INDIVIDUAL CONTROL HOME

AUTOMATION SYSTEM

BY

OLAFUSI MICHAEL OLALEKAN

EEE/04/2995

SUBMITTED TO

THE DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING,

FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE.

IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE

AWARD OF BACHELOR OF ENGINEERING.

OCTOBER, 2009

CERTIFICATION

This is to certify that this project, the entire design and construction of the home automation

system was carried out and submitted as true work of OLAFUSI MICHAEL OLALEKAN of

matriculation number EEE/04/2995 under the supervision of Engineer O. E. Bejide of the

Department of Electrical and Electronics Engineering, Federal University of Technology,

Akure in partial fulfilment of the requirements for the award of Bachelor of Engineering in

Electrical Electronics Engineering.

_____________________ _____________________

Engineer O. E. Bejide Date (Project Supervisor)

______________________ ______________________

Dr. A. O. Melodi Date (Head of Department)

_______________________ _____________________

External Supervisor Date

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DEDICATION

To God Almighty for His provision and grace

To my parents for their constant vital support

To my siblings for their care and place

Do I dedicate this report

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ACKNOWLEDGEMENT

I cannot but acknowledge the unquantifiable help God gave me throughout this

project work, always showing up whenever I got to the end of my line and felt like changing

the project to a simpler one. Most remarkable was the breakthrough He gave me when I was

stuck at one PIC C code function for a month!

I am deeply indebted to my parents and siblings for their constant support especially

in circumstances where I find it hard to even convince myself that my request for help is fair

and reasonable. I am equally indebted my very understanding, fatherly and enviable project

supervisor, Engineer O. E. Bejide who is always willing to go above and beyond in

counselling and supervising me.

I could not have been able to understand how to go about the vital aspect of the

project work if not for the supervisory assistance of my friend and colleague, Ayoade

Adewole (really, all aspect of my project work was vital). I must also acknowledge my

colleagues who over the four years we have been together, in ways they themselves do not

understand, have been the vital components of my educational and personal growth which

also greatly rubbed on my successful completion of this project work.

I greatly appreciate the tripartite support and nourishment I enjoyed from the entire

family of the Chapel of Faith, especially through Uncle Victor Omololu, Aunt Patience

Omololu and their ministry. I must also acknowledge the spiritual oversight of the two

chaplains whom I have been under throughout my five year undergraduate study, Rev

Gbenga Olagunju and Rev. Timothy Abi-Abiola.

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ABSTRACT

This project involves the design and construction of an individual control home

automation system using RS232, GSM technology and a microcontroller.

Home automation is the automatic or semi-automatic control and monitoring of

household appliances and residential house features like doors, gate and even the windows.

This project is a demonstration of how to design and build a multi purpose remotely

controlled system that can switch OFF and ON any electrical household appliance (including

the security light), by dialling a phone already interfaced via RS232 to a microcontroller that

controls a relay for the automatic switching on and off of the appliance and the phone will

send a feedback short message service text indicating the new state of the appliance, whether

switched ON or OFF.

The results of this project show that a microcontroller is a very powerful device for

building smart electronic devices that can automatically control electrical appliances, with

little circuitry complexities and components.

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TABLE OF CONTENTSPROJECT REPORT....................................................................................................................iCERTIFICATION......................................................................................................................iiDEDICATION..........................................................................................................................iiiACKNOWLEDGEMENT........................................................................................................ivABSTRACT...............................................................................................................................vTABLE OF CONTENTS..........................................................................................................viTABLE OF FIGURES............................................................................................................viiiLIST OF TABLES....................................................................................................................ix

CHAPTER ONE........................................................................................................................1INTRODUCTION......................................................................................................................1

1.1 AUTOMATION ..........................................................................................................21.1.1 Office automation...............................................................................................31.1.2 Building automation...........................................................................................31.1.3 Power automation...............................................................................................41.1.4 Home automation................................................................................................4

1.2 PROJECT AIM...........................................................................................................41.3 PROJECT OBJECTIVE.............................................................................................51.4 PROJECT SCOPE AND LIMITATION.....................................................................51.5 PROJECT JUSTIFICATION......................................................................................51.6 REPORT LAYOUT.....................................................................................................6

CHAPTER TWO.......................................................................................................................7LITERATURE REVIEW...........................................................................................................7

2.1 HISTORY OF HOME AUTOMATION.....................................................................7 2.2 HOME AUTOMATION SYSTEMS..........................................................................7

2.3 HOME AUTOMATION STANDARDS....................................................................92.3.1 INSTEON standard...........................................................................................102.3.2 European Home Systems (EHS) protocol........................................................112.3.3 ZigBee standard................................................................................................122.3.4 KNX .................................................................................................................132.3.5 Z-Wave standard...............................................................................................152.3.6 X10 standard.....................................................................................................182.3.7 LonWorks .........................................................................................................202.3.8 ONE-NET standard...........................................................................................202.3.9 Universal Powerline Bus...................................................................................22

2.4 HOME AUTOMATION IMPLEMENTATION PLATFORMS.................................242.4.1 Powerline communication..................................................................................242.4.2 RS232.................................................................................................................252.4.3 Ethernet...............................................................................................................292.4.4 Bluetooth.............................................................................................................302.4.5 Infrared...............................................................................................................312.4.6 GSM....................................................................................................................312.4.7 Microcontroller...................................................................................................32

2.3.7.1 Von-Neumann architecture.........................................................................332.3.7.2 Harvard architecture...................................................................................33

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CHAPTER THREE..................................................................................................................35METHODOLOGY ..................................................................................................................35

3.1 PRELIMINARY CONSIDERATIONS......................................................................353.1.1 Selection of implementation platform................................................................353.1.2 Selection of hardware components.....................................................................36

3.2 SYSTEM DESIGN......................................................................................................363.2.1 PIC18F4455.........................................................................................................37

3.2.1.1 Central Processing Unit (CPU)..................................................................383.2.1.2 Random Access Memory (RAM)..............................................................393.2.1.3 Read Only Memory (ROM).......................................................................393.2.1.4 Input and Output ports (I/O)......................................................................39

3.2.2 PIC18F4455 architecture...................................................................................403.2.3 PIC18F4455 programming................................................................................433.2.4 Nokia 6021.........................................................................................................443.2.5 HIN232..............................................................................................................453.2.6 Relay..................................................................................................................47

CHAPTER FOUR....................................................................................................................49DESIGN AND IMPLEMENTATION......................................................................................49

4.1 BUILDING THE POWER SUPPLY AND INTERFACING THE RELAY.............504.2 SERIAL COMMUNICATION BETWEEN THE MICROCONTROLLER AND

NOKIA 6021............................................................................................................514.3 PROGRAMMING THE MICROCONTROLLER...................................................524.4 TESTING THE COMPLETE DESIGN AND CASING...........................................53

CHAPTER FIVE......................................................................................................................57CONCLUSION AND RECOMMENDATION........................................................................57

5.1 CONCLUSION..........................................................................................................575.2 RECOMMENDATION..............................................................................................57

REFERENCES.........................................................................................................................59APPENDIX I: Bill of components...........................................................................................61APPENDIX II: The PIC C code for programming the PIC4455 in CCS C compiler..............62

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TABLE OF FIGURES

Figure 2.1: Straight cable connection between RS232 DB9 DTE and RS232 DB9 DCE.......26

Figure 2.2: Straight cable connection between RS232 DB25 DTE and RS232 DB25 DCE...26

Figure 2.3: Straight cable connection between RS232 DB9 DTE and RS232 DB25 DCE.....27

Figure 2.4: Crossover cable connection between DB9 DTE and DB9 DCE...........................27

Figure 2.5: Crossover cable connection between DB25 DCE and DB25 DCE.......................28

Figure 2.6: Crossover cable connection between DB9 DCE and DB9 DCE...........................28

Figure 3.1: Block diagram of the home automation system....................................................37

Figure 3.2: Interactions between the main microcontroller parts............................................38

Figure 3.3: 40-Pin PIC18F4455 microcontroller.....................................................................40

Figure 3.4: PIC18F4455 block diagram...................................................................................42

Figure 3.5: CCS C compiler IDE interface..............................................................................43

Figure 3.6: MikroElectronika programmer interface...............................................................44

Figure 3.7: Nokia 6021 mobile phone......................................................................................45

Figure 3.8: HIN232 pinout.......................................................................................................46

Figure 4.1: Flow chart of the design........................................................................................49

Figure 4.2: The power supply...................................................................................................50

Figure 4.3: The RS232 to microcontroller portion of the design.............................................52

Figure 4.4: The complete home automation system circuit (controlling lighting fixture).......55

Figure 4.5: The individual control home automation system..................................................56

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LIST OF TABLES

Table 2.1: List of X10 four bit commands...............................................................................19

Table 3.1: HIN232 pin descriptions.........................................................................................46

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CHAPTER ONE

INTRODUCTION

Imagine how helpful it will be to be able to switch on your air conditioning

system ten minutes before you get home on a hot afternoon in January. How about

having a security system that will detect smoke, excessive electrical power usage,

burglar attempts and unauthorized movements in your house and alert you? This is

what home automation is about and there is no end to its application. In fact,

sophisticated home automation systems are now being developed that can maintain an

inventory of household items, record their usage through an RFID (Radio Frequency

Identification) tag, and prepare a shopping list or automatically order replacements.

Home automation has made it possible to have what is often referred to as a

'smart home', a home that can detect and identify you, automatically adjust the

lighting to your predefined taste, open doors automatically, play your favourite music,

water your flowers in the morning, switch on the security lights at night and switch

them off in the morning, heat water for bathe and tea, stream to you anywhere in the

world via the internet a live video of what is happening in and around your house. It

makes it possible to link lighting, entertainment, security, telecommunications,

heating, and air conditioning into one centrally controlled system. This allows you to

make your house an active partner in managing your busy life.

Nowadays, you can hardly find a house without a home automation system

which can range from the remote for the television, burglar alarm and hi-tech security

gates, to an automated air conditioning system that maintains the temperature at a

predefined value.

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1.1 AUTOMATION

Automation is the use of control systems and information technology to

control equipment, industrial machinery and processes, reducing the need for human

intervention. In the scope of industrialization, automation is a step beyond

mechanization. Mechanization provided human operators with machinery to assist

them with the physical requirements of work while automation greatly reduces the

need for human sensory and mental requirements as well (Wikipedia, 2009).

Automation plays an increasingly important role in the global economy

and in daily experience. Engineers strive to combine automated devices with

mathematical and organizational tools to create complex systems for a rapidly

expanding range of applications and human activities. Many roles for humans in

industrial processes presently lie beyond the scope of automation. Human-level

pattern recognition, language recognition, and language production ability are well

beyond the capabilities of modern mechanical and computer systems. Tasks requiring

subjective assessment or synthesis of complex sensory data, such as scents and

sounds, as well as high-level tasks such as strategic planning, currently require human

expertise.

Automation has had a notable impact in a wide range of highly visible

industries beyond manufacturing. Once ubiquitous telephone operators have been

replaced largely by automated telephone switchboards and answering machines.

Medical processes such as primary screening in electrocardiograph or radiography

and laboratory analysis of human genes, blood plasmas, cells, and tissues are carried

out at much greater speed and accuracy by automated systems. Automated teller

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machines have reduced the need for bank visits to obtain cash and carry out

transactions. In general, automation has been responsible for the shift in the world

economy from agrarian to industrial in the 19th century and from industrial to services

in the 20th century.

1.1.1 Office automation

Office automation refers to the varied computer machinery and software

used to digitally create, collect, store, manipulate, and relay office information needed

for accomplishing basic tasks and goals. Raw data storage, electronic transfer, and the

management of electronic business information comprise the basic activities of an

office automation system, office automation helps in optimizing or automating

existing office procedures.

1.1.2 Building automation

Building automation describes the functionality provided by the control of

a building. The control system is a computerized, intelligent network of electronic

devices, designed to monitor and control the mechanical and lighting systems of a

building. A building automation system is an example of a distributed control system.

The building automation system (BAS) core functionality keeps the building climate

within a specific range, provides lighting based on an occupancy schedule, and

monitors system performance and device failures and provides email and/or text

notifications to building engineering staff. The BAS functionality reduces building

energy and maintenance costs when compared to a non-controlled building.

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1.1.3 Power automation

Power automation is the automated control and monitoring of power

plants, substations and transformers for effectiveness, efficiency and fault detection. It

has made it possible to have a reliable municipal or national electricity system, which

often comprises remote and hard-to-reach transformers and power sub-system units. It

makes it possible to monitor different power units, relay their status and health

information, and even carry out fault detection and correction without human

interference.

Example of power automation system is the Supervisory Control and Data

Acquisition (SCADA) system.

1.1.4 Home automation

Home automation may designate an emerging practice of increased

automation of household appliances and features in residential dwellings, particularly

through electronic means that allow for things impracticable, overly expensive or

simply not possible in recent decades. Home automation includes all that a building

automation provides like climate controls, door and window controls, and in addition

control of multimedia home theatres, pet feeding, plant watering and so on. But there

exists a difference in that home automation emphasizes more on comforts through

ergonomics and ease of operation.

1.2 PROJECT AIM

The aim of this project is to design and construct a home automation

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system that will remotely switch on or off any household appliance connected to it,

using a microcontroller, voice dial on phone, and short message service for feedback.

1.3 PROJECT OBJECTIVE

The objective of this project is to implement a low cost, reliable and

scalable home automation system that can be used to remotely switch on or off any

household appliance, using a microcontroller to achieve hardware simplicity, low cost

short message service (SMS) for feedback and voice dial from any phone to toggle

the switch state.

1.4 PROJECT SCOPE AND LIMITATION

This project work is complete on its own in remotely and automatically

switching on and off of any electrical appliance not limited to household appliances,

and sends a feedback message indicating the new present state of the appliance. It

does not implement control of multiple appliances or automatic detection of faults in

the controlled appliance.

1.5 PROJECT JUSTIFICATION

This project is of contributory knowledge to the development and

implementation of home automation systems in Nigeria using low cost, locally

available components like microcontroller, free voice dial service (popularly referred

to as 'flashing') and very cheap short message service (SMS) text.

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1.6 REPORT LAYOUT

The entire project is composed of five chapters, each covering a section of

the work as summarized below:

• Chapter one gives an introduction to automation as a whole and the

different types of automation.

• Chapter two covers an extensive literature review of previous works on

home automation systems, the different established standards and

protocols, and the platforms over which home automation can be

implemented.

• Chapter three highlights the project methodology, giving reasons for choice

of specific platforms and components, and also, comprehensive details on

both hardware components and communication services used.

• Chapter four is on the project design and implementation with clear

practical details of the project design, construction, testing, microcontroller

coding and debugging. Special emphasis is also made on the flexibility and

scalability of the project work with real life illustration.

• Chapter five is on the conclusion and recommendations based on the

project work with emphasis on the reliability, maintainability and

flexibility of the design. Also, recommendations based on the challenges

encountered and further possible development of the project work are

enumerated.

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CHAPTER TWO

LITERATURE REVIEW

2.1 HISTORY OF HOME AUTOMATION

Home automation has been around since the world war 1 (1914), in fact,

the television remote (a simple home automation system) was patented in 1893

(Wikipedia, 2009). Since then different home automation systems have evolved with a

sharp rise after the second World War. It's growth has been through various informal

research and designs by technology enthusiasts who want a better way of getting

things done at home without much effort on their part. The systems evolved from one

that can automatically do routine chores like switch on and off security lights, to more

sophisticated ones that can adjust lighting, put the television channel to favourite

station and control doors.

2.2 HOME AUTOMATION SYSTEMS

Home automation systems may designate electronic systems in homes and

residential buildings that make possible the automation of household appliances. The

new stream of home automation systems has developed into a vast one and the current

market is flooded with a flurry of home automation systems and device

manufacturers.

The types of home automation systems based on their control systems are:

1. Individual Control Systems

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These types were the first to hit the market in the early years, here each

device like the heater or the air conditioner will have an independent control

dedicated to it.

2. Distributed Control Systems

The main feature of these type of systems is emergency shut-down. With

this system you can preset or change the control parameters of several

similar devices, for example, the thermostat of several air conditioners and

their ON/OFF timings.

3. Central Control Systems

These are computerized systems programmed to handle all functions of

multiple utilities like air conditioning system, home entertainments, doors,

windows, refrigerators and cooking systems, all at the same time regardless

of whether you are at home or away. You can connect to the control system

through telephone or internet from anywhere in the world.

The types of home automation systems based on the carrier mode are:

1. Powerline carrier Systems

The least expensive type of home automation system operates over the

home's existing wiring, or powerline carrier. These can range from X10-

based lamp timers, to more sophisticated systems that require installation by

a trained professional.

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2. Wireless systems

Also available are wireless home automation systems that utilize radio-

frequency technology. They are often used to operate lights, sometimes in

conjunction with a hardwired lighting control system.

3. Hardwired systems

Wired, or “hardwired” home control systems are the most reliable and

expensive. These systems can operate over high-grade communications

cable such as Category 5 or 5e, or their own proprietary “bus” cable. That is

why it is best to plan for them when a house is being constructed. Hardwired

systems can perform more tasks at a time and do them quickly and reliably,

making them ideal for larger homes. They can also integrate more systems

in the home, effectively tying together indoor and outdoor lighting, audio

and video equipment, security system, even the heating and cooling system

into one control package that will be easy and intuitive to operate.

4. Internet Protocol control system

Internet Protocol (IP) control automation system uses the internet, gives

each device under its control an Internet Protocol address, and creates a

local area network (LAN) in the home. Hence, the home can be interacted

with over the internet with possibility of live video streaming and real-time

control.

2.3 HOME AUTOMATION STANDARDS

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There are many established industry standards for home automation

systems and are implemented over the various carrier modes ranging from powerline

to wireless. The popular and major standards are INSTEON, European Home

Systems (EHS), ZigBee, KNX, Z-Wave, X10, LonWorks, ONE-NET and Univerasl

Powerline Bus (UPB).

2.3.1 INSTEON standard

INSTEON standard is a dual-band mesh topology employing ac-power

lines and a radio frequency (RF) protocol to communicate with and automate home

electronic devices and appliances, which normally work independently. It is a home

automation networking technology invented by SmartLabs Inc. INSTEON was

developed, based on the X10 model, for control and sensing applications in the home

(Wikipedia, 2009).

INSTEON is designed to enable simple devices to be networked together

using the powerline and/or radio frequency (RF). All INSTEON devices are peers,

meaning each device can transmit, receive, and repeat any message of the INSTEON

protocol, without requiring a master controller or complex routing software.

INSTEON is not only an effective system for connecting lighting switches and loads

without extra wiring, but it also forms the basis for a more sophisticated home

automation network.

The following are the possible applications of INSTEON:

• Scene and remote control lighting,

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• Security alarm interfaces and sensors,

• Home sensors (e.g. water, humidity, temperature),

• Access control (e.g. door locks),

• Heating, ventilating and air cooling (HVAC) control,

• Audio-video control, and

• Appliance management.

2.3.2 European Home Systems (EHS) protocol

The European home systems (EHS) protocol was aimed at home

appliances control and communication using power line communication (PLC).

Developed by EHSA (European Home Systems Association) it was merged with two

other protocols to form the KNX protocol, which complies with CENELEC norm EN

50090 standard and had a chance to be a basis for the first open standard for home

and building control (Wikipedia, 2009).

The areas of application of EHS are:

• Heating, ventilating and air cooling (HVAC) control,

• Scene and remote control lighting, and

• Appliance management.

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2.3.3 ZigBee standard

ZigBee is a specification for a suite of high level communication protocols

using small, low-power digital radios based on the IEEE 802.15.4-2003 standard for

wireless personal area networks (WPANs), such as wireless headphones connecting

with cell phones via short-range radio. The technology defined by the ZigBee

specification is intended to be simpler and less expensive than other WPANs such as

Bluetooth. ZigBee is targeted at radio frequency (RF) applications that require a low

data rate, long battery life, and secure networking (Wikipedia, 2009).

ZigBee is a low-cost, low-power, wireless mesh networking standard. The

low cost allows the technology to be widely deployed in wireless control and

monitoring applications, the low power-usage allows longer life with smaller

batteries, and the mesh networking provides high reliability and larger range.

ZigBee operates in the industrial, scientific and medical (ISM) radio

bands; 868 MHz in Europe, 915 MHz in the USA and Australia, and 2.4 GHz in most

jurisdictions worldwide. ZigBee chip vendors typically sell integrated radios and

microcontrollers with between 60K and 128K flash memory, such as the Freescale

MC13213, the Ember EM250 and the Texas Instruments CC2430. Radios are also

available as stand-alone to be used with any processor or microcontroller. Generally,

the chip vendors also offer the ZigBee software stack, although independent ones are

also available. The ZigBee Alliance is a group of companies that maintain and publish

the ZigBee standard.

Typical areas of application of ZigBee are:

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• Home Entertainment and Control — Smart lighting, advanced

temperature control, safety and security, movies and music,

• Home Awareness — Water sensors, power sensors, smoke and fire

detectors, smart appliances and access sensors,

• Mobile Services — m-payment, m-monitoring and control, m-

security and access control, m-healthcare and tele-assist,

• Commercial Building — Energy monitoring, HVAC, lighting,

access control, and

• Industrial Plant — Process control, asset management,

environmental management, energy management, industrial device

control.

2.3.4 KNX

KNX is a standardised (EN 50090,ISO/IEC 14543), OSI-based network

communications protocol for intelligent buildings. KNX is the successor to, and

convergence of, three previous standards: the European Home Systems Protocol

(EHS), BatiBUS, and the European Installation Bus (EIB). The KNX standard is

administered by the Konnex Association (Wikipedia, 2009).

This standard is based on the communication stack of EIB but enlarged

with the physical layers, configuration modes and application experience of BatiBUS

and EHS.

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KNX defines several physical communication media:

• Twisted pair wiring

• Powerline networking

• Radio

• Infrared

• Ethernet (also known as EIBnet/IP or KNXnet/IP)

KNX is designed to be independent of any particular hardware platform. A

KNX Device Network can be controlled by anything from an 8-bit microcontroller to

a PC, according to the needs of a particular implementation. The most common form

of installation is over twisted pair medium.

KNX is approved as an open standard to International standard (ISO/IEC

14543-3) European Standard (CENELEC EN 50090 and CEN EN 13321-1) and

China Guo Biao(GB/Z 20965).

KNX has more than 100 members/manufacturers including ABB, Bosch,

Miele & Cie KG, ON Semiconductor, Schneider Electric Industries S.A., Siemens,

Uponor Corporation and Jung.

There are three categories of KNX device:

1. A-mode or "Automatic mode" devices automatically configure

themselves, and are intended to be sold to and installed by the end user.

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2. E-mode or "Easy mode" devices require basic training to install. Their

behaviour is pre-programmed, but has configuration parameters that need

to be tailored to the user's requirements.

3. S-mode or "System mode" devices are used in the creation of bespoke

building automation systems. S-mode devices have no default behaviour,

and must be programmed and installed by specialist technicians.

2.3.5 Z-Wave standard

The Z-wave is a wireless communications proprietary standard designed

for home automation, specifically to remote control applications in residential and

light commercial environments. This technology, which is developed by Sigma

designs' Zensys, uses a low power RF radio embedded or retrofitted into home

electronics devices and systems, such as lighting, home access control, entertainment

systems and household appliances. The technology has been standardized by the Z-

Wave Alliance, an international consortium of manufacturers that oversees

interoperability between Z-Wave products and enabled devices (Wikipedia, 2009).

Z-Wave is a mesh networking technology where each node or device on

the network is capable of sending and receiving control commands through walls or

floors and around household obstacles or radio dead spots that might occur in the

home. Z-Wave devices can work singly or in groups, and can be programmed into

scenes or events that trigger multiple devices, either automatically or via remote

control.

Z-Wave is a low-power wireless technology designed specifically for

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remote control applications. Unlike Wi-Fi and other IEEE 802.11-based wireless

LAN systems that are designed primarily for high-bandwidth data flow, the Z-Wave

RF system operates in the sub Gigahertz frequency range and is optimized for low-

overhead commands such as on-off (as in a light switch or an appliance) and raise-

lower (as in a thermostat or volume control), with the ability to include device

metadata in the communications. Because Z-Wave operates apart from the 2.4 GHz

frequency of 802.11 based wireless systems, it is largely impervious to interference

from common household wireless electronics, such as Wi-Fi routers, cordless

telephones and Bluetooth devices that work in the same frequency range. This

freedom from household interference allows for a standardized low-bandwidth

control medium that can be reliable alongside common wireless devices. On other

hand, 2.4 GHz frequency usage allows unlicensed devices usage in most countries;

this is convenient to customers and allows wider technology adoption and reduced

deployment costs. This could be not true for other frequencies and could easily turn

into a strong drawback if licensing is required or frequency is occupied. That's one of

reason why competing 2.4 GHz technologies became so popular.

As a result of its low power consumption and low cost of manufacture, Z-

Wave is easily embedded in consumer electronics products, including battery

operated devices such as remote controls, smoke alarms and security sensors. Z-Wave

is currently supported by over 200 manufacturers worldwide and appears in a broad

range of consumer products in the U.S. and Europe.

Some common applications for Z-Wave include:

• Remote Home Control And Management – By adding Z-Wave to

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home electronics such as lighting, climate and security systems, it is

possible to control and monitor these household functions via remote

control, based on manual or automated decisions. The control can be

applied to a single device or group of devices, in a single room or zone or

throughout the entire home. One of the benefits of Z-Wave over power

line communication technologies is the ability to function in older houses

lacking a neutral wire. Z-Wave devices can also be monitored and

controlled from outside of the home by way of a gateway that combines

Z-Wave with broadband Internet access.

• Energy Conservation – Z-Wave is envisioned as a key enabling

technology for energy management in the green home. As an example, Z-

Wave-enabled thermostats are able to raise or lower automatically, based

on commands from Z-Wave enabled daylight sensors. Grouped scene

controls can ensure that unnecessary energy consumption is minimized by

various all-off states for systems throughout the home, such as lighting,

appliances and home entertainment systems.

• Home Safety And Security Systems – Because Z-Wave can

transceive commands based on real time conditions, and is able to control

devices in intelligent groupings, it allows novel extensions of traditional

home security concepts. As an example, the opening of a Z-Wave enabled

door lock can de-activate a security system and turn on lights when

children arrive home from school, and send a notification to a parent's PC

or cell phone via the Internet. Opening a Z-Wave enabled garage door can

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trigger exterior and interior home lights, while a Z-Wave motion detector

can trigger an outdoor security light and a webcam, which would allow

the end user to monitor the home while away.

• Home Entertainment – Z-Wave's ability to command multiple

devices as a unified event makes it well suited for home audio and video

applications. For example, a simple "Play DVD" command on the remote

control could turn on the needed components, set them to the correct

inputs and even lower motorized shades and dim the room lights. Z-

Wave's RF technology is also well suited as an evolution of conventional

Infrared (IR) based remote controls for home electronics, as it is not

constrained by IR's line of sight and distance limitations. In January of

2008, Zensys announced a single-chip solution that pairs Z-Wave with IR

control, positioning the technology as an all encompassing solution for

home remote controls.

2.3.6 X10 standard

X10 is an international and open industry standard for communication

among electronic devices used for home automation. It primarily uses power line

wiring for signalling and control, where the signals involve brief radio frequency

bursts representing digital information. X10 was developed in 1975 by Pico

Electronics of Glenrothes, Scotland, in order to allow remote control of home devices

and appliances. It was the first general purpose home automation network technology

and remains the most widely available. Although a number of higher bandwidth

alternatives exist including KNX, INSTEON, BACnet, and LonWorks, X10 remains

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popular in the home environment with millions of units in use worldwide, and

inexpensive availability of new components (Wikipedia, 2009).

Packets transmitted using X10 control protocol consist of a four bit house

code followed by one or more four bit unit code, finally followed by a four bit

command.

Table 2.1 : List of X10 four bit commands

Code Function Description

0 0 0 0 All Units OffSwitch off all devices with the house code indicated in the

message

0 0 0 1 All Lights OnSwitches on all lighting devices (with the ability to control

brightness)0 0 1 0 On Switches on a device0 0 1 1 Off Switches off a device0 1 0 0 Dim Reduces the light intensity0 1 0 1 Bright Increases the light intensity0 1 1 1 Extended Code Extension code

1 0 0 0 Hail RequestRequests a response from the device(s) with the house code

indicated in the message

1 0 0 1Hail

AcknowledgeResponse to the previous command

1 0 1 x Preset Dim Allows the selection of two predefined levels of light intensity

1 1 0 1 Status is OnResponse to the Status Request indicating that the device is

switched on1 1 1 0 Status is Off Response indicating that the device is switched off1 1 1 1 Status Request Request requiring the status of a device

19

2.3.7 LonWorks

LonWorks is a networking platform specifically created to address the

needs of control applications. The platform is built on a protocol created by Echelon

Corporation for networking devices over media such as twisted pair, power lines,

fibre optics, and radio frequency. It is used for the automation of various functions

within buildings such as lighting and HVAC (Heating, ventilating and air

conditioning).

This technology has its origins with chip designs, power line and twisted

pair, signalling technology, routers, network management software, and other

products from Echelon Corporation. Two physical layer signalling technologies,

twisted pair and power line carrier, are typically included in each of the standards

created around the LonWorks technology. The two-wire layer operates at 78 kbit/s

using differential manchester encoding, while the power line achieves either 5.4 or

3.6 kbit/s, depending on frequency. Additionally, the LonWorks platform uses an

affiliated Internet protocol (IP) tunnelling standard – ANSI/CEA-852 – in use by a

number of manufacturers to connect the devices on previously deployed and new

LonWorks-based networks to IP-aware applications or remote network management

tools. Most LonWorks-based control applications are being implemented with some

sort of IP integration, either at the user interface, application level or in the control

infrastructure. This is accomplished with web services or IP-routing products

available on the market (Wikipedia, 2009).

2.3.8 ONE-NET standard

20

ONE-NET is an open-source standard for wireless network designed for

low-cost, low-power (battery operated) control networks for applications such as

home automation, security and monitoring, device control, and sensor networks.

ONE-NET is not tied to any proprietary hardware or software, and can be

implemented with a variety of low-cost off-the-shelf radio transceivers and

microcontrollers from a number of different manufacturers (Wikipedia, 2009).

ONE-NET uses UHF ISM radio transceivers and currently operates in the

868 MHz and 915 MHz frequencies. The ONE-NET standard allows for

implementation on other frequencies, and some work is being done to implement it in

the 400 MHz and 2.4 GHz frequency ranges. It utilizes Wideband FSK (Frequency-

shift keying) to encode data for transmission and it features a dynamic data rate

protocol with a base data rate of 38.4 kbit/s. The specification allows per-node

dynamic data rate configuration for data rates up to 230 kbit/s.

ONE-NET supports star, peer-to-peer, and mesh networking topologies.

Star network topology can be used for lower complexity and cost of peripherals, and

also simplifies encryption key management. In peer-to-peer mode, a master device

configures and authorizes peer-to-peer transactions. The wireless mesh network mode

allows for repeating to cover larger areas or route around dead areas. Outdoor peer-to-

peer range has been measured to over 500 m, indoor peer-to-peer range has been

demonstrated from 60 m to over 100 m, and mesh mode can extend operational range

to several kilometers. Simple, block, and streaming transactions are supported.

Simple transactions typically use message types as defined by the ONE-NET protocol

to exchange sensor data such as temperature or energy consumption, and control data

21

such as on/off messages. Simple transactions use encryption techniques to avoid

susceptibility to replay attacks. Block transactions can be used to transmit larger

blocks of data than simple messages. Block transactions consist of multiple packets

containing up to 58 bytes per packet. Blocks transactions can transfer up to 65,535

bytes per block. Streaming transactions are similar in format to block transactions but

do not require retransmission of lost data packets.

ONE-NET is optimized for low power consumption such as battery-

powered peripherals. Low-duty-cycle battery-powered ONE-NET devices such as

window sensors, moisture detectors, etc. can achieve a three to five year battery life

with “AA” or "AAA" alkaline cells. Dynamic power adjustment allows signal

strength info to be used to scale back transmit power to conserve battery power. High

data rates and short packet sizes minimize transceiver on time. Further power

efficiency can be gained utilizing deterministic sleep periods for client devices.

2.3.9 Universal Powerline Bus

The Universal Powerline Bus (UPB) is an industry emerging standard for

communication among devices used for home automation. It uses powerline wiring

for signalling and control.

Household electrical wiring is used to send digital data between UPB

devices. While in the X10 protocol this digital data is encoded onto a 120 KHz carrier

which is transmitted as bursts during the relatively quiet zero crossings of the 50 or 60

Hz AC alternating current waveform, the UPB protocol works differently. The UPB

communication method consists of a series of precisely timed electrical pulses (called

22

UPB Pulses) that are superimposed on top of the normal AC power waveform (sine

wave). Receiving UPB devices can easily detect and analyse these UPB Pulses and

pull out the encoded digital information from them. UPB Pulses are generated by

charging a capacitor to a high voltage and then discharging that capacitor’s voltage

into the powerline at a precise time. This quick discharging of the capacitor creates a

large “spike” (or pulse) on the powerline that is easily detectable by receiving UPB

devices wired large distances away on the same powerline.

UPB controllers range from extremely simple plug-in modules to very

sophisticated whole house home automation controllers. The simplest controllers are

plug-in controllers that are recommended for a moderate amount of switches and

devices as it becomes cumbersome to control a wide range of devices. More

sophisticated controllers can control more units and/or incorporate timers that

perform pre-programmed functions at specific times each day. Units are also available

that use passive infrared motion detectors or photocells to turn lights on and off based

on external conditions. Finally, whole house home automation controllers can be fully

programmed. These systems can execute many different timed events, respond to

external sensors, and execute, with the press of a single button, an entire scene,

turning lights on, establishing brightness levels, and so on.

UPB was developed by PCS Powerline Systems of Northridge, California

and released in 1999. Based on the concept of the ubiquitous X10 standard, UPB has

an improved transmission rate and higher reliability. While X10 without specialised

firewalls has a reported reliability of 70-80%, UPB reportedly has a reliability of

more than 99% (Wikipedia, 2009).

23

2.4 HOME AUTOMATION IMPLEMENTATION PLATFORMS

Home automation can be implemented over a number of platforms

namely, Powerline, RS232 serial communication, Ethernet, Bluetooth, Infrared and

GSM. Each platform having its own peculiarity and area of application.

2.4.1 Powerline communication

Powerline communication is a system for carrying data on a conductor

also used for electrical power transmission. Though electrical power is transmitted

over high voltage transmission lines, distributed over medium voltage and used inside

buildings at lower voltages, powerline communication can be applied at each stage.

All powerline communication systems operate by impressing a modulated

carrier signal on the wiring system. Different types of powerline communications use

different frequency bands, depending on the signal transmission characteristics of the

power wiring used. Since the power wiring system was originally intended for

transmission of alternating current (AC) power, in conventional use, the power wire

circuits have only a limited ability to carry higher frequencies. The propagation

problem is a limiting factor for each type of powerline communications. Data rates

over a powerline communications system vary widely. Low-frequency (about 100 –

200 Khz) carriers impressed on high-voltage transmission lines may carry one or two

analog voice circuits, or telemetry and control circuits with an equivalent data rate of

a few hundred bits per second; however, these circuits may be many miles long.

24

2.4.2 RS232

The RS232 stands for recommended standard number 232. The serial ports

on most computers use a subset of the RS232 standard. The full RS232 standard

specifies a 25-pin "D" connector of which 22 pins are used. Most of these pins are not

needed for normal PC communications, and indeed, most new PCs are equipped with

male D type connectors having only 9 pins, trading off compatibility with the standard

against the use of less costly and more compact connectors.

In RS232, the communicating devices are referred to as Data Terminal

Equipment (DTE) and Data Communication Equipment (DCE). The DTE is an end

instrument that converts user information into signals or reconverts received signals

and uses the male connector. The DTE is the functional unit of a data station that

serves as a data source or a data sink and provides for the data communication control

function to be performed in accordance with link protocol. While the DCE is

communication link control device that provides the clock signal and uses the female

connector. The DTE ends the communication line, whereas the DCE provides a path

for communication. In connecting a DTE device to a DCE a straight pin-for-pin

connection is used. However, to connect two DCEs or DTEs the transmit and receive

lines must be crossed. The DTE is usually a computer or a terminal device and the

DCE is usually a modem.

Figures 2.1 – 2.3 shows the straight connections while figures 2.4 – 2.6

illustrate the cross-over cable connections.

25

Figure 2.1 : Straight cable connection between RS232 DB9 DTE and RS232 DB9 DCE

Figure 2.2 : Straight cable connection between RS232 DB25 DTE and RS232 DB25 DCE

26

Figure 2.3 : Straight cable connection between RS232 DB9 DTE and RS232 DB25 DCE

Figure 2.4 : Crossover cable connection between DB9 DCE and DB9 DCE

27

Figure 2.5 : Crossover cable connection between DB25 DCE and DB25 DCE

Figure 2.6 : Crossover cable connection between DB9 DCE and DB9 DCE

28

2.4.3 Ethernet

Ethernet defines a number of wiring and signalling standards for the

physical connection of two or more devices together. Ethernet was originally based on

the idea of computers communicating over a shared coaxial cable acting as a

broadcast transmission medium. The methods used show some similarities to radio

systems, although there are fundamental differences, such as the fact that it is much

easier to detect collisions in a cable broadcast system than a radio broadcast. The

common cable providing the communication channel was likened to the ether and it

was from this reference that the name "Ethernet" was derived (Wikipedia, 2009).

From this early and comparatively simple concept, Ethernet evolved into the complex

networking technology that today underlies most local area networks. The coaxial

cable was replaced with point-to-point links connected by Ethernet hubs and/or

switches to reduce installation costs, increase reliability, and enable point-to-point

management and troubleshooting. StarLAN was the first step in the evolution of

Ethernet from a coaxial cable bus to a hub-managed, twisted-pair network. The

advent of twisted-pair wiring dramatically lowered installation costs relative to

competing technologies, including the older Ethernet technologies. Through the

physical connection, Ethernet stations communicate by sending each other data

packets, blocks of data that are individually sent and delivered.

Despite the significant changes in Ethernet from a thick coaxial cable bus

running at 10 Mbits/s to point-to-point links running at 1 Gbit/s and above, all

generations of Ethernet (excluding early experimental versions) share the same frame

formats (and hence the same interface for higher layers), and can be readily

29

interconnected. And due to the ubiquity of Ethernet, the ever-decreasing cost of the

hardware needed to support it, and the reduced panel space needed by twisted pair

Ethernet, most manufacturers now build the functionality of an Ethernet card directly

into computer and laptop motherboards, eliminating the need for installation of a

separate network card.

2.4.4 Bluetooth

Bluetooth is an open wireless protocol for exchanging data over short

distances from fixed and mobile devices, creating personal area networks (PANs). It

was originally conceived as a wireless alternative to RS232 data cables. It can connect

several devices, overcoming problems of synchronization. It is a standard and a

communications protocol primarily designed for low power consumption, with a short

range (power-class-dependent: 1 meter, 10 meters, 100 meters) based on low-cost

transceiver microchips in each device. Bluetooth makes it possible for devices to

communicate with each other when they are in range. Because the devices use a radio

(broadcast) communications system, they do not have to be in line of sight of each

other.

Bluetooth uses a radio technology called frequency-hopping spread

spectrum, which chops up the data being sent and transmits chunks of it on up to 79

frequencies. In its basic mode, the modulation is Gaussian frequency-shift keying

(GFSK). It can achieve a gross data rate of 1 Mb/s. Bluetooth provides a way to

connect and exchange information between devices such as mobile phones,

telephones, laptops, personal computers, printers, Global Positioning Systems (GPS)

receivers, digital cameras, and video game consoles through a secure, globally

30

unlicensed Industrial, Scientific and Medical (ISM) 2.4 GHz short-range radio

frequency band. The Bluetooth specifications are developed and licensed by the

Bluetooth Special Interest Group (SIG). The Bluetooth SIG consists of companies in

the areas of telecommunication, computing, networking, and consumer electronics

(Wikipedia, 2009).

2.4.5 Infrared

Infrared (IR) radiation is electromagnetic radiation whose wavelength is

longer than that of visible light (400 – 700 nm), but shorter than that of microwave

radiation . It's wavelength spans between 750nm and 100 µm and is employed in

short-range communication among devices that conform to the standards published

by the Infrared Data Association (IrDA).

Remote controls and IrDA devices use infrared light-emitting diodes

(LEDs) to emit infrared radiation which is focused by a plastic lens into a narrow

beam. The beam is modulated, i.e. switched on and off, to encode the data. The

receiver uses a silicon photodiode to convert the infrared radiation to an electric

current. It responds only to the rapidly pulsing signal created by the transmitter, and

filters out slowly changing infrared radiation from ambient light. Infrared

communications are useful for indoor use in areas of high population density. IR does

not penetrate walls and so does not interfere with other devices in adjoining rooms.

Infrared is the most common way for remote controls to command appliances.

2.4.6 GSM

GSM which stands for Global System for Mobile Communication, is the

31

most popular standard for mobile phone communication in the world. It is used by

over three billion people across more than 212 countries and territories (Wikipedia,

2009).

GSM basically provides voice call and short message service (SMS). It

operates as a cellular network that mobile phones connect to by trying to search for

cells in their immediate vicinity. The modulation used in GSM is Gaussian minimum-

shift keying (GMSK), a kind of continuous-phase frequency shift keying. In GMSK,

the signal to be modulated onto the carrier is first smoothed with a Gaussian low-pass

filter prior to being fed to a frequency modulator, which greatly reduces the

interference to neighbouring channels (adjacent channel interference). GSM networks

operate in the 900 MHz or 1800MHz frequency bands in most countries of the world

except in few countries like USA and Canada where 850 and 1900 MHz bands are

used as the 900 and 1800 MHz bands were already allocated. The GSM technology

uses a 200 Khz radio frequency channels that are time division multiplexed to enable

up to eight users to access each carrier.

2.4.7 Microcontroller

A microcontroller is an inexpensive single-chip computer. Single-chip

computer means that the entire computer system lies within the confines of the

integrated circuit chip (Byte, 2002). The microcontroller on the encapsulated silver of

silicon has features similar to those of our standard personal computer. Its ability to

store and run unique programs makes it extremely versatile, and its ability to perform

maths and logic functions allows it to mimic sophisticated logic and electronic

circuits. Microcontrollers are used in automatically controlled products and devices,

32

such as automobile engine control systems, remote controls, office machines,

appliances, power tools and toys. Hence, microcontrollers due not function in

isolation, they accept input from one or more devices and provide output to other

devices within a given system. In fact, they are responsible for the intelligence in most

smart devices in the consumer market.

The microcontroller has two general architecture types that define its mode

of operation and design.

2.3.7.1 Von-Neumann architecture

This architecture has a single, common memory space where both program

instructions and data are stored. There is a single data bus which fetches both

instructions and data. And each time the CPU fetches a program instruction it may

have to perform one or more read/write operations to data memory space. It must wait

until these subsequent operations are complete before it can fetch and decode the next

program instruction. The advantage to this architecture lies in its simplicity and

economy. On some Von Neumann machines the program can read from and write to

CPU registers, including the program counter. This can be dangerous as you can point

the processor to memory blocks outside program memory space and careless

processor manipulation can cause errors which require a hard reset.

2.3.7.2 Harvard architecture

This architecture implements separate memory areas for program

instructions and data. There are two or more internal data buses which allow

simultaneous access to both instructions and data. The CPU fetches instructions on

33

the program memory bus. If the fetched instruction requires an operation on data

memory, the CPU can fetch the next program instruction while it uses the data bus for

its data operation. This speeds up execution time at the cost of more hardware

complexity. Most modern microcontrollers have the harvard architecture.

34

CHAPTER THREE

METHODOLOGY

In designing a home automation system, one or more suitable platforms are

used in order to build a reliable and flexible system that can be easily operated and

adapted for a new household appliance. Therefore, for the purpose of this project

some specific deliberate choices were made on the type of platforms, hardware

components and mode of operation of the home automation system.

3.1 PRELIMINARY CONSIDERATIONS

Before the actual design of the project work, specific deliberate choices in

selection of appropriate implementation platforms and hardware components were

made. Priority was given to low cost availability, reliability, flexibility and simplicity

in all these selections.

3.1.1 Selection of implementation platform

As already explained in the previous chapter, there are many platforms

over which a home automation system can be implemented. Of the currently available

platforms – Powerline, RS232, Ethernet, Bluetooth, Infrared, GSM and

Microcontroller; RS232, GSM and Microcontroller were found most appropriate due

to their low cost availability, reliability and simplicity when used for an individual

control home automation system which my project work is on. Powerline and

Ethernet is too expensive and complex for this kind of home automation system,

while Bluetooth and Infrared are unreliable.

35

3.1.2 Selection of hardware components

Each platform has a set of hardware components over which it is

implemented. For RS232, there are DB-9 and DB-25 connection cables, but DB-9

cable was found most appropriate because it is cheaper, more readily available, less

bulky and just sufficient for the designed system when compared with DB-25. For

GSM, there are GSM modems and phone brands, but Nokia 6021 was chosen due to

its low cost availability, ability to understand AT commands and availability of its

RS232 DB-9 cable. Finally, for Microcontroller, the popular ones are those produced

by Microchip, ATMEL, Motorola and Texas Instruments, of all these Microchip

manufactured PIC microcontroller was found most suitable due to its low cost

availability, and readily available programmers, compilers and flexibility.

3.2 SYSTEM DESIGN

The designed home automation system uses PIC18F4455 microcontroller,

Nokia 6021 mobile phone, RS232 standard for communication between the

microcontroller and mobile phone, HIN232 for interfacing the microcontroller, a relay

and a driver for interfacing the relay.

As illustrated in the block diagram shown in figure 3.1, when the Nokia

6021 receives the required signal, it communicates via the RS232 and HIN232 to the

PIC18F4455, the PIC18F4455 controls the relay state via a driver and this in turn

determines the state of the connected appliance, whether switched on or off.

36

Figure 3.1 : Block diagram of the home automation system

3.2.1 PIC18F4455

PIC18F4455 is manufactured by Microchip Incorporation based in United

States of America, and is one of their harvard architecture based microcontroller

series called PIC. PIC is generally assumed to mean “programmable interface

controller”. The PIC microcontroller contains a CPU (central processing unit), RAM

(random access memory), ROM (read-only memory), I/O (input/output) lines, serial

37

HIN232

PIC18F4455

SER

IAL

RELAY

DR

IVER

RS232

HOMEAPPLIANCE

AC LINE

and parallel ports, timers and sometimes other built in peripherals such as A/D

(analogue-to-digital) and D/A (digital-to-analogue) converters.

Figure 3.2 shows the interactions (data flow) between the main

microcontroller parts.

Figure 3.2 : Interactions between the main microcontroller parts

3.2.1.1 Central Processing Unit (CPU)

The CPU is responsible for all the computing, it fetches, decodes and

executes program instructions and directs the flow of data to and from memory. It

performs the calculations required by program instructions and places the results of

these calculations, if required, into memory space. Most CPUs are synchronous,

meaning that they depend on the cycles of a processor clock, this clock generates a

high-frequency square wave usually driven by a crystal, a RC (resistor capacitor) or

an external source. The clock is sometimes referred to as an oscillator. The clock

speed, or oscillation rate, is measured in megahertz (MHz) which represents one

million cycles/second.

38

3.2.1.2 Random Access Memory (RAM)

The RAM, random access memory, is used to write and read data values as

a program runs. RAM is volatile meaning that if the power supply to the

microcontroller is removed, its contents are lost. All variables used in a program are

allocated from the RAM. The time to retrieve information from RAM does not

depend upon the location of the information because RAM is not sequential, hence the

term random access. Most small PIC microcontrollers provide very little RAM which

forces you to write applications that use RAM wisely. Manipulating large data

structures and using pointers, re-entrant or recursive functions use large amounts of

RAM and are techniques which are generally avoided on microcontrollers

3.2.1.3 Read Only Memory (ROM)

The ROM, read only memory, is non-volatile memory used for program

information and permanent data. The microcontroller uses ROM memory space to store

program instructions it will execute when it is started or reset. Program instructions must be

saved in non-volatile memory so that they are not affected by loss of power, the

microcontroller usually cannot write data to program memory space.

3.2.1.4 Input and Output ports (I/O)

Without some means of getting information and signals in and out, the

microcontroller will have little or no use. Hence, the input and output ports are used to

pass data in and out of the microcontroller in a controlled manner, often according to

a standard protocol. The PIC microcontroller ports are of two types namely, serial and

parallel ports. They can operate in two main modes namely, synchronous and

39

asynchronous modes. The parallel I/O ports require a data line for each bit in a byte,

while the serial I/O uses a single data line for all the bits in the data stream by

transferring the bits in sequence. The synchronous mode involves synchronizing the

data transfer with a clock while the asynchronous mode does not. PIC

microcontrollers most often have parallel I/O capability built in and the serial I/O as a

peripheral feature.

3.2.2 PIC18F4455 architecture

As shown in figure 3.3 is a typical PIC18F4455, a 40-pin high performance

nano watt technology microcontroller, was used in the actual design (Microchip,

2007).

Figure 3.3 : 40-Pin PIC18F4455 microcontroller

The features of PIC18F4455 are:

40

• 24576 Bytes flash program memory,

• Capable of 12288 instruction set,

• 2048 Bytes of Data memory,

• 256 Bytes of Data EEPROM memory,

• 18 interrupt sources,

• USB V.20 compliant,

• 100,000 erase/write cycle,

• Programmable code protection,

• Data retention of over 40 years,

• Self-programmable under software control,

• Enhanced USART module, and

• C compiler optimized architecture.

41

Figure 3.4 : PIC18F4455 block diagram

42

3.2.3 PIC18F4455 programming

Figure 3.4 is a detailed block diagram of the PIC4455. In programming it,

a complier and a programmer were used. There are many available compilers for

PIC18F4455 such as MikroC, Hi-Tech, MikroBasic, MikroPascal, CCS C and

MPLAB, but CCS C (whose interface is shown in figure 3.5) was used. Also, there

are many programmers available but MikroElectronika development board (it's

control interface is shown in figure 3.6) was used.

Figure 3.5 : CCS C compiler IDE interface

The CCS C compiler has an Integrated Development Environment (IDE)

through which programs written can be compiled into Hexadecimal codes. The IDE

interface is shown above.

43

Figure 3.6 : MikroElectronika programmer interface

3.2.4 Nokia 6021

Nokia 6021, shown in figure 3.7, is an EDGE (Enhanced Data Rates for

GSM Evolution) enabled mobile phone. It is built on the GSM technology standard

and has both Infrared and Bluetooth transceivers, these features make it suitable for

use in building an home automation system. It can serve as an extremely long range

remote (one that can be controlled from anywhere in the world) via a combination of

two or more of its Infrared or Bluetooth functionality, voice and data call capabilities,

44

short and multimedia message service (SMS/MMS) and wireless application protocol

(WAP). It also has an RS232 data cable called DKU-5 cable with which the phone can

be connected to any RS232 serial communication capable device.

Figure 3.7 : Nokia 6021 mobile phone

In remote communication with the Nokia 6021, Hayes command set (also

known as AT command) is used. This command set is a specific command language

consisting of series of short text strings which combine together to produce complete

commands for operations such as dialling, hanging up, sending/reading text messages,

and changing the parameters of the connection.

3.2.5 HIN232

HIN232, shown in figure 3.8, is an RS232 transmitter/receiver interface

chip, used for making serial communication possible between a device that uses TTL

(transistor-transistor logic) signal levels and another device that uses RS232 signal

levels (Intersil, 2008).

45

Figure 3.8 : HIN232 pinout

It requires a single +5V power supply and feature onboard charge pump

voltage converters which generate +10V and -10V supplies from the 5V supply. Its

drivers feature true TTL input compatibility, slew-rate limited output, and 300Ω

power-off source impedance. The receivers can handle up to +30V, and have a 3kΩ to

7kΩ input impedance, and they feature hysteresis to greatly improve noise rejection.

Table 3.1 : HIN232 pin descriptions

Table 3.1 gives a detailed working description of each pin.

46

3.2.6 Relay

Relay is a small electrical switch consisting of an electromagnet (coil), a

switch and a spring, that opens and closes under the control of another electrical

circuit. The spring holds the switch in one position, until a current is passed through

the coil, the coil generates a magnetic field which moves the switch. Because the relay

is able to control an output circuit of higher power than the input circuit, it is often

used to automatically switch large electrical power devices (Wikipedia, 2009).

There are many types of relay, namely;

• Latching relay – This relay has two relaxed states (bistable) and it is

often referred to as 'impulse', 'keep' or 'stay' relay. When the current is

switched off, the relay remains in its last state. This is possible due to a

solenoid operating a ratchet and cam mechanism, or by having two

opposing coils with an over-center spring or permanent magnet to hold the

armature and contacts in position while the coil is relaxed. Hence, the first

pulse of current to the coil turns the relay on and the second pulse turns it

off.

• Reed relay – This relay has a set of contacts inside a vacuum or inert

gas-filled glass tube, which protects the contacts against atmospheric

corrosion. The contacts are closed by a magnetic field generated when

current passes through a coil around the glass tube. Reed relays are capable

of faster switching speeds than most other relay types, but have a low

switch current and voltage ratings.

47

• Contactor relay – This is a very heavy-duty relay used for switching

electric motors and lighting loads. High current contacts are made with

alloys containing silver. Though there is an unavoidable arcing and the

contacts oxidize, the silver oxide formed is still a good conductor.

Contactor relays are often used for motor starters and they generate a lot of

noise when switching.

• Solid-state relay – This relay type is a solid state electronic

component that provides the same function as the electromagnetic relay. It

is just that it does not have any moving part which increases its long-term

reliability.

48

CHAPTER FOUR

DESIGN AND IMPLEMENTATION

The design of this project involved coupling several hardware components

and testing at the different stages of the implementation.

Firstly, a flow chart as shown in figure 4.1 was developed for the design

indicating the processes involved.

Figure 4.1 : Flow chart of the design

49

Phone rings

Switch appliance off

Start

Switch applianceon

Appliance already switched on

Send messageSend message

No Yes

Yes

4.1 BUILDING THE POWER SUPPLY AND INTERFACING THE RELAY

In building the power supply, as illustrated in figure 4.2 the following

components were used;

• 220/9V 500mA 50Hz transformer,

• 4700µF, 35V capacitor,

• bridge rectifier, and

• 5V voltage regulator.

Figure 4.2 : The power supply

50

Voltage regulator

Capacitor

Transformer

Bridge rectifier

The primary side of the transformer was connected to a 220V AC mains

while the 9V secondary side was connected to the alternating voltage input pins of the

bridge rectifier. The DC output of the bridge rectifier was sent to the 5V voltage

regulator which supplies the constant 5V voltage supply needed by the PIC4455 and

HIN232.

4.2 SERIAL COMMUNICATION BETWEEN THE MICROCONTROLLER

AND NOKIA 6021

In making possible the serial communication between the PIC4455

microcontroller and the Nokia 6021 mobile phone, the voltage level signals from the

RS232 DB-9 data cable of the phone had to be converted to the corresponding

TTL/CMOS voltage level signals that the microcontroller understands. In doing this,

HIN232 which is an RS232 line driver/receiver was used to convert the RS232 signals

to their corresponding TTL/CMOS signals. The microcontroller transmit pin C6 and

receive pin C7 were connected to the TTL/CMOS input and output pins 9 and 10, in

doing this connection it was necessary to connect the transmit pin (C6) of the

microcontroller to the input receive pin of the HIN232 and the receive pin (C7) of the

microcontroller to the output transmit pin of the HIN232. This ensured the cross

connection required for serial communication between two DCEs (Data

Communication Equipment) for both the microcontroller and the Nokia 6021 are

DCEs. For the DB-9 cable, the transmit pin 2 is connected to the RS232 output pin 7

and the receive pin 3 is connected to the RS232 input pin 8.

Finally, the DTR (data terminal ready) pin 4 and RTS (request to send) pin

7 of the DB-9 cable were connected to the +5V terminal while the signal ground pin 5

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was connected to the ground terminal. The complete connection is shown in figure

4.3.

Figure 4.3 : The RS232 to microcontroller portion of the design

4.3 PROGRAMMING THE MICROCONTROLLER

In programming the microcontroller, CCS C compiler was used to write the

PIC C code that was built into an hexadecimal code to be programmed into the

PIC4455.

The PIC C program code implemented for the PIC4455 microcontroller

was developed stepwise as –

• Include the required header files which are 18f4455.h and string.h

header files.

• Include the required class file which is input.c.

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HIN232

PIC4455microcontroller

RS232 DB-9 connector

• Set the communication parameters like the clock rate (20 MHz), the

baud rate (9600 bits/s), the transmit pin (PIN C6) and the receive pin

(PIN C7).

#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)

• Initialize the PIC4455 ports to be used. Pin C7 was set as an input pin

since it was the receive pin, the port D was initialized to low since D4

pin would be used to control the relay.

• Send the AT commands that will put the phone in text mode

(at+cmgf=1) and notification mode (at+cnmi=2,3,2,2,1). This was

required for the phone to notify the microcontroller of an incoming call.

printf(“at+cmgf=1;+cnmi=2,3,2,2,1\r”);

• Put the microcontroller in a waiting mode such that if it detects data on

its receive pin, it will execute the main functional codes that will

compare the incoming data with some predetermined data to determine

if the phone is ringing and the course of action to take before going

back to the waiting mode.

if(kbhit()){...}

4.4 TESTING THE COMPLETE DESIGN AND CASING

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After the completion of the hardware coupling, several tests were done on

the design. Some observations and corrections were made as follows:

1. The system would not work when the phone is connected after

powering it, even after a reset. This was due to the fact that the signals

sent at first by the system to the phone do not die of the line immediately

and affects subsequent signals sent even after connecting and resetting the

system. This can be prevented by connecting the phone first before

powering the system. Much concern was not given to this shortcoming

because the system was designed to have a permanently connected phone,

making it impossible for this shortcoming to arise.

2. It was also observed that the system would not respond after about

four loop cycles (this corresponds to four concurrent switch toggle). This

was due to buffer overflow on the microcontroller which makes it not

process new data sent it by the phone after those cycles. The attempted

solution was to find a way of flushing the buffer after each cycle, but due

to little help found from books, internet and fellow PIC programmers, it's

solution could not be implemented.

Other than in the above stated situations, the system worked very well and

reliably.

In designing the case for the system, utmost concern was given to guarding

the system from physical strain and stress during carriage and project presentation. A

transparent plastic material was used for the casing as against glass material which

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may easily break, a paper material which may give in to strain and stress, or even a

metallic material which will make the project work quite uneconomical, clumsy and

heavy. The casing was made in a manner that permits the whole circuit board to be

detached from the system.

The complete home automation system circuit controlling a lighting

fixture, and the designed system are shown in figure 4.4 and 4.5.

Figure 4.4: The complete home automation system circuit (controlling lighting fixture)

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Figure 4.5: The individual control home automation system

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CHAPTER FIVE

CONCLUSION AND RECOMMENDATION

5.1 CONCLUSION

It is evident from this project work that an individual control home

automation system can be cheaply made from low-cost locally available components

and can be used to control multifarious home appliances ranging from the security

lamps, the television to the air conditioning system and even the entire house lighting

system. And better still, the components required are so small and few that they can

be packaged into a small inconspicuous container.

The designed home automation system was tested a number of times and

certified to control different home appliances used in the lighting system, air

conditioning system, heating system, home entertainment system and many more

(this is as long as the maximum power and current rating of the appliance does not

exceed that of the used relay).

Finally, this home automation system can be also implemented over

Bluetooth, Infrared and WAP connectivity without much change to the design and yet

still be able to control a variety of home appliances. Hence, this system is scalable

and flexible.

5.2 RECOMMENDATION

In consonance with the project work and in view of the researched methods

and undertakings in the project design, the following are recommended:

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• The department should help the students in getting components that

are not locally available.

• Students should be taught how to make embedded systems as the use

of computer software in most project work makes it uneconomical, and

the use of the conventional integrated circuits and logic gates makes the

project work clumsy.

• Finally, this project can be further developed to control more than

one home appliance at once through the use of short message service texts

rather than voice dial though it will be more expensive and will require

more relay circuits, making it a distributed control home automation

system. Also, to cut the cost of mobile phone, the project may be

implemented using standalone GSM modems that only perform

specialised functions like text messaging and/or phone calls. This GSM

modems often are cheaper and more reliable than GSM mobile phones.

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REFERENCES

Byte Craft (2002). First Steps with Embedded Systems. Byte Craft Limited, Canada.

B & B Electronics (2003) RS-232 connections that work! DTE & DCE FAQ. From http://www.bb-elec.com Retrieved on 29/03/2003

Collins, T. J. (2008). A project report on the design and construction of a low voltage power line communication system. Project Report, FUTA Akure.

Intersil (2008). HIN232 datasheet. Intersil Inc, USA.

Martin Bates (2006). Interfacing PIC Microcontrollers Embedded Design by Interactive Simulation. Newnes, London.

Microchip (2007). PIC 18F2455/2550/4455/4550 Data Sheet. Microchip Technology. Inc, USA

Nigel Gardner (1998). An Introduction to programming the Microchip PIC in C. Character Press, UK.

Wikipedia (2009). Automation. From http://en.wikipedia.org/wiki/Automation. Retrieved on 7/30/2009

Wikipedia (2009). Bluetooth. From http://en.wikipedia.org/wiki/Bluetooth. Retrieved on 7/30/2009

Wikipedia (2009). Building Automation. From http://en.wikipedia.org/wiki/Building_automation. Retrieved on 7/30/2009

Wikipedia (2009). Ethernet. From http://en.wikipedia.org/wiki/Ethernet. Retrieved on 8/3/2009

Wikipedia (2009). European Home Systems Protocol. From http://en.wikipedia.org/wiki/European_Home_Systems_Protocol. Retrieved on 8/3/2009

Wikipedia (2009). GSM. From http://en.wikipedia.org/wiki/GSM. Retrieved on 8/7/2009

Wikipedia (2009). Home Automation. From http://en.wikipedia.org/wiki/Home_automation. Retrieved on 7/6/2009

Wikipedia (2009). INSTEON. From http://en.wikipedia.org/wiki/INSTEON. Retrieved on 8/3/2009

59

Wikipedia (2009). KNX (standard). From http://en.wikipedia.org/wiki/KNX_(standard). Retrieved on 8/3/2009

Wikipedia (2009). LonWorks. From http://en.wikipedia.org/wiki/LonWorks. Retrieved on 8/3/2009

Wikipedia (2009). Microcontroller. From http://en.wikipedia.org/wiki/Microcontroller. Retrieved on 8/3/2009

Wikipedia (2009). ONE.NET. From http://en.wikipedia.org/wiki/ONE.NET. Retrieved on 8/3/2009

Wikipedia (2009). RS232. From http://en.wikipedia.org/wiki/RS232. Retrieved on 7/21/2009

Wikipedia (2009). X10 (Industry Standard). From http://en.wikipedia.org/wiki/X10_(industry standard). Retrieved on 8/3/2009

Wikipedia (2009). ZigBee. From http://en.wikipedia.org/wiki/ZigBee. Retrieved on 8/3/2009

Wikipedia (2009). Z-Wave. From http://en.wikipedia.org/wiki/Z-Wave. Retrieved on 8/3/2009

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APPENDIX I: Bill of components

ITEM SYMBOL VALUE COST (N)1 B1 Bridge Rectifier 502 C1 1.0 µF 103 C2 1.0 µF 104 C3 1.0 µF 105 C4 1.0 µF 106 C5 1.0 µF 107 C6 4700 µF 108 C7 22 pF 109 C8 22 pF 1010 D1 DB-9 RS232 Cable 80011 F1 Board 10012 F2 Board 10013 H1 HIN232 7014 L1 LED 515 NI NOKIA 6021 650016 P1 PIC4455 200017 R1 10 kΩ 5

18 R2 330 Ω 519 R3 200 Ω 520 S1 6V 10A Relay 5021 T1 Transformer 30022 U1 TIP41C 5023 U2 TIP41C 5024 V1 LM7805 5025 V2 LM7806 5026 X1 Crystal Oscillator 7027 Z1 Reset Button 20

TOTAL 10360

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APPENDIX II: The PIC C code for programming the PIC4455 in CCS C

compiler

#include <18f4455.h>

#use delay(clock=12000000)#use rs232(baud=9600, xmit=PIN_C6,rcv=PIN_C7)#fuses HS,NOWRT,NOWDT,NOPUT,NOPROTECT,NOBROWNOUT,NOLVP,NOCPD,NODEBUG

#use fast_io(A)// enhances self i/o settings#use fast_io(B)#use fast_io(C)

#include <string.h>// header file#include <input.c>int i,u,a,b,counter=1,toggle;char data[20],data1[20],data2[20],data3[20],test[12],mem[12],req[12];

void main(){

set_tris_c(128);set_tris_b(0);output_b(255);set_tris_d(0);output_d(0);

delay_ms(500);printf("at+cmgf=1;+cnmi=2,3,2,2,1\r"); /* This puts the phone in text mode and enables notification sending */

i=getch(); // \u=getch(); // \gets(data); // \ // |-Extract and silent the initial sent instruction i=getch(); // /u=getch(); // /gets(data1);// /back:

if(kbhit()) //Run the subsequent codes when there is a new data{welcome:

if(counter==200) // \_ Re-initialise the countercounter=0; // /gets(data2);

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gets(data3);

b=0; for(a=1;a<=6;a++) { req[b]=data3[a]; b++; }strncpy(mem,req,4);strcpy(test,"RING"); /* The control string which the phone sends when there is a phone call */

if(strncmp(mem,test,4)==0) //check if the notification is for phone ringing{counter++; //Increment the countertoggle=counter%10;if(toggle==5){output_high(PIN_D4); //put 5V on the D4 pinprintf("at+cmgs=\"08064702218\"\r");printf("appliance is switched on");putc(26);

}if(toggle==0){output_low(PIN_D4); //set pin D4 to 0V//delay_ms(5);printf("at+cmgs=\"08064702218\"\r");//delay_ms(50);printf("appliance is switched off");putc(26);//delay_ms(10);}}

goto welcome;}

goto back;}

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