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6.2 Pin description

6.3 LCD basic commands

CHAPTER 7 :SCHEMATIC DIAGRAM

7.1 Schematic Description

7.2 regulated power supply

7.3 circuit features

CHAPTER 8 : SOFTWARE DEVELOPMENT

8.1 Introduction8.2 Tools used

8.3 C51 Compiler & A51 macro assembler

8.4 Start vision

8.5 over view of Keil cross compiler

8.6 Benefits of Keil compiler

8.7 Flash magic

CHAPTER 9 : SOURCE CODECONCLUSION

FUTURE SCOPE

REFERENCES

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LIST OF FIGURES

Figure No. NAME Page No.

1.1 Block diagram 3

1.2 Flow chart 4

1.3 Micro Controller 6

1.4 ATMEL 89S52 7

1.5 Pin diagram of ATMEL 89s52 8

1.6 Functional block diagram of Micro Controller 12

1.7 Oscillator and timing circuit 13

1.8 Ultrasonic Sensor 19

1.9 Ultrasonic Transmitter 21

1.10 Ultrasonic Receiver 22

1.11 D.C Motor 24

1.12 2-pole D.C electric motor 25

1.13 3-pole D.C electric motor 261.14 3-pole D.C electric motor 27

1.15 2x16 Line Alphanumeric LCD Display 28

1.16 Interfacing of LCD 30

1.17 Schematic Diagram 31

1.18 IC Regulator 33

1.19 Circuit diagram of power supply 33

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Table NO. Name

2.1Description of port 1

2.2Description of port 2

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ABSTRACT

KEEP DISTANCE WARNING SYSTEM

Theproject work keep distance warning system and speed control is designed for

Automobiles, any vehicle ranging from motor cycle to heavy duty truck can adopt this

system. The main purpose of this system is to alert the following vehicle whenever it came

very close to the ahead vehicle; thereby to some extent accidents can be avoided. Many

accidents at High-ways are taking place due to the close running of vehicles, all of sudden,

if the in front vehicle driver reduces the speed or applied breaks, then it is quite difficult to

the following vehicle driver to control his vehicle, resulting accident. To avoid this kind of

accident, the warning system, which contains alarm and display system can arrange at rear

side of each and every vehicle.Whenever the following vehicle came near to the in frontvehicle, immediately the display board will be energized and it shows KEEP

DISTANCE. At the same time motor speed will also be energized, the motor and display

board both remains in energized condition up to some time depending up on the program

prepared for microcontroller. For sensing the following vehicle, two ultrasonic sensors are

used; these sensors are arranged side by side, from one sensor ultrasonic signal is delivered,

this signal is transmitted in one line, whenever the following vehicle came close to the

signal, the ultrasonic energy hits the vehicle and it is reflected, the reflected energy is

detected by the another ultrasonic sensor, this is called as ultrasonic signal detector.

SOFTWARE REQUIREMENT:

1. KEIL MICRO VISION-3

2. MICRO FLASH

3. ORCAD

HARDWARE REQUIREMENT:

1. MICROCONTROLLER (89S52)

2. LM324.

3. ULTRASONIC SENSOR

4. LCD DISPLAY

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CHAPTER 1

INTRODUCTION.

1.1 Motivation

Most of the accidents in high-ways are happening due to the drowsiness of drivers,

most often this symptom is found in long distance truck drivers, these drivers may take

some time to recognize the opposite vehicle, which is running at low speed, resulting

accident. This kind of accidents may happen due to the drunken drivers also. So to increase

safety an electronic warning system is essential to alert the drivers. This kind of system can

be installed in all types of vehicles, especially in commercial vehicles, so that accident rate

can be minimized. The warning system designed here can be called as driver attention

system, which raises an alarm and energizes the display board automatically when the

following vehicle came near to the in-front running vehicle The system is designed with

89C51 microcontroller, the task is quite simple, the following vehicle detection circuit is

designed with infrared sensors, when the IR signal is interrupted due to the following

vehicle, the circuit generates high signal and it is fed to microcontroller. The detailed

description is provided in the following chapters. Nowadays with the advancement of

technology particularly in the field of micro-controllers, all the activities in our day-to-day

living have become part of information technology and we find controllers in each and

every application. Thus, the trend is directing towards micro-controller based project

works.A micro-controller contains a CPU, clock circuitry, ROM, Ram and I/O circuitry on

a single integrated circuit package. The Micro-controller is therefore, a self-contained

device, which does not require a host of associated support chips for its operation as

conventional microprocessors do. It offers several advantages over conventional multi-

chip systems.There is a cost and space advantage as extra chip costs and printed circuit

board and connectors required to support multi-chip systems are eliminated. The other

advantages include cheaper maintenance, decreased hardware design effort and decreased

board density, which is relevant in portable control equipment.

Low cost high volume products requiring a relatively simple and cheap computer

controller have traditionally characterized micro-controllers. The design optimization

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parameters require careful consideration of architectural tradeoffs, memory design factors,

instruction size, memory addressing techniques and other design constraints with respect to

area and performance. Micro-controllers functionality, however, has been tremendously

increased in the recent years. Today, one gets micro-controllers, which are stand alone for

applications in data acquisition system and control. With the help of analog-to-digital

converts, provided at the input of micro-controller, enables them direct use in

instrumentation. Another type of micro-controller has on-chip communication controller,

which is designed for applications requiring local intelligence at remote nodes and

communication capability among these distributed nodes. Advanced versions of the micro-

controller in 16-bit configuration have been introduced for high performance requirements

particularly in applications where good arithmetical capabilities are required. In this project

work ATMEL 89C51 micro-controller is used, this is 8-bit micro-controller.

1.2 Thesis organization

In view of the proposed thesis work, explanation of theoretical aspects and

algorithms used in this work are presented as per the sequence described below.

Chapter 1 describes about motivation, block diagram and flow chart.

Chapter 2 discusses about at89s52 features and its pin description.

Chapter 3 explains about the ultrasonic sensor and its features.Chapter 4 describes about D.C motor and its types.

Chapter 5 goes with L.C.D display and its pin description.

Chapter 6 explains about schematic diagram and power supply.

Chapter 7 describes about software development.

Chapter 8 deals with the source code of the project.

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1.2 BLOCK DIAGRAM

8

AT 89S52

MICRO

-CONTROLLER

LCD DISPLAY

POWER

SUPPLY

ULTRASONICSENSOR

DC MOTOR

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1.3 FLOW CHART

9

Object detection is displayed on LCD

START

Initialization of Microcontroller

Initialization of LCD

Initialization of ultrasonic

STOP

STOP

If objectis

detected

Yes

ssss

ssss

ssssssss

ssss

ssssssss

SS

SSSS

SS

SSSS

SSSSSS

SsS

NO

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CHAPTER-2

MICROCONTROLLER

2.1 A Brief History of 8051

In 1981, Intel Corporation introduced an 8 bit microcontroller called 8051. This

microcontroller had 128 bytes of RAM, 4K bytes of chip ROM, two timers, one serial port,

and four ports all on a single chip. At the time it was also referred as A SYSTEM ON A

CHIP.The 8051 is an 8-bit processor meaning that the CPU can work only on 8 bits data

at a time. Data larger than 8 bits has to be broken into 8 bits pieces to be processed by the

CPU. The 8051 has a total of four I\O ports each 8 bit wide.There are many versions of

8051 with different speeds and amount of on-chip ROM and they are all compatible with

the original 8051. This means that if you write a program for one it will run on any of

them.The 8051 is an original member of the 8051 family. There are two other members in

the 8051 family of microcontrollers. They are 8052 and 8031. All the three

microcontrollers will have the same internal architecture, but they differ in the following

aspects.

89S51 has 4KB ROM, 128 bytes of RAM, two timers and 6 interrupts.

8031 has 128 bytes of RAM, two timers and 6 interrupts.

89S52 has 8KB ROM, 128 bytes of RAM, three timers and 8 interrupts.

In the concerned project 89C52 microcontroller is used. Here microcontroller used

is AT89C52, which is manufactured by ATMEL laboratories.

2.2 Introduction to AT89S52

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller

with 8K bytes of in-system programmable Flash memory. The device is manufactured

using Atmels high-density nonvolatile memory technology and is compatible with theindustry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program

memory to be reprogrammed in-system or by a conventional nonvolatile memory

programmer.

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Figure 2.1 MICROCONTROLLER

By combining a versatile 8-bit CPU with in-system programmable Flash on a

monolithic chip, the Atmel AT89S52 is a powerful microcontroller, which provides a

highly flexible and cost-effective solution to many, embedded control applications. The

AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM,

32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector

two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock

circuitry.In addition, the AT89S52 is designed with static logic for operation down to zero

frequency and supports two software selectable power saving modes. The Idle Mode stops

the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to

continue functioning. The Power-down mode saves the RAM con-tents but freezes the

oscillator, disabling all other chip functions until the next interrupt

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Fig: ATMEL 89S52

8031 has 128 bytes of RAM, two timers and 6 interrupts.

8051 has 4K ROM, 128 bytes of RAM, two timers and 6 interrupts.

8052 has 8K ROM, 256 bytes of RAM, three timers and 8 interrupts.

Of the three microcontrollers, 8051 is the most preferable. Microcontroller supports

both serial and parallel communication.In the concerned project 8052 microcontroller is

used. Here microcontroller used is AT89S52, which is manufactured by ATMEL

laboratories.

2.3 FEATURES OF 89S52

Compatible with MCS-51 Products

8K Bytes of In-System Reprogrammable Flash Memory

Fully Static Operation: 0 Hz to 33 MHz

Three-level Program Memory Lock

256 x 8-bit Internal RAM

32 Programmable I/O Lines

Three 16-bit Timer/Counters

Eight Interrupt Sources

Programmable Serial Channel

Low-power Idle and Power-down Modes

4.0V to 5.5V Operating Range

Full Duplex UART Serial Channel

Interrupt Recovery from Power-down Mode

Watchdog Timer

Dual Data Pointer

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Power-off Flag

2.4 PIN DESCRIPTION

Figure 2.3: PIN DIAGRAM OF AT89S52 IC

Port 0

Port 0 is an 8-bit open drain bidirectional 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 can 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 duringprogram verification.

Port 1

Port 1 is an 8-bit bidirectional 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

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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. In

addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input

(P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as shown in the

following table. Port 1 also receives the low-order address bytes during Flash programming

and verification.

Table 2.1:Description of port 1

Port 2

Port 2 is an 8-bit bidirectional 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, Port 2 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.

Port 3

Port 3 is an 8-bit bidirectional 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

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serves the functions of various special features of the AT89S52, as shown in the following

table. Port 3 also receives some control signals for Flash programming and verification.

Table 2.2: Description of port 3

RST

Reset input. A high on this pin for two machine cycles while the oscillator is

running resets the device. This pin drives High for 96 oscillator periods after the Watchdog

times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this

feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled.

ALE/PROG Address Latch Enable (ALE) is an 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.

PSEN

Program Store Enable (PSEN) is the read strobe to external program memory.

When the AT89S52 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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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.

XTAL1

Input to the inverting oscillator amplifier and input to the internal clock operating

circuit.

XTAL2

Output from the inverting oscillator amplifier.

Figure 2.4: Functional block diagram of micro controller

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The 8052 Oscillator and Clock

The heart of the 8051 circuitry that generates the clock pulses by which all the

internal all internal operations are synchronized. Pins XTAL1 And XTAL2 is provided for

connecting a resonant network to form an oscillator. Typically a quartz crystal and

capacitors are employed. The crystal frequency is the basic internal clock frequency of the

microcontroller. The manufacturers make 8051 designs that run at specific minimum and

maximum frequencies typically 1 to 16 MHz.

Figure 2.5: Oscillator and timing circuit

2.5 MEMORIES

Types of memory

The 8052 have three general types of memory. They are on-chip memory, external

Code memory and external Ram. On-Chip memory refers to physically existing memory

on the micro controller itself. External code memory is the code memory that resides off

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chip. This is often in the form of an external EPROM. External RAM is the Ram that

resides off chip. This often is in the form of standard static RAM or flash RAM.

a) Code memory

Code memory is the memory that holds the actual 8052 programs that is to be run.

This memory is limited to 64K. Code memory may be found on-chip or off-chip. It is

possible to have 8K of code memory on-chip and 60K off chip memory simultaneously. If

only off-chip memory is available then there can be 64K of off chip ROM. This is

controlled by pin provided as EA

b) Internal RAM

The 8052 have a bank of 256 bytes of internal RAM. The internal RAM is found

on-chip. So it is the fastest Ram available. And also it is most flexible in terms of reading

and writing. Internal Ram is volatile, so when 8051 is reset, this memory is cleared. 256

bytes of internal memory are subdivided. The first 32 bytes are divided into 4 register

banks. Each bank contains 8 registers. Internal RAM also contains 256 bits, which are

addressed from 20h to 2Fh. These bits are bit addressed i.e. each individual bit of a byte

can be addressed by the user. They are numbered 00h to FFh. The user may make use of

these variables with commands such as SETB and CLR.

Special Function registered memory:

Special function registers are the areas of memory that control specific

functionality of the 8052 micro controller.

a) Accumulator (0E0h)

As its name suggests, it is used to accumulate the results of large no of instructions.

It can hold 8 bit values.

b) B registers (0F0h)

The B register is very similar to accumulator. It may hold 8-bit value. The b register

is only used by MUL AB and DIV AB instructions. In MUL AB the higher byte of the

product gets stored in B register. In div AB the quotient gets stored in B with the remainder

in A.

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c) Stack pointer (81h)

The stack pointer holds 8-bit value. This is used to indicate where next value to be

removed from the stack should be taken from. When a value is to be pushed onto the stack,

the 8052 first store the value of SP and then store the value at the resulting memory

location. When a value is to be popped from the stack, the 8052 returns the value from the

memory location indicated by SP and then decrements the value of SP.

d) Data pointer

The SFRs DPL and DPH work together work together to represent a 16-bit value

called the data pointer. The data pointer is used in operations regarding external RAM and

some instructions code memory. It is a 16-bit SFR and also an addressable SFR.

e) Program counter

The program counter is a 16 bit register, which contains the 2 byte address, which

tells the 8052 where the next instruction to execute to be found in memory. When the 8052

is initialized PC starts at 0000h. And is incremented each time an instruction is executes. It

is not addressable SFR.

f) PCON (power control, 87h)

The power control SFR is used to control the 8051s power control modes. Certain

operation modes of the 8051 allow the 8051 to go into a type of sleep mode which

consumes much lee power.

g) TCON (timer control, 88h)

The timer control SFR is used to configure and modify the way in which the 8051s

two timers operate. This SFR controls whether each of the two timers is running or stopped

and contains a flag to indicate that each timer has overflowed. Additionally, some non-

timer related bits are located in TCON SFR.

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h) TMOD (Timer Mode, 89h)

The timer mode SFR is used to configure the mode of operation of each of the two

timers. Using this SFR your program may configure each timer to be a 16-bit timer, or 13

bit timer, 8-bit auto reload timer, or two separate timers. Additionally you may configure

the timers to only count when an external pin is activated or to count events that are

indicated on an external pin.

i) TO (Timer 0 low/high, address 8A/8C h)

These two SFRs taken together represent timer 0. Their exact behavior depends on

how the timer is configured in the TMOD SFR; however, these timers always count up.

What is configurable is how and when they increment in value.

j) T1 (Timer 1 Low/High, address 8B/ 8D h)

These two SFRs, taken together, represent timer 1. Their exact behavior depends on

how the timer is configured in the TMOD SFR; however, these timers always count up..

k) P0 (Port 0, address 90h, bit addressable)

This is port 0 latch. Each bit of this SFR corresponds to one of the pins on a micro

controller. Any data to be outputted to port 0 is first written on P0 register. For e.g., bit 0 of

port 0 is pin P0.0, bit 7 is pin p0.7. Writing a value of 1 to a bit of this SFR will send a high

level on the corresponding I/O pin whereas a value of 0 will bring it to low level.

l) P1 (port 1, address 90h, bit addressable)

This is port latch1. Each bit of this SFR corresponds to one of the pins on a micro

controller. Any data to be outputted to port 0 is first written on P0 register. For e.g., bit 0 of

port 0 is pin P1.0, bit 7 is pin P1.7. Writing a value of 1 to a bit of this SFR will send a high

level on the corresponding I/O pin whereas a value of 0 will bring it to low level.

m) P2 (port 2, address 0A0h, bit addressable)

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This is a port latch2. Each bit of this SFR corresponds to one of the pins on a

micro controller. Any data to be outputted to port 0 is first written on P0 register. For e.g.,

bit 0 of port 0 is pin P2.0, bit 7 is pin P2.7. Writing a value of 1 to a bit of this SFR will

send a high level on the corresponding I/O pin whereas a value of 0 will bring it to low

level.

n) P3 (port 3, address B0h, bit addressable)

This is a port latch3. Each bit of this SFR corresponds to one of the pins on a micro

controller. Any data to be outputted to port 0 is first written on P0 register. For e.g., bit 0 of

port 0 is pin P3.0, bit 7 is pin P3.7. Writing a value of 1 to a bit of this SFR will send a high

level on the corresponding I/O pin whereas a value of 0 will bring it to low level.

o) IE (interrupt enable, 0A8h)

The Interrupt Enable SFR is used to enable and disable specific interrupts. The low

7 bits of the SFR are used to enable/disable the specific interrupts, where the MSB bit is

used to enable or disable all the interrupts. Thus, if the high bit of IE is 0 all interrupts are

disabled regardless of whether an individual interrupt is enabled by setting a lower bit.

p) IP (Interrupt Priority, 0B8h)

The interrupt priority SFR is used to specify the relative priority of each interrupt.

On 8051, an interrupt maybe either low or high priority. An interrupt may interrupt

interrupts. For e.g., if we configure all interrupts as low priority other than serial interrupt.

The serial interrupt always interrupts the system, even if another interrupt is currently

executing.

q) PSW (Program Status Word, 0D0h)

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The program Status Word is used to store a number of important bits that are set

and cleared by 8052 instructions. The PSW SFR contains the carry flag, the auxiliary carry

flag, the parity flag and the overflow flag. Additionally, it also contains the register bank

select flags, which are used to select, which of the R register banks currently in use.

r) SBUF (Serial Buffer, 99h)

SBUF is used to hold data in serial communication. It is physically two registers.

One is writing only and is used to hold data to be transmitted out of 8052 via TXD. The

other is read only and holds received data from external sources via RXD. Both mutually

exclusive registers use address 99h.

CHAPTER-3

Ultrasonic sensor

3.1 INTRODUCTION

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Parallax's PING ultrasonic sensor provides a very low-cost and easy method of

distance measurement. This sensor is perfect for any number of applications that require

you to perform measurements between moving or stationary objects. Naturally, robotics

applications are very popular but you'll also find this product to be useful in security

systems or as an infrared replacement if so desired. You will definitely appreciate the

activity status LED and the economic use of just 1 I/O pin.

Figure 3.1: Ultrasonic Sensor

The Ping sensor measures distance using sonar; an ultrasonic (well above human

hearing)pulse is transmitted from the unit and distance-to-target is determined by

measuring the time required for the echo return. Output from the PING sensor is a variable-width pulse that corresponds to the distance to the target.Interfacing to the BASIC Stamp

and Javelin Stamp microcontrollers is a snap: a single (shared) I/O pin is use to trigger the

Ping sensor and "listen" for the echo return pulse. And the intelligent trigger hold-off

allows the PING to work with the BS1! An onboard three-pin header allows the PING to be

plugged into a solder less breadboard (on a Boo-Boo, for example), and to be connected to

its host through a standard three-pin servo extension cable.

3.2 Sensor Features

The PING has only has 3 connections, which include Vdd, Vss, and 1 I/O pin.

The 3-pin header makes it easy to connect using a servo extension cable, no

soldering required.

Several sample codes are available using the Ping sensor.

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List of technical specifications:

Range - 2cm to 3m (~.75" to 10')

Supply Voltage: 5V +/-10% (Absolute: Minimum 4.5V, Maximum 6V)

Supply Current: 30 mA typ; 35 mA max

3-pin interface (power, ground, signal)

20 mA power consumption

Narrow acceptance angle

Simple pulse in / pulse out communication

Indicator LED shows measurement in progress

Input Trigger - positive TTL pulse, 2 s min, 5 s typ.

Echo Pulse - positive TTL pulse, 115 s to 18.5 ms

Echo Hold-off - 750 s from fall of Trigger pulse

Burst Frequency - 40 kHz for 200 s

Size - 22 mm H x 46 mm W x 16 mm D (0.85 in x 1.8 in x 0.6 in)

3.3 Ultrasonic Distance Transmitter unit

The circuit described generates (transmits) ultrasonic sound of frequency between

40 and 50 kHz. As with any other remote control system this circuit comprises of a mini

transmitter and a receiver circuit. Transmitter generates ultrasonic sound and the receiver

senses ultrasonic sound from the transmitter and switches on a relay.The ultrasonic

transmitter uses a 555 based astable multivibrator. It oscillates at a frequency of 40-50 kHz.

An ultrasonic transmitter transducer is used here to transmit ultrasonic sound very

effectively. The transmitter is powered from a 9-volt PP3 single cell. The ultrasonic

receiver circuit uses an ultrasonic receiver transducer to sense ultrasonic signals. It alsouses a two-stage amplifier, a rectifier stage, and an operational amplifier in inverting mode.

Output of op-amp is connected to a relay through a complimentary relay driver stage. A 9-

volt battery eliminator can be used for receiver circuit, if required. When switch S1 of

transmitter is pressed, it generates ultrasonic sound

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.

Figure 3.2: Ultrasonic transmitter

3.4 Ultrasonic Distance receiver unit

The sound is received by ultrasonic receiver transducer. It converts it to electrical

variations of the same frequency. These signals are amplified by transistors T3 and T4. The

amplified signals are then rectified and filtered. The filtered DC voltage is given to

inverting pin of op-amp IC2. The non- inverting pin of IC2 is connected to a variable DC

voltage via preset VR2 which determines the threshold value of ultrasonic signal receivedby receiver for operation of relay RL1. The inverted output of IC2 is used to bias transistor

T5. When transistor T5 conducts, it supplies base bias to transistor T6. When transistor T6

conducts, it actuates the relay. The relay can be used to control any electrical or electronic

equipment.

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Figure 3.3: Ultrasonic receiver

3.5APPLICATI

ONS

A) Transducers

An ultrasonic transducer is a device that converts energy into ultrasound, or sound waves

above the normal range of human hearing. While technically a dog whistle is an ultrasonic

transducer that converts mechanical energy in the form of air pressure into ultrasonic sound

waves, the term is more apt to be used to refer to piezoelectric transducers that convert

electrical energy into sound. Piezoelectric crystals have the property of changing size when

a voltage is applied, thus applying an alternating current (AC) across them causes them to

oscillate at very high frequencies, thus producing very high frequency sound waves.

B) Detectors

Since piezoelectric crystal generate a voltage when force is applied to them, the

same crystal can be used as an ultrasonic detector. Some systems use separate transmitter

and receiver components while others combine both in a single piezoelectric transceiver.

26

http://en.wikipedia.org/wiki/Ultrasoundhttp://en.wikipedia.org/wiki/Ultrasoundhttp://en.wikipedia.org/wiki/Dog_whistlehttp://en.wikipedia.org/wiki/Piezoelectricityhttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/AChttp://en.wikipedia.org/wiki/Ultrasoundhttp://en.wikipedia.org/wiki/Dog_whistlehttp://en.wikipedia.org/wiki/Piezoelectricityhttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/AC

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C) Use in medicine

Medical ultrasonic transducers (probes) come in a variety of different shapes and

sizes for use in making pictures of different parts of the body. The transducer may be

passed over the surface of the body or inserted into anbody opening such as the rectum orvagina. Clinicians who perform ultrasound-guided procedures often use aprobe positioning

system to hold the ultrasonic transducer.

D) Use in industry

Ultrasonic sensors are used to detect the presence of targets and to measure the

distance to targets in many automated factories and process plants. Sensors with an on or

off digital output are available for detecting the presence of objects, and sensors with an

analog output which varies proportionally to the sensor to target separation distance are

commercially available.

CHAPTER-4

DC MOTOR

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1 Introduction

DC motors are configured in many types and sizes, including brush less, servo, and

gear motor types. A motor consists of a rotor and a permanent magnetic field stator. The

magnetic field is maintained using either permanent magnets or electromagnetic windings.

DC motors are most Motion and controls cover a wide range of components that in some

way are used to generate and/or control motion. Areas within this category include bearings

and bushings, clutches and brakes, controls and drives,encoders and resolves, Integrated

motion control, limit switches, linear actuators, linear and rotary motion components, linear

position sensing, motors , orientation position sensing, pneumatics and pneumatic

components, positioning stages, slides.

Figure 4.1: DC MOTOR

Motors are the devices that provide the actual speed and torque in a drive system.

This family includes AC motor types (single and multiphase motors, universal, servo

motors, induction, synchronous, and gear motor) and DC motors (brush less, servo motor,

and gear motor) as well as linear, stepper and air motors, and motor contactors and

starters.In any electric motor, operation is based on simple electromagnetism. A current-

carrying conductor generates a magnetic field; when this is then placed in an external

magnetic field, it will experience a force proportional to the current in the conductor, and to

the strength of the external magnetic field. As you are well aware of from playing with

magnets as a kid, opposite (North and South) polarities attract, while like polarities (North

and North, South and South) repel. The internal configuration of a DC motor is designed to

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harness the magnetic interaction between a current-carrying conductor and an external

magnetic field to generate rotational motion.

4.2 Types of DC Motor

4.2.1 2-pole DC electric motor

Let's start by looking at a simple 2-pole DC electric motor (here red represents a

magnet or winding with a "North" polarization, while green represents a magnet or winding

with a "South" polarization).

Figure 4.2: 2-pole DC electric motor

Every DC motor has six basic parts -- axle, rotor (a.k.a., armature), stator,

commutator, field magnet(s), and brushes. In most common DC motors (and all that

Beamers will see), the external magnetic field is produced by high-strength permanent

magnets1. The stator is the stationary part of the motor -- this includes the motor casing, as

well as two or more permanent magnet pole pieces. The rotor (together with the axle and

attached commutator) rotates with respect to the stator. The rotor consists of windings

(generally on a core), the windings being electrically connected to the commutator. The

above diagram shows a common motor layout -- with the rotor inside the stator (field)

magnets. The geometry of the brushes, commutator contacts, and rotor windings are such

that when power is applied, the polarities of the energized winding and the stator magnet(s)

are misaligned, and the rotor will rotate until it is almost aligned with the stator's field

magnets. As the rotor reaches alignment, the brushes move to the next commutator

contacts, and energize the next winding. Given our example two-pole motor, the rotation

reverses the direction of current through the rotor winding, leading to a "flip" of the rotor's

magnetic field, and driving it to continue rotating.

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In real life, though, DC motors will always have more than two poles (three is a

very common number). In particular, this avoids "dead spots" in the commutator. You can

imagine how with our example two-pole motor, if the rotor is exactly at the middle of its

rotation (perfectly aligned with the field magnets), it will get "stuck" there. Meanwhile,

with a two-pole motor, there is a moment where the commutator shorts out the power

supply (i.e., both brushes touch both commutator contacts simultaneously). This would be

bad for the power supply, waste energy, and damage motor components as well. Yet

another disadvantage of such a simple motor is that it would exhibit a high amount of

torque ripple" (the amount of torque it could produce is cyclic with the position of the

rotor).

4.2.2 3-pole DC electric motor

So since most small DC motors are of a three-pole design, let's tinker with the

workings of one via an interactive animation (JavaScript required):

Figure4.3: 3-pole DC electric motor

You'll notice a few things from this -- namely, one pole is fully energized at a time (but two

others are "partially" energized). As each brush transitions from one commutator contact to

the next, one coil's field will rapidly collapse, as the next coil's field will rapidly charge up

(this occurs within a few microsecond). We'll see more about the effects of this later, but in

the meantime you can see that this is a direct result of the coil windings' series wiring:

There's probably no better way to see how an average dc motor is put together, than by just

opening one up. Unfortunately this is tedious work, as well as requiring the destruction of a

perfectly good motor.

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CHAPTER-5

LCD DISPLAY

5.1 INTRODUCTION

To display interactive messages we are using LCD Module. We examine an

intelligent LCD display of two lines,16 characters per line that is interfaced to the

controllers. The protocol (handshaking) for the display is as shown. Whereas D0 to D7th

bit is the Data lines, RS, RW and EN pins are the control pins and remaining pins are +5V,

-5V and GND to provide supply. Where RS is the Register Select, RW is the Read Write

and EN is the Enable pin.The display contains two internal byte-wide registers, one for

commands (RS=0) and the second for characters to be displayed (RS=1). It also contains a

user-programmed RAM area (the character RAM) that can be programmed to generate anydesired character that can be formed using a dot matrix. To distinguish between these two

data areas, the hex command byte 80 will be used to signify that the display RAM address

00h will be chosen.Port1 is used to furnish the command or data type, and ports 3.2 to3.4

furnish register select and read/write levels.The display takes varying amounts of time to

accomplish the functions as listed. LCD bit 7 is monitored for logic high (busy) to ensure

the display is overwritten.Liquid Crystal Display also called as LCD is very helpful in

providing user interface as well as for debugging purpose. The most common type of LCD

controller is HITACHI 44780 which provides a simple interface between the controller

& an LCD. These LCD's are very simple to interface with the controller as well as are cost

effective.

Figure 5.1: 2x16 Line Alphanumeric LCD Display

The most commonly used ALPHANUMERIC displays are 1x16 (Single Line & 16

characters), 2x16 (Double Line & 16 character per line) & 4x20 (four lines & Twenty

characters per line). The LCD requires 3 control lines (RS, R/W & EN) & 8 (or 4) data

lines. The number on data lines depends on the mode of operation.

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5.2 PIN DESCRIPTION

Pin Symbol Function

1 Vss Ground

2 Vdd Supply Voltage

3 Vo Contrast Setting

4 RS Register Select

5 R/W Read/Write Select

6 En Chip Enable Signal

7-14 DB0-DB7 Data Lines

15 A/Vee Gnd for the backlight

16 K Vcc for backlight

When RS is low (0), the data is to be treated as a command. When RS is high (1),

the data being sent is considered as text data which should be displayed on the screen.

When R/W is low (0), the information on the data bus is being written to the LCD. When

RW is high (1), the program is effectively reading from the LCD. The ENABLE pin is used

to latch the data present on the data pins. A HIGH - LOW signal is required to latch the

data. The LCD interprets and executes our command at the instant the EN line is brought

low.

The below figure shows LCD interfacing.

Figure 5.2: Interfacing of LCD

CHAPTER-6

SCHEMATIC DIAGRAM

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Figure 6.1: Schematic Diagram

6.1 Schematic Description

A variable regulated power supply, also called a variable bench power supply, is one

where you can continuously adjust the output voltage to your requirements. Varying the

output of the power supply is the recommended way to test a project after having double

checked parts placement against circuit drawings and the parts placement guide.

6.2 REGULATED POWER SUPPLY

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A variable regulated power supply, also called a variable bench power supply, is

one where you can continuously adjust the output voltage to your requirements. Varying

the output of the power supply is the recommended way to test a project after having

double checked parts placement against circuit drawings and the parts placement guide.

This type of regulation is ideal for having a simple variable bench power supply. Actually

this is quite important because one of the first projects a hobbyist should undertake is the

construction of a variable regulated power supply.While a dedicated supply is quite handy

e.g. 5V or 12V, it's much handier to have a variable supply on hand, especially for testing.

Most digital logic circuits and processors need a 5 volt power supply. To use these parts we

need to build a regulated 5 volt source. Usually you start with an unregulated power supply

ranging from 9 volts to 24 volts DC (A 12 volt power supply is included with the Beginner

kit and the Microcontroller Beginner Kit.). To make a 5 volt power supply, we use a

LM7805 voltage regulator IC .

Figure 6.2: IC Regulator

The LM7805 is simple to use. You simply connect the positive lead of your

unregulated DC power supply (anything from 9VDC to 24VDC) to the Input pin, connect

the negative lead to the Common pin and then when you turn on the power, you get a 5 volt

supply from the Output pin.

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Fig: Block Diagram of Power Supply

Figure 6.3: Circuit Diagram of Power Supply

Above is the circuit of a basic unregulated dc power supply. A bridge rectifier D1

to D4 rectifies the ac from the transformer secondary, which may also be a block rectifier

such as WO4 or even four individual diodes such as 1N4004 types. (See later re rectifier

ratings).The principal advantage of a bridge rectifier is you do not need a centre tap on the

secondary of the transformer. A further but significant advantage is that the ripple

frequency at the output is twice the line frequency (i.e. 50 Hz or 60 Hz) and makes filteringsomewhat easier.As a design example consider we wanted a small unregulated bench

supply for our projects. Here we will go for a voltage of about 12 - 13V at a maximum

output current (IL) of 500ma (0.5A). Maximum ripple will be 2.5% and load regulation is

5%.Now the RMS secondary voltage (primary is whatever is consistent with your area) for

our power transformer T1 must be our desired output Vo PLUS the voltage drops across

D2 and D4 (2 * 0.7V) divided by 1.414.This means that Vsec = [13V + 1.4V] / 1.414

which equals about 10.2V. Depending on the VA rating of your transformer, the secondary

voltage will vary considerably in accordance with the applied load. The secondary voltage

on a transformer advertised as say 20VA will be much greater if the secondary is only

lightly loaded.If we accept the 2.5% ripple as adequate for our purposes then at 13V this

becomes 13 * 0.025 = 0.325 Vrms. The peak to peak value is 2.828 times this value. Vrip =

0.325V X 2.828 = 0.92 V and this value is required to calculate the value of C1. Also

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required for this calculation is the time interval for charging pulses. If you are on a 60Hz

system it it 1/ (2 * 60) = 0.008333 which is 8.33 milliseconds. For a 50Hz system it is 0.01

sec or 10 milliseconds.Remember the tolerance of the type of capacitor used here is very

loose. The important thing to be aware of is the voltage rating should be at least 13V X

1.414 or 18.33. Here you would use at least the standard 25V or higher (absolutely not

16V).With our rectifier diodes or bridge they should have a PIV rating of 2.828 times the

Vsec or at least 29V. Don't search for this rating because it doesn't exist. Use the next

highest standard or even higher. The current rating should be at least twice the load current

maximum i.e. 2 X 0.5A or 1A. A good type to use would be 1N4004, 1N4006 or 1N4008

types.These are rated 1 Amp at 400PIV, 600PIV and 1000PIV respectively. Always be on

the lookout for the higher voltage ones when they are on special type of regulation is ideal

for having a simple variable bench power supply. Actually this is quite important because

one of the first projects a hobbyist should undertake is the construction of a variable

regulated power supply.

6.3 Circuit Features:

Brief description of operation: Gives out well regulated +5V output, output current

capability of 100 mA

Circuit protection: Built-in overheating protection shuts down output when

regulator IC gets too hot

Circuit complexity: Very simple and easy to build

Circuit performance: Very stable +5V output voltage, reliable operation

Availability of components: Easy to get, uses only very common basic components

Design testing: Based on datasheet example circuit, I have used this circuit

successfully as part of many electronics projects Applications:

Part of electronics devices, small laboratory power supply

Power supply voltage: Unregulated DC 8-18V power supply

Power supply current: Needed output current + 5 mA

Component costs: Few dollars for the electronics components + the input

transformer cost

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CHAPTER 7

SOFTWARE DESCRIPTION

Click on the Keil uVision Icon on Desktop

The following fig will appear

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Click on the Project menu from the title bar

Then Click on New Project

Save the Project by typing suitable project name with no extension in u r own

folder sited in either C:\ or D:\

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Then Click on Save button above.

Select the component for u r project. i.e. Atmel

Click on the + Symbol beside of Atmel

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Select AT89S51 as shown below

Then Click on OK

The Following fig will appear

Then Click either YES or NOmostly NO

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Now your project is ready to USE

Now double click on the Target1, you would get another option Source group 1

as shown in next page.

Click on the file option from menu bar and select new

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The next screen will be as shown in next page, and just maximize it by double

clicking on its blue boarder.

Now start writing program in either in C or ASM

For a program written in Assembly, then save it with extension . asm and for

C based program save it with extension .C

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Now right click on Source group 1 and click on Add files to Group Source

Now you will get another window, on which by default C files will appear.

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Now select as per your file extension given while saving the file

Click only one time on option ADD

Now Press function key F7 to compile. Any error will appear if so happen.

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If the file contains no

error, then press Control+F5 simultaneously.

The new window is as follows

Then Click OK

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Now Click on the Peripherals from menu bar, and check your required port as

shown in fig below

Drag the port a side and click in the program file.

Now keep Pressing function key F11 slowly and observe.

You are running your program successfully

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FUTURE SCOPE

This system is a rapidly growing field and there are new and improved

strategies popping up all the time. For the most part these systems are all built around the

same basic structure, a central box that monitors several detectors and perimeter guards and

sounds an alarm when any of them are triggered.This system is best for guiding the

perimeter of a house or a business center the points where an intruder would enter the

building. In this system IR sensor is used to detect the intrusion. Similarly the vibration and

temperature sensors recognize vibration disturbances and accidental fires respectively.This

project provides an efficient and economical security system. This system finds

applications in industries, banks and homes.

Incorporating the features discussed below can further enhance the system

This system can detect intrusion only at discrete points. This system detection

feature can be extended to scanning a complete area. Thus the intrusion into the

building can be detected with much more efficiently.

The redialing feature can also be incorporated such that if the call is not put forward

the first time, the auto dialer will dial the same number until the call is successfully

completed.

A pre-recorded voice message can delivered to the owner notifying him about the

intrusion into the premises.

The addition of the above discussed advancements certainly builds this project into

a much flexible and reliable security system.

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REFERENCES

The 8051 Microcontroller and Embedded Systems By Muhammad Ali Mazidi

Fundamentals Of Embedded Software By Daniel W Lewis

www.howsstuffworks.com

www.alldatasheets.com

www.electronicsforu.com

www.knowledgebase.com

www.8051 projectsinfo.com

Datasheets of Microcontroller AT89C52

Datasheets of 555 timer

Datasheets of TSAL 6200

Datasheets of TSOP 1356

Datasheets of BC 547

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Datasheets of DTMF Generator UM 95089