller and a microprocessor is best exemplified bt the fact that most microprocessors have
many operational codes (opcodes) for moving data from external memory to the CPU ;
microcontrollers will have many.The microrocessor is concerned with rapid movment of code
and data from external addresses to the chip;the microcontroller is concerned with the rapid
movment if bits within the chip;The microcontroller can function as a computer with the addition
of no external digital parts;the picroprocessor must have additional parts to be operational
3.2 Features:
High-performance, Low-power AVR® 8-bit Microcontroller.
Advanced RISC Architecture
130 Powerful Instructions – Most Single-clock Cycle Execution – 32 x 8 General
Purpose Working Registers
Fully Static Operation
Up to 16 MIPS Throughput at 16 MHz – On-chip 2-cycle
Multiplier.
High Endurance Non-volatile Memory segments.
8K Bytes of In-System Self-programmable Flash program memory –
512 Bytes EEPROM ,1K Byte Internal SRAM
Write/Erase Cycles: 10,000 Flash/100,000 EEPROM –
Data retention: 20 years at 85°C/100 years at 25°C (1 )
Optional Boot Code Section with Independent Lock Bits In-
System Programming by On-chip Boot Program.
True Read-While-Write Operation.
Programming Lock for Software Security.
Peripheral Features.
One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture
Mode
Real Time Counter with Separate Oscillator – Three PWM Channels
8-channel ADC in TQFP and QFN/MLF package
6-channel ADC in PDIP package Six
Channels10-bit Accuracy Byte-oriented Two-
wire Serial Interface – Programmable Serial
USART
Programmable Watchdog Timer with Separate On-chip Oscillator –
On-chip Analog Comparator
Special Microcontroller Features
Power-on Reset and Programmable Brown-out Detection
– Internal Calibrated RC Oscillator
External and Internal Interrupt Sources
Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down,
and Standby
I/O and Packages
23 Programmable I/O Lines
28-lead PDIP, 32-lead TQFP, and 32-pad QFN/MLF
Operating Voltages
2.7 - 5.5V (ATmega8L) –
4.5 5.5V (ATmega8)
Power Consumption at 4 MHz, 3V, 25C
Active: 3.6 mA
Idle Mode: 1.0 mA
Power-down Mode: 0.5 µA
3.3 A.V.R Description:
The AVR core combines a rich instruction set with 32 general purpose working registers.
All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two
independent registers to be accessed in one single instruction executed in one clock cycle. The
resulting architecture is more code efficient while achieving throughputs up to ten times faster
than conventional CISC microcontrollers.
The device is manufactured using Atmel’s high density non-volatile memory technology.
The Flash Program memory can be reprogrammed In-System through an SPI serial interface, by
a conventional non-volatile memory programmer, or by an On-chip boot program running on the
AVR core. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a
monolithic chip, the Atmel ATmega8 is a powerful microcontroller that provides a highly-
flexible and cost-effective solution to many embedded control applications.
The ATmega8 AVR is supported with a full suite of program and system development
tools, including C compilers, macro assemblers, program debugger/simulators, In-Circuit
Emulators, and evaluation kits.
BLOCK DIAGRAM:
Figure5: Block Diagram of Microcontroller-ATMEGA8
3.4 Architecture:
Figure6 : Architecture of ATMEGA8
3.5 PinDiagram:
Figure7: Pin Diagram of ATMEGA8
3.6 Pin Description
VCC Digital supply voltage.
GND Ground.AREF AREF is the analog reference pin for the A/D Converter
ADC7.6 In the TQFP and QFN/MLF package, ADC7..6 serve as analog inputs to the A/D converter These pins are powered from the analog supply and serve as 10-bit ADC channel
AVCC
AVCC is the supply voltage pin for the A/D Converter, Port C (3.0), and
ADC (7.6). It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter. Note that Port C (5.4) use digital supply voltage, VCC.
RESETIt is input. A low level on this pin for longer than minimum pulse generates input.
Port B (PB7..PB0)
XTAL1/XTAL2/TOSC1/TOS2
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors
(selected for each bit). Port B output buffers have symmetrical drive
characteristics with both high sink and source capability. As inputs,
Port B pins that are externally pulled low will source current if the pull-
up resistors are activated. The Port B pins are tri-stated when a reset
condition becomes active, even if the clock is not running .Depending
on the clock selection fuse settings, PB6 can be used as input to the
inverting.
Port C (PC5..PC0)
PC6/RESET
Port C is an 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port C output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin
Port D (PD7..PD0) Port C output buffers have symmetrical drive characteristics with both high sink and source
CHAPTER – 4
IR SENSORS
4.1 Introduction:
As next-generation electronic information systems evolve, it is critical that all people
have access to the information available via these systems. Examples of developing and future
information systems include interactive television, touch screen-based information kiosks, and
advanced Internet programs. Infrared technology, increasingly present in mainstream
applications, holds great potential for enabling people with a variety of disabilities to access a
growing list of information resources. Already commonly used in remote control of TVs, VCRs
and CD players, infrared technology is also being used and developed for remote control of
environmental control systems, personal computers, and talking signs.
For individuals using augmentative and alternative communication (AAC) devices, infrared or
other wireless technology can provide an alternate, more portable, more independent means of accessing
computers and other electronic information systems.
4.2 Wireless Communication:
Wireless communication, as the term implies, allows information to be exchanged
between two devices without the use of wire or cable. Information is being transmitted and
received using electromagnetic energy, also referred to as electromagnetic radiation. One of the
most familiar sources of electromagnetic radiation is the sun; other common sources include TV
and radio signals, light bulbs and microwaves.
The electromagnetic spectrum classifies electromagnetic energy according to frequency
or wavelength (both described below). As shown in Figure 1, the electromagnetic spectrum
ranges from energy waves having extremely low frequency (ELF) to energy waves having much
higher frequency, such as x-rays.
Figure 8 Electromagnetic Spectrum
In Figure 8 ,A horizontal bar represents a range of frequencies from 10 Hertz (cycles per
second) to 10 to the 18th power Hertz. Some familiar allocated frequency bands are labeled on
the spectrum. Approximate locations are as follows. (Exponential powers of 10 are abbreviated
as 10exp.)
10 Hertz: extremely low frequency or ELF.
10exp5 Hertz: AM radio.
10exp8 Hertz: FM radio.
10exp16 Hertz: Infrared (frequency range is below the visible light spectrum).
10exp16 Hertz: Visible Light.
10exp16 Hertz: Ultraviolet (frequency range is above the visible light spectrum).
10exp18 Hertz: X-rays.]
4.3 Infrared Technology:
Infrared radiation is the region of the electromagnetic spectrum between microwaves and visible
light. In infrared communication, an LED transmits the infrared signal as bursts of non-visible
light. At the receiving end a photodiode or photoreceptor detects and captures the light pulses,
which are then processed to retrieve the information they contain.
Figure 9 depicts an infrared energy wave and a radio energy wave, and illustrates the two
different energy wavelengths. As is expected based on the electromagnetic spectrum, the infrared
wave is higher frequency and therefore shorter wavelength than the radio wave. Conversely, the
radio wave is lower frequency and therefore longer wavelength than the infrared wave.
Figure 9 A radio frequency energy wave superimposed upon an infrared energy wave
The above illustrates the inverse relationship between frequency and wavelength. The
infrared energy wave completes nearly 5 and a half cycles in the time that the radio frequency
wave completes 2 cycles. ]
Infrared technology is highlighted because of its increasing presence in mainstream
applications, its current and potential usage in disability-related applications, and its advantages
over other forms of wireless communication.
Some common applications of infrared technology are listed below.
1. Augmentative communication devices
2. Car locking systems
3. Computers, Headphones
4. Emergency response systems
5. Environmental control systems
6. Home security systems
4.4 IR Advantages:
1. Low power requirements: therefore ideal for laptops, telephones, personal digital
assistants.
2. Low circuitry costs: $2-$5 for the entire coding/decoding circuitry .
3. Simple circuitry: no special or proprietary hardware is required, can be incorporated into
the integrated circuit of a product
4. Higher security: directionality of the beam helps ensure that data isn't leaked or spilled to
nearby devices as it's transmitted
5. Few international regulatory constraints: IrDA (Infrared Data Association) functional
devices will ideally be usable by international travelers, no matter where they may be
6. High noise immunity: not as likely to have interference from signals from other devices
4.5 IR Disadvantages:
1. Line of sight: transmitters and receivers must be almost directly aligned (i.e. able to see
each other) to communicate
2. Blocked by common materials: people, walls, plants, etc. can block transmission
3. Short range: performance drops off with longer distances
4. Light, weather sensitive: direct sunlight, rain, fog, dust, pollution can affect transmission
5. Speed: data rate transmission is lower than typical wired transmission
4.6 Health Risks:
Any time electric current travels through a wire, the air, or runs an appliance, it produces
an electromagnetic field. It is important to remember that electromagnetic fields are found
everywhere that electricity is in use. While researchers have not established an ironclad link
between the exposure to electromagnetic fields and ailments such as leukemia, the circumstantial
evidence concerns many people.
In scientific terms, human body can act as an antenna, as it has a higher conductivity for
electricity than air. Therefore, when conditions are right human body may have experienced a
small "tingle" of electric current from a poorly grounded electric appliance. As long as these
currents are very small there isn't much danger from electric fields, except for potential shocks. ,
Human body also has permeability almost equal to air, thus allowing a magnetic field to easily
enter the body. Unfortunately body cannot detect the presence of a strong magnetic field, which
could potentially do much more harm.
In terms of wireless technology, there are no confirmed health risks or scientific dangers from
infrared or radio frequency, with two known exceptions:
1. point-to-point lasers which can cause burns or blindness
2. prolonged microwave exposure which has been linked to cancer and leukemia
Therefore, most health concerns related to electromagnetic fields are due to electricity in day-to-
day use, such as computer monitors and TVs. These dangers, if any, are already in the home and
work place, and the addition of wireless technology should not be seen as an exceptional risk.
The strength of the electromagnetic field (EMF) decreases as the square of the distance from the
field source.
4.7 Security:
Electromagnetic frequencies currently have little legal status for protection and as such,
can be freely intercepted by motivated individuals. As presented earlier in the advantages and
disadvantages of infrared versus radio frequency transmission, what might be considered an
advantage to one method for transmission could turn out to be a disadvantage for security? For
example, because infrared is line-of-sight it has less transmission range but is also more difficult
to intercept when compared to radio frequency. Radio frequency can penetrate walls, making it
much easier to transmit a message, but also more susceptible to tapping.
A possible solution to security issues will likely be some form of data encryption. Data
encryption standards (DES) are also being quickly developed for the exchange of information over the
Internet, and many of these same DES will be applied to wireless technology.
4.8 Importance of Standards:
Several of the wireless devices demonstrated during the presentation have benefited to some
degree from standardization. For example, a universal IR remote was once priced at roughly
$100.00.The X10 devices that were demonstrated in the presentation not only rely on but have
benefited from the 60 HZ AC standard which applies to most of North America. As a result these
devices are now numerous and inexpensive. One final example demonstrating the importance of
standards is the relationship of augmentative alternative communication (AAC) devices to the
General Input Device Emulating Interface (GIDEI) standard. Any AAC device programmed to
use the GIDEI protocol can access any PC or Macintosh running the DOS, Windows, or
Macintosh version of Serial Keys.
CHAPTER – 5
LIQUID CRYSTAL DISPLAY
5.1 Introduction:
The most common application of liquid crystal technology is in liquid crystal displays
(LCDs). From the ubiquitous wrist watch and pocket calculator to an advanced VGA computer
screen, this type of display has evolved into an important and versatile interface.
A liquid crystal display consists of an array of tiny segments (called pixels) that can be
manipulated to present information. This basic idea is common to all displays, ranging from
simple calculators to a full color LCD television.
Why are liquid crystal displays important? The first factor is size. As will be shown in the
following sections, an LCD consists primarily of two glass plates with some liquid crystal
material between them. There is no bulky picture tube. This makes LCDs practical for
applications where size (as well as weight) is important. In general, LCDs use much less power
than their cathode-ray tube (CRT) counterparts. Many LCDs are reflective, meaning that they
use only ambient light to illuminate the display. Even displays that do require an external light
source (i.e. computer displays) consume much less power than CRT devices.
Liquid crystal displays do have drawbacks, and these are the subject of intense research.
Problems with viewing angle, contrast ratio, and response time still need to be solved before the
LCD replaces the cathode-ray tube. However with the rate of technological innovation, this day
may not be too far into the future.
5.2 Interfacing LCD to the Microcontroller:
This is the first interfacing example for the parallel port .This is example does not use the
Bi-directional feature found on newer ports, thus it should work with most, if no all parallel ports
.It however does not show the use of the status port as an input . So what are we interfacing? A
16 character X2 line LCD Module to the Parallel port .These LCD modules are very common
these days , and are quite simple to work with ,as all the logic required them is on board
5.3 Features:
Interfacing with either 4 bit or 8 bit microprocessor
Display data RAM
80 X 8 bits( 80 characters)
160 different 5 X 7 dot-matrix character patterns
8 different user programmed 5 X 7 dot- matrix patterns
Display data RAM and character generator RAM may be accessed by the
microprocessor.
Numerous instructions like Clear, Display, Cursor Home, Display ON/OFF, Cursor.
5.4 DIAGRAM:
Figure 10 Liquid Crystal Display
5.5 PIN DIAGRAM:
Figure 11 Pin diagram of 2x16 LCD Display
CHAPTER – 6
VISITORS’ COUNTER
6.1 Introduction:
Visitors’ counting is not limited to the entry/exit point of a company but has a wide range
of applications that provide information to management on the volume and flow of people
throughout a location. A primary method for counting the visitors involves hiring human auditors
to stand and manually tally the number of visitors who pass by a certain location. But human-
based data collection comes at great expense. Here is a low-cost microcontroller based visitor
counter that can be used to know the number of persons at a place.
All the components required are readily available in the market and the circuit is easy to build..
Enter T1
Logic control circuit
Micro-controller
Supply
TX1
TX2 T2
Exit
Figure 12 Transmitter &Receiver Setup
Fig. 12 shows the transmitter-receiver set-up at the entrance-cum-exit of the passage
along with block diagram two similar sections detect interruption of the IR beam and generate
clock pulse for the microcontroller. The microcontroller controls counting and displays the
number of persons present inside the hall. Two IR transmitter-receiver pairs are used at the
passage: one pair comprising IR transmitter IR TX1 and receiver phototransistor T1 is installed
at the entry point of the passage, while the other pair comprising IR transmitter IR TX2 and
phototransistor T2 is installed at the exit of the passage. The IR signals from the IR LEDs should
continuously fall on the respective phototransistors, so proper orientation of the transmitters and
phototransistors is necessary.
6.2How the People Counter Works?
IR technology is based on the optical time of flight (TOF) principle, whereby an active, non-
scanning light source emits modulated near-infrared light. The phase shift between the light emitted by
the source and the light reflected by the persons and objects in the field of view is measured to create a
real-time topographic image of the monitored area. By means of time-of-flight measurement and
sophisticated embedded algorithms, IRsensor measures and processes 3D data, in order to detect and
count the number of people in a specific area and track the direction of their movements.
6.3 Unparalleled Accuracy >99%
Sophisticated algorithms and extensive testing ensure reliable segmentation, tracking and
counting of people in order to minimize counting errors which commonly occur with most other people
counting systems on the market, and which result in unreliable data.
The People Counter’s unique segmentation and tracking ability allows for highly accurate and more
reliable data than passive infrared imager, scanner or video-based 2D systems on the market.
6.4 Easy Installation and Integration:
The People Counter requires only minimal changes to the existing infrastructure. Typically
installed above entrance doors or turnstiles, the People Counter reliably detects and counts each person
entering and exiting the room or building in real-time, and provides accurate occupancy monitoring data.
For queue management and wait time determination applications, multiple People Counters are installed
onto the ceiling to determine queue duration.
6.5Advantages:
Embedded Software
The sensor does not require any additional controllers to process the data it captures for most of its appli-
cations. For occupancy monitoring applications, the data provided by the People Counter can
automatically trigger energy saving or climate control measures.
Semi-Automatic Calibration
After configuring basic data such as detection area and mounting height, the sensor calibrates the
detection area within a few seconds. During this calibration the sensor surveys the empty detection zone
and captures the presence of fixed objects and walls.
Self-Diagnostics
A self-diagnostic routine runs at start-up and is regularly repeated to detect any sensor malfunction. The
results are provided through a web interface, status LEDs and digital outputs.
Reliability in Changing Light Conditions
Since the sensor emits its own illumination, the detection area can be lit normally, or be pitch black
without influencing its measurement.
6.4 Schematic Diagram:
Figure13: Schematic Diagram
APPENDIX
SOURCE CODE
# define F_CPU 800000UL
#include<avr/io.h>
#include<stdio.h>
#include<avr/interrupt.h>
#include<util/delay.h>
int count=0;
static int usart_putchar(char c, FILE *stream);
static FILE mystdout = FDEV_SETUP_STREAM(usart_putchar,
NULL,_FDEV_SETUP_WRITE);
static int usart_putchar(char c, FILE *stream)
{
if (c == '\r')
usart_putchar(' ', stream);
loop_until_bit_is_set(UCSRA, UDRE);
UDR = c;
return 0;
}
int a=0,b=0;
ISR(INT0_vect)
{
a=1;
printf(" INTERRUPT \n\r");
}
ISR(INT1_vect)
{
b=1;
// printf(" INTERRUPT \n\r");
}
void port_init(void)
{
PORTB = 0x00;
DDRB = 0xFF; //MISO line i/p, rest o/p
PORTC = 0x00;
DDRC = 0xFF;
PORTD = 0xff;
DDRD = 0b00000010;
}
//UART0 initialize
// desired baud rate: 19200
// actual: baud rate:19231 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
UCSRB = 0x00; //disable while setting baud rate
UCSRA = 0x00;
UCSRC = (1 << URSEL) | 0x06;
UBRRL = 0x33; //set baud rate lo
UBRRH = 0x00; //set baud rate hi
UCSRB = 0x18;
//UCSRB=0x98;//enabling receiving interrupts
}
//call this routine to initialize all peripherals
void init_devices(void)
{
cli();
port_init();
uart0_init();
//INT1.INT0.-.-.-.-.-.-.-IVSEL.IVCE
GICR=0b11000000;
MCUCR=0b00001010;
sei();
}
int main()
{
init_devices();
stdout = &mystdout;
printf(" HOME AUTOMATION USING ZIGBEE \n\r");
sei();
while(1)
{
if(a==1)
{
count++;
//printf("%d",count);
_delay_ms(20);
a=0;
}
else
{
a=0;
_delay_ms(20);
}
if(b==1)
{
count--;
//printf("%d",count);
_delay_ms(20);
b=0;
}
else
{
b=0;
_delay_ms(20);
}
if(count>=1)
{
PORTB=0xFF;
printf("TOTAL COUNT=%d\n\r",count);
printf("STATUS::LAMPS AND FANS ON\n\r");
_delay_ms(2000);
}
else
{
PORTB=0x00;
printf("TOTAL COUNT=%d\n\r",count);
printf("STATUS::LAMPS AND FANS OFF\n\r");
_delay_ms(2000);
}
}
}
RESULT:
By using this we can implement a power management system for shopping malls with bidirectional visitors counting.
