Wireless appliances control report

1. 1
A
Report
on
WIRELESS BASED CONTROL
Submitted In Partial Fulfillment Of Requirement Of The Degree
Of
BACHELOR OF TECHNOLOGY
Submitted By:
Electronics & Communication Department
The Department Of Electronics & Communication Engineering
Abc ENGINEERING TECHNOLOGY, JAIPUR December, 2011.

2. 1
Department Of Electronics & Communication Engineering
CERTIFICATE
This is to certify that a Project Report on “WIRELESS BASED CONTROLE” is submitted
by xyz students of final year 201-201 in Partial fulfillment for the award of Degree
Bachelor of Technology in Electronics & Communication Engineering, to abc
ENGINEERING & TECHONOLOGY JAIPUR is a record of the students
own work carried out under my supervision.
Guide:
Lecture HOD
Deptt. Of ECE Deptt. Of ECE

3. 1
Acknowledgment
This satisfaction that accompanies the successful completion of any task
would be incomplete without the mention of people whose ceaseless co-
operation made the task possible. Their constant guidance and
encouragement place a much important role in successful completion of that
work.
I express my gratitude to all those who helped in various stages of this
study. Most importantly I would like to thank MS. & MR for imparting his
valuable knowledge and experiences regarding the subject.
At last but not the least thankful to all the staff member of abc
ENGINEERING & TECHNOLOGY, JAIPUR, Department of Electronics and
Communication Engineering.
a
b

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Abstract
Security is a prime concern in our day-today life. Everyone wants to be as much secure as
possible. Wireless Secured Lock System is an embedded project used to operate any
solenoidal lock or any other appliances whether 220volts or 5volts.
. The microcontroller based project is an access control system that allows only
authorized persons to access appliances via code. The system is fully controlled by the 8 bit
microcontroller AT89S52 which has a 8Kbytes of ROM for the program memory. The
password is set by the user at the system startup
The system has a 4-switches keypad by which the password can be entered through
it. When the entered password equals with the password stored then the relay gets on and
so that the appliance is on. If we entered a wrong password then system doesn’t responses.

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TABLE OF CONTENTS
1. Acknowledgment……………………………………………………………………..
3
2. Abstract……………………………………………………………………………….
4
1. Introduction …………………………………………………………………….……..…
9
2. Project Description………………………………………………………………………
10
2.1 Block
diagram…………………………………………………………………...10
2.2 Block diagram
Explanation……………………………………………………..10
2.2.1 Atmel’s AT89S52 Microcontroller………………………………..…
10
1. CPU……………………………………………………………...1
2
2. Timers/Counters………………………………………………….
13
3. Description……………………………………………………….
13
4. Pin
Description…………………………………………………...14
5. Status of External
Pins…………………………………………...16
2.2.2 Keypad……………………………………………………………….
18
1. Description……………………………………………………….
19

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2.2.3 ULN 2003 IC (Relay Driver IC)
…………………………………….19
1. Description……………………………………………………….
19
2. Pin
Diagram……………………………………………………...20
3. Absolute Maximum
Ratings……………………………………..20
2.2.4 Display Section – 16x2
LCD………………………………………...20
1. General
Specification…………………………………………….21
2. Features…………………………………………………………..
22
3. Pin
Diagram……………………………………………………...22
4. Pin
Description…………………………………………………..23
5. Absolute Maximum
Ratings……………………………………..23
2.2.5 Relay…………………………………………………………………
24
1. Working…………… ……………………………………………
24
2. Types of
Relays…………………………………………………..25
2.2.6 Power
Supply………………………………………………………...26
1. Regulator IC (7805)
…………………………………………......26
3. Hardware & Software
Requirements…………………………………………………..27

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3.1 Hardware
Requirements………………………………………………………….27
3.2 Software
Requirements…………………………………………………………..27
3.2.1 Introduction To Keil…………………………………………………
28
3.3
Programmer……………………………………………………………………....29
4. Circuit Diagram
Description…………………………………………………………....30
4.1 Circuit
Diagram…………………………………………………………….........30
4.2 Circuit Diagram
Explanation……………………………………………….........32
5 Flow
Chart………………………………………………………………………………..36
5.1
Flowchart………………………………………………………………………...36
6. Source
Code……………………………………………………………………………...37
7.Soldering……………………………………………………………………………..
…...40
7.1
Procedure……………………………………………………………………
…...40
8.
Testing…………………………………………………………………………………….41
8.1 Test Plans …………………………………………………………………….
….41
8.2 Types Of Testing…………………………………………………………………
41

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9. Conclusion And Future Trends……………………………………………………...
….42
9.1
Applications……………………………………………………………………...42
9.2 Future
Enhancements……………………………………………………….........42
Bibliography………………………………………………………………………………...
43

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List of Figures-
Figure 1: Block
Diagram…………………………………………………………………….10
Figure 2: AT89S52 40 PIN
Microcontroller………………………………………………...11
Figure 3: Pin
Diagram……………………………………………………………………….14
Figure 4: Block Diagram of 8051
Microconroller…………………………………………...15
Figure 5: Oscillator
Connections…………………………………………………………….16
Figure 6: Keypad………………………………………………………………………….…
19
Figure 7: ULN 2003A IC(DIP Package)
…………………………………………………....20
Figure 8: Pin Diagram Of ULN 003 IC………………………………………………….
….20
Figure 9: A 16x2 LCD………………………………………………………………….
…...21
Figure 10:LCD Pin Diagram…………………………………………………………..……
22
Figure 11: Relay’s Working…………………………………………………………….
…..24
Figure 12: General Purpose
Relay……………………………………………………….....25
Figure 13: Power
Relay……………………………………………………………………..25
Figure 14: Solid State
Relay………………………………………………………………..25
Figure 15: 7805
IC………………………………………………………………………….26
Figure 16: Circuit Diagram…………………………………………………………………
27

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Figure 17: Flow Chart………………………………………………………………………
28
Figure 18: Encoder HT12E…………………………………………………………………
29
Figure 19: RF Transmitter Module
………………………………………………………...33
Figure 20: RF Receiver Module
…………………………………………………………...34
Figure 21: Decoder
HT12D………………………………………………………………...35

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List of Tables-
Table 1: Port 3 PinTable 1: Port 3 Pin
Functions………………………………………………………………...16Functions………………………………………………………………...16
Table 2: Status of External
Pins……………………………………………………………...18
Table 3:Max Rating Of
AT89C51…………………………………………………………...18
Table 4: Types of ULN
IC…………………………………………………………………...19
Table 5: Absolute Maximum
Ratings………………………………………………………..20
Table 6: Pin
Description…………………………………………………………………….23
Table 7: Absolute Maximum
Ratings……………………………………………………….23

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1. Introduction
Wireless: This project is using Radio Frequency of 433 MHz in Transmission and
Reception via Transmitter, Receiver and Antennas.
Secured: It is secured as it will be having Output only if the code entered satisfies the Code
written in the Microcontroller. Codes are entered through the combination of the switches
on the remote. Also the code entered is visible to us by the glowing LEDs.
Embedded Technology: An embedded system is a special-purpose system in which the
computer is completely encapsulated by the device it controls. Unlike a general-purpose
computer, such as a personal computer, an embedded system performs pre-defined tasks,
usually with very specific requirements. Since the system is dedicated to a specific task,
design engineers can optimize it, reducing the size and cost of the product. Embedded
systems are often mass-produced, so the cost savings may be multiplied by millions of
items.
The system comprises a keypad and the keypads are connected to the 4 bit encoder.
At receiver section Decoder is connected to microcontroller AT89S52. This is one of the
popular Microcontroller. It has 40 pins and there are 32 input/output lines. The
microcontroller has a program memory of 4Kilobytes. The microcontroller continuously
monitor the code and if somebody enters the password it will check the entered password
with the password which was stored in the memory and if it they are same then the
microcontroller will switch on the corresponding appliance’s relay.

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2. Project Description
2.1 Block Diagram
Figure 1: Block Diagram
2.2 Block Diagram Explanation
2.2.1 Atmel’s AT89S52 Microcontroller
8051’s Architencture
Atmel offers a broad range of microcontrollers based on the 8051 architecture ranging in
code density from 2K bytes to 128K bytes. The product line includes 8-bit microcontrollers
based on the powerful, low-power Single-Cycle AT89LP core as well as MCS-51®
industry standard socket drop-in devices and small footprint 14/16/20/28-pin derivatives,
all manufactured in advanced Flash technologies. Most members in this product line
include ISP (In-System Programming) capability, while some also support the high
4-Bit KeyPad Encoder & Transmitter
Power
Supply
Output
Receiver
&
Decoder
Micro
controller
AT89s52
Display
section
ULN 2003
(Relay
Driver) Relay

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speed (X2) mode which doubles the internal clock frequency for CPU and peripherals upon
user selection.There are also Application Specific 8051 Products with specialized functions
to serve dedicated markets:
• CAN Networking
• USB Applications
Atmel's single-cycle AT89LP devices can be used in existing 80C51-based applications
with binary-level code compatibility while substantially increasing performance by a factor
of 6 to12 times, up to 30MIPS. This exciting family brings modern features and peripherals
to the user while minimizing power consumption for low-voltage and battery-powered
applications.
Figure 2: AT89C51 40 PIN Microcontroller
The following list gives the features of the 8051 architecture:
• Compatible with MCS-51™ Products
• 8K Bytes of In-System Reprogrammable Flash Memory
– Endurance: 1,000 Write/Erase Cycles
• Fully Static Operation: 0 Hz to 24 MHz
• Three-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 32 Programmable I/O Lines

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• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Programmable Serial Channel
• Low-power Idle and Power-down Modes
Central Processing Unit
The CPU is the brain of the microcontrollers reading user's programs
and executing the expected task as per instructions stored there in. Its primary elements are
an 8 bit Arithmetic Logic Unit (ALU), Accumulator (Acc), few more 8 bit registers, B
register, Stack Pointer (SP), Program Status Word (PSW) and 16 bit registers, Program
Counter (PC) and Data Pointer Register (DPTR). The ALU (Acc) performs arithmetic and
logic functions on 8 bit input variables. Arithmetic operations include basic addition,
subtraction, multiplication and division. Logical operations are AND, OR, Exclusive OR as
well as rotate, clear, complement and etc. Apart from all the above, ALU is responsible in
conditional branching decisions, and provides a temporary place in data transfer operations
within the device. B register is mainly used in multiply and divide operations. During
execution, B register either keeps one of the two inputs and then retains a portion of the
result. For other instructions, it can be used as another general purpose register.
Timers/Counters
8051 has two 16 bit Timers/Counters capable of working in different modes.
Each consists of a `High' byte and a `Low' byte which can be accessed under software.
There is a mode control register and a control register to configure these timers/counters in
number of ways.These timers can be used to measure time intervals, determine pulse
widths or initiate events with one microsecond resolution upto a maximum of 65
millisecond (corresponding to 65, 536 counts). Use software to get longer delays. Working
as counter, they can accumulate occurrences of external events (from DC to 500KHz) with
16 bit precision.
In our project we are using 8 bit microcontroller AT89C2051, it is the advanced 8
bit microcontroller from ATMEL, which incorporates Flash Rom, and Timer etc.
Features of AT89S52
• Compatible with MCS-51™ Products

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• 8K Bytes of In-System Reprogrammable Flash Memory
– Endurance: 1,000 Write/Erase Cycles
• Fully Static Operation: 0 Hz to 24 MHz
• Three-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Programmable Serial Channel
• Low-power Idle and Power-down Modes
Description
The AT89S52 is a low-voltage, high-performance CMOS 8-bit microcomputer with
8 Kbytes of Flash Programmable and erasable read only memory (PEROM). The device
is manufactured using Atmel’s high density nonvolatile memory technology and is
compatible with theindustry Standard MCS-51Ô instruction set and pinout. By combining a
versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89S52 is a powerful
microcomputer which provides a highly flexible and cost effective solution to many
embedded control applications.
PIN Configurations

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Figure 3: Pin Diagram
Block Diagram
Figure 4: Block Diagram of 8051 Microconroller

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Pin Description Of AT89S52
1. VCC: Supply voltage.
2. GND: Ground.
3. Port 0: Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can
sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as
highimpedance inputs. Port 0 may also be configured to be the multiplexed loworder
address/data bus during accesses to external program and data memory. In this mode P0
has internal pullups. Port 0 also receives the code bytes during Flash programming, and
outputs the code bytes during program verification. External pullups are required during
program verification.
4. Port 1:Port 1 is an 8-bit bi-directional I/O port with internal pullups. The Port 1 output
buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled
high by the internal pullups and can be used as inputs. As inputs, Port 1 pins that are
externally being pulled low will source current (IIL) because of the internal pullups. Port 1
also receives the low-order address bytes during Flash programming and verification.
5. Port 2: Port 2 is an 8-bit bi-directional I/O port with internal pullups. The Port 2 output
buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled
high by the internal pullups and can be used as inputs.
As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because
of the internal pullups. Port 2 emits the high-order address byte during fetches from
external
program memory and during accesses to external data memory that use 16-bit addresses
(MOVX @ DPTR). In this application, it uses strong internal pull-ups when emitting 1s.
During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2
emits the contents of the P2 Special Function Register. Port 2 also receives the high-order
address bits and some control signals during Flash programming and verification.
6. Port 3: Port 3 is an 8-bit bi-directional I/O port with internal pullups. The Port 3 output
buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled
high by the internal pullups and can be used as inputs. As inputs, Port 3 pins that are
externally being pulled low will source current (IIL) because of the pullups. Port 3 also
serves the functions of various special features of the AT89C51 as listed below:

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Table 1: Port 3 Pin FunctionsTable 1: Port 3 Pin Functions
Port 3 also receives some control signals for Flash programming and verification.
7. RST: Reset input. A high on this pin for two machine cycles while the oscillator is
running resets the device.
8. ALE/PROG: Address Latch Enable output pulse for latching the low byte of the address
during accesses to external memory. This pin is also the program pulse input (PROG)
during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the
oscillator frequency, and may be used for external timing or clocking purposes. Note,
however, that one ALE pulse is skipped during each access to external Data Memory. If
desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit
set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is
weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in
external execution mode.
9. PSEN: Program Store Enable is the read strobe to external program memory. When the
AT89C51 is executing code from external program memory, PSEN is activated twice each
machine cycle, except that two PSEN activations are skipped during each access to external
data memory.

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10. EA/VPP: External Access Enable. EA must be strapped to GND in order to enable the
device to fetch code from external program memory locations starting at 0000H up to
FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on
reset. EA should be strapped to VCC for internal program executions. This pin also
receives the 12-volt programming enable voltage (VPP) during Flash programming, for
parts that require 12-volt VPP.
11. XTAL1: Input to the inverting oscillator amplifier and input to the internal clock operating
circuit.
12. XTAL2: Output from the inverting oscillator amplifier.
Oscillator Characteristics
XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which
can be configured for use as an on-chip oscillator.
Idle Mode
In idle mode, the CPU puts itself to sleep while all the onchip peripherals remain active.
The mode is invoked by software. The content of the on-chip RAM and all the special
functions registers remain unchanged during this mode. The idle mode can be terminated
by any enabled
Figure 5: Oscillator Connections

21. 1
Status of External Pins During Idle and Power-down Modes
Table 2: Status of External Pins
Absolute maximum Ratings of AT89S52 Microcontroller
Operating Temperature -55°C to +125°C
Storage Temperature -65°C to +150°C
Voltage on Any Pin
with Respect to Ground
-1.0V to +7.0V
Maximum Operating Voltage 6.6V
DC Output Current 15.0 mA
Table 3:Max Rating Of AT89S52
2.2.2 Keypad:
Keypad is a widely used input device with lots of application in our everyday life. From a
simple telephone to keyboard of a computer, ATM, electronic lock, etc., keypad is used to
take input from the user for further processing. In this article we are interfacing keypad
with the MCU AT89C51 and displaying the corresponding number on LCD. This module
can be further used in a number of systems to interfaced keypad with microcontroller and
other processors to get desired output. The program to interface keypad with controller is
written in C language which is very easy to understand.

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Figure 6: keypad
2.2.3 ULN 2003 IC (Relay Driver IC)
Description :
Figure 7: ULN 2003A IC(DIP Package)
The ULN2003 is high voltage, high current darlington arrays containing seven open
collector darlington pairs with common emitters. Each channel rated at 500mA and can
withstand peak currents of 600mA. Suppression diodes are included for inductive load
driving and the inputs are pinned opposite the outputs to simplify board layout. The four
versions ULN2001A, ULN2002A, ULN2003 and ULN2004A interface to all common
logic families:
These versatile devices are useful for driving a wide range of loads including solenoids,
relays DC motors, LED displays filament lamps, thermal printheads and high power
buffers. The ULN2001A/2002A/2003A and 2004A are supplied in 16 pin plastic DIP
packages with a copper leadframe to reduce thermal resistance. They are available also in
small outline package (SO-16) as ULN2001D/2002D/2003D/2004D.
Features of ULN 2003 IC
 Seven darlingtons per package

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 Output current 500ma per driver (600ma peak)
 Output voltage 50v
 Integrated suppression diodes for inductive loads
 Outputs can be paralleled for higher current
 TTL/CMOS/PMOS/DTL compatible inputs
 Inputs pinned opposite outputs tosimplify layout
Pin Diagram :
Figure 8: Pin Diagram Of ULN 003 IC
Absolute Maximum Ratings
Table 5: Absolute Maximum Ratings

24. 1
2.2.5 Relay
A relay is usually an electromechanical device that is actuated by an electrical current. The
current flowing in one circuit causes the opening or closing of another circuit. Relays are
like remote control switches and are used in many applications because of their relative
simplicity, long life, and proven high reliability. They are used in a wide variety of
applications throughout industry, such as in telephone exchanges, digital computers and
automation systems.
All relays contain a sensing unit, the electric coil, which is powered by AC or DC current.
When the applied current or voltage exceeds a threshold value, the coil activates the
armature, which operates either to close the open contacts or to open the closed contacts.
When a power is supplied to the coil, it generates a magnetic force that actuates the switch
mechanism. The magnetic force is, in effect, relaying the action from one circuit to another.
The first circuit is called the control circuit; the second is called the load circuit. A relay is
usually an electromechanical device that is actuated by an electrical current.
The current flowing in one circuit causes the opening or closing of another circuit.
Figure 11: Relay’s Working
Types of Relays
There are two basic classifications of relays:
A. Electromechanical Relay
B. Solid State Relay.

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Electromechanical relays have moving parts, whereas solid state relays have no moving
parts. Advantages of Electromechanical relays include lower cost, no heat sink is required,
multiple poles are available, and they can switch AC or DC with equal ease.
A. Electromechanical Relays
a. General Purpose Relay: The general-purpose relay is rated by the amount of
current its switch contacts can handle. Most versions of the general-purpose relay
have one to eight poles and can be single or double throw. These are found in
computers, copy machines, and other consumer electronic equipment and
appliances.
Figure 12: General Purpose Relay
b. Power Relay: The power relay is capable of handling larger power loads – 10-50
amperes or more.
They are usually single-pole or double-pole units.
Figure 13: Power Relay
c. Contactor: A special type of high power relay, it’s used mainly to control high
voltages and currents in industrial electrical applications. Because of these high
power requirements, contactors always have double-make contacts.
d. Time-Delay Relay: The contacts might not open or close until some time interval
after the coil has been energized. This is called delay-on-operate. Delay-on-release

26. 1
means that the contacts will remain in their actuated position until some interval
after the power has been removed from the coil.
A third delay is called interval timing. Contacts revert to their alternate position at a
specific interval of time after the coil has been energized.
The timing of these actions may be a fixed parameter of the relay, or adjusted by a
knob on the relay itself, or remotely adjusted through an external circuit.
B.Solid State Relays
Figure 14: Solid State Relay
These active semiconductor devices use light instead of magnetism to actuate a switch. The
light comes from an LED, or light emitting diode. When control power is applied to the
device’s output, the light is turned on and shines across an open space. On the load side of
this space, a part of the device senses the presence of the light, and triggers a solid state
switch that either opens or closes the circuit under control.
2.2.6 Power Supply
1. Regulator IC (7805)
The LM7805 monolithic 3-terminal positive voltage regulators employ internal
current-limiting, thermal shutdown and safe-area compensation, making them essentially
indestructible. If adequate heat sinking is provided, they can deliver over 1.0A output
current. They are intended as fixed voltage regulators in a wide range of applications
including local (on-card) regulation for elimination of noise and distribution problems

27. 1
associated with single-point regulation. In addition to use as fixed voltage regulators, these
devices can be used with external components to obtain adjustable output voltages and
currents. Considerable effort was expended to make the entire series of regulators easy to
use and minimize the number of external components. It is not necessary to bypass the
output, although this does improve transient response. Input bypassing is needed only if the
regulator is located far from the filter capacitor of the power supply.
Features:
 Complete specifications at 1A load
 Output voltage tolerances of ±2% at Tj = 25°
 Line regulation of 0.01% of Vout/V of Vin at 1A load
 Load regulation of 0.3% of Vout/A
 Internal thermal overload protection
 Internal short-circuit current limit
 Output transistor safe area protection
Figure 15:7805 IC

28. 1
3. Hardware & Software Requirements
3.1 Hardware Requirements
This system describes the various hardware’s that are included in the Automatic
Plant Irrigator are as follows:
Components List
IC AT89S52 : It is a 40-pin, Microcontroller chip produced by Atmel
IC 7805 : It is a 3 terminal, 5V positive voltage regulator.
ULN2003 : It is a Buffer IC used to drive the relay
Relay : 12V, 1A relay. It is an electro-mechanical switch.
Diodes : 1N4001, required for protection of relay
Crystal : 12 MHz, for clock signal generation.
Resistors : Various ranges of carbon resistors are required
Capacitors : Various ranges of capacitors are required
LCD : For Display purpose.
PCB : The system uses a single sided PCB to which all components are
soldered.
3.2 Software Requirements
3.2.1 Introduction To Keil
Keil MicroVision is an integrated development environment used to create software
to be run on embedded systems (like a microcontroller). It allows for such software to be
written either in assembly or C programming languages and for that software to be
simulated on a computer before being loaded onto the microcontroller.
μVision3 is an IDE (Integrated Development Environment) that helps write,
compile, and debug embedded programs. It encapsulates the following components:
• A project manager.
• A make facility.
• Tool configuration.
• Editor.
• A powerful debugger.
To create a new project in uVision3:

29. 1
1. Select Project - New Project.
2. Select a directory and enter the name of the project file.
3. Select Project –Select Device and select a device from Device Database.
4. Create source files to add to the project
5. Select Project - Targets, Groups, and Files. Add/Files, select Source Group1, and
add the source files to the project.
6. Select Project - Options and set the tool options. Note that when the target device is
selected from the Device Database all-special options are set automatically. Default
memory model settings are optimal for most applications.
7. Select Project - Rebuild all target files or Build target.
3.3 Programmer
The programmer used is a powerful programmer for the Atmel 89 series of
microcontrollers that includes 89C51/52/55, 89S51/52/55 and many more.
It is simple to use & low cost, yet powerful flash microcontroller programmer for
the Atmel 89 series. It will Program, Read and Verify Code Data, Write Lock Bits, Erase
and Blank Check. All fuse and lock bits are programmable. This programmer has
intelligent onboard firmware and connects to the serial port. It can be used with any type of
computer and requires no special hardware. All that is needed is a USB port which all
computers have.
All devices also have a number of lock bits to provide various levels of software
and programming protection. These lock bits are fully programmable using this
programmer. Lock bits are useful to protect the program to be read back from
microcontroller only allowing erase to reprogram the microcontroller.
Major parts of this programmer are USB Port, Power Supply and Firmware
microcontroller. Data is sent and received from USB connector. A Male USB port cable, is
connected to the USB port of computer. All the programming ‘intelligence’ is built into the
programmer so you do not need any special hardware to run it. Programmer comes with
window based software for easy programming of the devices.

30. 1
4. Circuit Diagram Description
4.1 Circuit Diagram
]
Power Supply
SUPPLY
RF TX SECTION RF RX SECTION
12 volt
5 volt

31. 1
CONTROLLER SECTION

32. 1
4.2. Circuit Diagram Explanation
4-bit Keypad can be kept at a distance of 100 meters (standard condition) from the
Receiver. It works with the supply of 9 volts.Used for taking in the Code by User and
transmitting the code to the Receiver Board.It Comprises of Switches, Resistor, LEDs,
Encoder and Transmitter. The Code pattern is entered through the switche’s On-Off
sequence.
The code is Encoded and Transmitted via RF Transmitter.
ENCODER HT12E:
The encoders are a series of CMOS LSIs for remote control system applications. They are
capable of encoding information which consists of N address bits and 12-N data bits. Each
address/
data input can be set to one of the two logic states. The programmed addresses/data are
transmitted together with the header bits via an RF or an infrared transmission medium
upon receipt of a trigger signal.
Features
* Operating voltage
* 2.4V~5V for the HT12A
* Low power and high noise immunity
CMOS technology
* Low standby current: 0.1*A (typ.) at VDD=5V
* Minimum transmission word Figure 18: Encoder HT12E
* Four words for the HT12E
* Built-in oscillator needs only 5% resistor
* Data code has positive polarity
* Minimal external components
RF TRANSMITTER MODULE:
These modules are now widely and
cheaply available with the operating
frequency of 433 MHz.
The transmitter module accepts serial

33. 1
data. The encoder IC takes in parallel data at the TX side packages it into serial format and
then transmits it with the help of a RF transmitter module.
Features
Range in open space (Standard Conditions): 100 Meters
Low Power Consumption
Easy For Application
TX Frequency Range: 433.92 MHz
TX Supply Voltage: 3V ~ 6V
433 MHz Transmitter:
The TX433 wireless RF transmitter uses on/off keying to transmit data to the matching
receiver, RX433. The data input “keys” the saw resonator in the transmitter when the input
is +3 volts or greater, AM modulating the data onto the 433 MHz carrier. The data is then
demodulated by the receiver, which accurately reproduces the original data. The data input
is CMOS level Compatible when the unit is run on +5 volts.
When driving with a CMOS input, there must be enough level to achieve at least 3V on the
data input, 5V is preferable. This is due to the start-up time of the oscillator needing to be
fast to accurately reproduce your data. If the voltage is too low, the oscillator will not start
fast enough to accurately reproduces your data, especially at higher data rates. Luckily not
much drive is needed, so this should be easy since it is 22K ohms of load. Almost any
CMOS output will drive this without any problems. There are some CMOS outputs which
have very little drive capability which may not work, so testing the voltage at the data input
may be a wise choice if you are having problems.
ANTENNA CONSIDERATIONS:
The simplest antenna consists of a piece of wire approximately 6 to 7 inches long. If you
desire more range you can try a ground plane antenna or a Yagi such as the Ramsey 400-4
model. The antenna should be tuned for the 433 MHz band for best operation.
Having two Yagi antennas, one for the transmitter and one for the receiver will allow you
to extend the range considerably, but since they are directional, this would be best for if
your receiver and transmitter are in fixed positions.

34. 1
Receiver Board:
Receiver Board receives the transmitted serial code by the transmitter’s antenna. It have a
Receiver Antenna. The Code received is applied to the Decoder IC. It converts the serial
data to the parallel data(code). The received code pattern is seen on the LED pattern. The
same code is applied to the Microcontroller’s Port 1 (Pin 5 to Pin 8).
The Micro-controller compares the code with the security code and gives output to the Port
2 ( Pin 21).
The output of at Pin 21 is small and not enough for the working of the Relay. For
amplifying ULN2003 IC is used. The boosted output is then apllied to the Relay.
Receiver Board Parts Description:
RF RECEIVER MODULE:
These modules are now widely and cheaply available with the operating frequency of 433
MHz. At the RX end, the decoder IC receives the signal via the RF receiver module,
decodes the serial data and reproduces the original data in the parallel format.
Features
Range in open space:
(Standard Conditions) 100 Meters
RX Receiver Frequency: 433 MHz
Low Power Consumption
Easy For Application
RX Operating Voltage: 5V
433 MHz RF Receiver Figure 20: RF Receiver
Module
The receiver shown in Figure also contains just one transistor. It is biased to act as a
regenerative oscillator, in which the received antenna signal causes the transistor to switch
to high amplification, thereby automatically arranging the signal detection. Next, the ‘raw’
demodulated signal is amplified and shaped-up by op-amps. The result is a fairly clean

35. 1
digital signal at the output of the receiver. The logic high level is at about 2/3 of the supply
voltage, i.e., between 3 V and 4.5 V.
The range of the simple system shown in Figures is much smaller than that of more
expensive units, mainly because of the low transmit power (approx. 1 mW) and the relative
insensitivity and wide-band nature of the receiver. Moreover, amplitude-modulated noise is
not suppressed in any way.
DECODER HT12D:
The decoders are a series of CMOS LSIs for remote control system applications. They are
paired. For proper operation, a pair of
Encoder/ decoder with the same number of addresses and data format should be chosen.
The decoders receive serial addresses and data from programmed encoders that are
transmitted by a carrier using an RF or an IR transmission medium. They compare the
serial input data three times continuously with their local addresses. If no error or
unmatched codes are found, the input data codes are decoded and then transferred to the
output pins. The VT pin also goes high to indicate a valid transmission. The decoders are
capable of decoding information that consists of N bits of address and 12-N bits of data.
The HT12D is arranged to provide 8 address bits and 4 data bits.
Features:
* Operating voltage: 2.4V~12V
* Low power and high noise
immunity CMOS technology
* Low standby current
* Capable of decoding 12 bits of
information
* Binary address setting
* Received codes are checked 3 times
* Address/Data number combination
* HT12D: 8 address bits and 4 data bits
* Built-in oscillator needs only 5% resistor Figure 21: Decoder HT12D
* Valid transmission indicator
* Easy interface with an RF or an infrared

36. 1
transmission medium

37. 1
5 Flow Chart
5.1 Flowchart
CORRECT
WRONG
PASSWORD ATTEMPT
Figure 22: Flow Chart
No
Acces
s
READ
KEYPAD
STAR
T
OUTPUT
HIGH
CHECK IF
WRONG
PASSWORD
ENTERED
CHECK
THE
PASSWORD

38. 1
6. Source Code
#include<reg52.h>
sbit a=P2^0;
sbit b=P2^1;
sbit c=P2^2;
sbit d=P2^3;
sbit a1=P0^0;
sbit b1=P0^1;
sbit c1=P0^2;
sbit d1=P0^3;
void main()
{ P0=P2=0x00;
while(1)
{if(a==1 && b==0 && c==1 && d==0) //1010
{a1=1;b1=0;c1=0;d1=0;}
else if(a==1 && b==0 && c==0 && d==1)//1001
{a1=0;b1=1;c1=0;d1=0;}
else if(a==1 && b==0 && c==1 && d==1)//1011
{a1=0;b1=0;c1=1;d1=0;}
else if(a==1 && b==1 && c==0 && d==0)//1100
{a1=0;b1=0;c1=0;d1=1;}
else
{a1=0;b1=0;c1=0;d1=0;}
}
}

39. 1
7. Soldering
Soldering is the process of joining metals by using lower melting point metal to wet
or alloy with the joined surfaces. Solder is the joining material. It melts below 427’C.
Soldered joints in electronic circuits will establish strong electrical connections between
component leads. The popularly used solders are alloys of tin and lead that melt below the
melting point of tin.
In order to make the surfaces accept the solder readily, the component terminals
should be cleaned chemically or by abrasion using blades or knives. Small amount of lead
coating can be done on the cleaned portion of the leads using soldering iron. This process is
called tinning. Zinc chloride or ammonium chloride separately or in combination are the
most commonly used fluxes. These are available in petroleum jelly as paste flux. A solder
joint can at first glance to be okay, but under close examination it could be a ‘Dry Joint’. A
dry joint is when either the circuit board or the leg of the component has not been properly
heated to allow the solder to flow between the surfaces freely. This creates an intermittent
or no electrical connection. This can also be caused by a lack of flux or if you reuse old
solder.
Quite often, reheating a bad join will cure the problem but in a lot of cases, the old
solder will need to be removed and some new solder applied. The residues, which remain
after the soldering, may be washed out with more water, accompanied by brushing.
Soldering iron is the tool used to melt the solder and apply at the joints in the
circuit. It operates in 230V mains supply. The iron bit at the tip of it gets heated up within a
few minutes. 50W and 25W soldering irons are commonly used for soldering purposes.
7.1 Procedure
1. Make a layout of the circuit.
2. Straighten and clean the component leads using blade or knife. Apply a little flux on
the leads. Take a little solder on soldering iron and apply the molten solder on the
leads.
3. Mount the components on the PCB by bending the leads of the components using
nose-pliers.
4. Apply flux on the joints and solder the joints. Soldering must be done in minimum
time to avoid dry soldering and heating up of components.

40. 1
8. Testing
Testing goes side by side with implementation that is aimed at ensuring that system
works accurately and effectively before the live operation is performed. The common view
of testing held by the user is to ensure that there are no errors in a program with explicit
intention of handling errors.
8.1 Test Plans
The project is made up of several interrelated modules. Unit testing was performed
at the initial stage of development in the order to fix the bugs at initial stages followed by
system testing .Here each testing was conducted on particular set of test data. At the end
acceptance testing is done to satisfy the user.
8.2 Types Of Testing
Some important types of testing are as follows.
• UNIT TESTING
• INTERGATED TESTING
• SYSTEM TESTING
• ACCEPTANCE TESTING
In testing application we tested the system. The whole application is made of
different modules and each module is made of several sub modules. Unit testing focuses on
each sub module independent of one another, to locate errors. This enables us to detect
errors that exist within that module alone.
8.3. Relationship Of Levels Of Testing
The basic levels of testing such as Unit testing, System testing, Acceptance testing had
been completed and various faults, at various steps were removed.

41. 1
9.Conclusion And Future Trends
9.1 Applications
Our electronic door lock performed as expected. We were able to implement all
of the functions specified in our proposal. The biggest hurdle we had to overcome with
this project was interfacing the micro controller with the hardware components. We
feel that this electronic door lock is very marketable because it is easy to use,
comparatively inexpensive due to low power consumption, and highly reliable. This
door lock is therefore particularly useful in applications such as hotel room door locks,
residential housing, and even office buildings.
Few applications are :
• Basically this project is use as a security purpose. We are using here this project for
providing the security to our home, similarly we can use this project to protect any
restricted area like power plant security, Border security etc.
• Project can be used to operate any device automatically, in this application entering
the correct passwoed is used to operate the device.
• It can be used for military purpose.
9.2 Future Enhancements
 Electrical devices such us Lights, Computer etc can be controlled by using
separate passwords.
 The system can be easily connected to the personal computer for further control.

42. 1
Bibliography
THE 8051 MICROCONTROLLER AND EMBEDDED SYSTEMS
-MUHAMMAD ALI MAZIDI
LINEAR INTEGRATED CIRCUITS
-R. GAYKWAD
1. The 8051Microcontroller by Kenneth J. Ayala
2. The 8051 Microcontroller and Embedded Systems by Muhammad Ali Mazidi.
3. www.8051projects.net
4. www.8051projects.info
5. www.edaboard.com
6. www.atmel.com
7. www.alldatasheets.com
8. www.electrotech.com
9. www.developershome.com
10. www.scribd.com
11. www.wikipedia.com
12. www.atmel.com