automatic railway gate

DESCRIPTION CONTENTS PAGE NO.

LIST OF FIGURE

LIST OF TABLES

ABSTRACT 07

CHAPTER -1

INTRODUCTION TO AUTOMATIC RAILWAY SYSTEM

1.1 Introduction 08

1.2Embedded systems 08

1.3 Examples of embedded systems 09

CHAPTER -2

BLOCK DIAGRAM OF AUTOMATIC RAILWAY GATE

2.1 Block diagram 11

2.2 Power supply 11

2.3 Transformers 12

2.4 Rectifiers 13

2.4.1 Types of Rectifiers 13

2.5 Micro controller (AT89S51) 16

2.5.1 Description 16

2.5.2 Features 17

2.5.3 Block diagram and pin diagram 18

2.6 Oscillator 22

B.TECH(EEE),H.I.T.S (COE) Page 1 Department of EEE

CHAPTER -3

3.1 IR COMMUNICATIONS 23

3.1.1 IR Generation 25

3.2 IR LED AND IR SENSOR 26

3.2.1 Schematic circuit of IR sensors 26

3.3 IR TRANSMITTER 28

3.4 IR RECEIVER 30

3.4.1 Use of Infrared detector 31

3.4.2 Theory of sensor circuit 34

3.4.3 Applications of sensors 37

3.5 Introduction to dc motors 39

3.5.1 Introduction 39

3.5.2 Main parts of dc motors 43

3.5.3 Working of dc motor 46

3.5.4 Speed control of dc motor 49

3.6 Motor driver circuit (H-bridge) 52

3.6.1 Operating modes of H-bridge 52


CHAPTER-4

SOFTWARE EXPLANATION

4.1 Introduction to KEIL software 54

4.2 KEIL software tools (STEPS) 55

CHAPTER -5

CONCLUSION 61

BIBILOGRAPHY 62

REFRENCES 62


LIST OF FIGURES

FIGURES PAGE NO

1.1 INTERNAL PART OF EMBEDDED SYSTEM 9

2.1 BLOCK DIAGRAM OF PROJECT 11

2.2 COMPONENTS OF POWER SUPPLY 12

2.3 AN ELECTRICAL TRANSFORMER 12

2.4 FULL WAVE RECTIFIER 15

2.5 POSITIVE CYCLE FULL WAVE RECTIFIER 15

2.6 NEGATIVE CYCLE OF FULL WAVE RECTIFIER 15

2.7MICRO CONTROLLERS 16

2.8 BLOCK DIAGRAM OF MICRO CONTROLLER 18

2.9 PIN DIAGRAM OF MICRO CONTROLLER 18

2.10 OSCILLATOR CONNECTIONS 22

2.11 EXTERNAL CLOCK DRIVE CONFIGURATION 22

3.1 VISIBLE SPECTRUMS 23

3.2 CIRCUIT DIAGRAM OF IR SENSOR 28

3.3 IR LED 28

3.4 OP AMPS 30

3.5 IR EMITTER AND IR PHOTO TRANSISTOR 31

3.6 CIRCUIT DIAGRAM OF INFRARED REFLECTANCE SENSOR 32


3.7 SCHEMATIC DIAGRAM OF SINGLE PAIR IR TRANSMITTER 33

3.8 SCHEMATIC OF SINGLE SENSOR 34

3.9 DESCRIPTION OF OPERATION OF A TYPICAL CIRCUIT 35

3.10 OPERATION OF LED’S 35

3.11 CHARACTERISTICS OF LED’S 36

3.12 COMMUTATORS 43

3.13 BRUSHES 44

3.14 COMMUTATORS AND COMMUTATOR RING 45

3.15 POSITIVE AND NEGATIVE COUNTER CLOCKWISE ROTATION 46

3.16 WORKING OF DC MOTOR 47

3.17 PERIPHERAL OF DC MOTOR 48

3.18 CONSTRUCTION AND WORKING OF DC MOTOR 48

3.19 SPEED CURVE OF DC MOTOR 49

3.20 MOTOR TORQUES LOADING 50

3.21 H-BRIDGE CONNECTED TO A MOTOR 52

3.22 CURRENT FLOWING IN HIGH SIDE AND LOW SIDE 53


LIST OF TABLES

TABLES PAGE NO

2.1 COMPARISONS OF RECTIFIERS 13

2.2 OPERATIONS OF PORTS 19

3.1 DIFFERENT MATERIALS AND THEIR WAVE LENGTHS 39

3.2 TRUTH TABLE 53


ABSTRACT:

The railroad industry’s own desire to maintain their ability to provide safe and secure

transport of their customers’ hazardous materials has introduced new challenges in rail security.

Addressing these challenges is important as railroads, and the efficient delivery of their cargo,

play a vital role in the economy of the country.

The train driver always observes the signals placed beside the track. These signals are

controlled from the control room. The green light denotes that the track is free and red light

denotes the track is busy. These signals are controlled based on the train position which is sensed

by the using the IR sensors placed along the track.

The present project is designed to satisfy the security needs of the railways. This system

provides the security in two ways: Automatic gate opening/closing system at track crossing,

signaling for the train driver. The automatic gate opening/closing system is provided with the IR

sensors placed at a distance of few kilometres on the both sides from the crossing road. These

sensors give the train reaching and leaving status to the embedded controller at the gate to which

they are connected. The controller operates (open/close) the gate as per the received signal from

the IR sensors.


CHAPTER-1

INTRODUCTION TO AUTOMATIC RAILWAY GATE

1.1 INTRODUCTION

Whenever ir senses the coming up of train then automatically gate will be closed.

If there is no obstacle found in between ir pairs then gate will be opened.This

particular operation will be handled by the dc motor along with h-bridge interfaced

with micro controller.

Firstly, the required operating voltage for Microcontroller 89C51 is 5V. Hence

the 5V D.C. power supply is needed by the same. This regulated 5V is generated by

first stepping down the 230V to 9V by the step down transformer.

The step downed a.c. voltage is being rectified by the Bridge Rectifier. The

diodes used are 1N4007. The rectified a.c voltage is now filtered using a ‘C’ filter.

Now the rectified, filtered D.C. voltage is fed to the Voltage Regulator. This voltage

regulator allows us to have a Regulated Voltage which is +5V.

The rectified; filtered and regulated voltage is again filtered for ripples using

an electrolytic capacitor 100μF. Now the output from this section is fed to 40th pin of

89c51 microcontroller to supply operating voltage.The microcontroller 89c51 with

Pull up resistors at Port0 and crystal oscillator of 11.0592 MHz crystal in conjunction

with couple of capacitors of is placed at 18 th& 19th pins of 89c51 to make it work

(execute) properly.

1.2 EMBEDDED SYSTEM:

An embedded system is a special-purpose system in which the computer is

completely encapsulated by or dedicated to the device or system it controls. Unlike a general-

purpose computer, such as a personal computer, an embedded system performs one or a few

predefined tasks, usually with very specific requirements. Since the system is dedicated to


specific tasks, design engineers can optimize it, reducing the size and cost of the product.

Embedded systems are often mass-produced, benefiting from economies of scale.

Personal digital assistants (PDAs) or handheld computers are generally considered

embedded devices because of the nature of their hardware design, even though they are more

expandable in software terms. This line of definition continues to blur as devices expand.

With the introduction of the OQO Model 2 with the Windows XP operating system and ports

such as a USB port — both features usually belong to "general purpose computers", — the

line of nomenclature blurs even more.

Physically, embedded systems ranges from portable devices such as digital

watches and MP3 players, to large stationary installations like traffic lights, factory

controllers, or the systems controlling nuclear power plants.

In terms of complexity embedded systems can range from very simple with a single

microcontroller chip, to very complex with multiple units, peripherals and networks mounted inside

a large chassis or enclosure.

Fig.1.1 INTERNAL PART OF EMBEDDED SYSTEM


1.3 APPLICATIONS OF EMBEDDED SYSTEMS:

Avionics, such as inertial guidance systems, flight control hardware/software and

other integrated systems in aircraft and missiles

Cellular telephones and telephone switches

Engine controllers and antilock brake controllers for automobiles

Home automation products, such as thermostats, air conditioners, sprinklers, and

security monitoring systems

Handheld calculators

Handheld computers

Household appliances, including microwave ovens, washing machines, television sets,

DVD players and recorders

Medical equipment

Personal digital assistant

Videogame consoles

Computer peripherals such as routers and printers.

Industrial controllers for remote machine operation.


CHAPTER-2

BLOCK DIAGRAM OF AUTOMATIC RAILWAY GATE

2.1 BLOCK DIAGRAM:

Fig:2.1 Block Diagram of project

2.2 POWER SUPPLY:

The power supplies are designed to convert high voltage AC mains electricity to a

suitable low voltage supply for electronic circuits and other devices. A power supply can by

broken down into a series of blocks, each of which performs a particular function. A d.c

power supply which maintains the output voltage constant irrespective of a.c mains

fluctuations or load variations is known as “Regulated D.C Power Supply”. For example a 5V

regulated power supply system as shown below:


Fig: 2.2 Components of power supply

2.3TRANSFORMER:

A transformer is an electrical device which is used to convert electrical power from one

Electrical circuit to another without change in frequency.Transformers convert AC electricity

from one voltage to another with little loss of power. Transformers work only with AC and

this is one of the reasons why mains electricity is AC. Step-up transformers increase in

output voltage, step-down transformers decrease in output voltage. Most power supplies use a

step-down transformer to reduce the dangerously high mains voltage to a safer low voltage.

The input coil is called the primary and the output coil is called the secondary. There

is no electrical connection between the two coils; instead they are linked by an alternating

magnetic field created in the soft-iron core of the transformer. The two lines in the middle of

the circuit symbol represent the core. Transformers waste very little power so the power out

is (almost) equal to the power in. Note that as voltage is stepped down current is stepped up.

The ratio of the number of turns on each coil, called the turn’s ratio, determines the ratio of

the voltages. A step-down transformer has a large number of turns on its primary (input) coil

which is connected to the high voltage mains supply, and a small number of turns on its

secondary (output) coil to give a low output voltage.

Fig: 2.3An Electrical Transformer


2.4 RECTIFIER:

A circuit which is used to convert ac to dc is known as RECTIFIER. The process of

conversion ac to dc is called “rectification”

2.4.1 TYPES OF RECTIFIERS:

Half wave Rectifier

Full wave rectifier

1. Centre tap full wave rectifier.

2. Bridge type full bridge rectifier.

Comparison of rectifier circuits:

Parameter

Type of Rectifier

Half wave Full wave Bridge

Number of diodes

1 2 4

PIV of diodes

Vm 2Vm Vm

D.C output voltage Vm/ 2Vm/ 2Vm/

Vdc,at

no-load

0.318Vm 0.636Vm 0.636Vm

Ripple factor 1.21 0.482 0.482

Ripple


frequency f 2f 2f

Rectification

efficiency 0.406 0.812 0.812

Transformer

Utilization

Factor(TUF)

0.287 0.693 0.812

RMS voltage Vrms Vm/2 Vm/√2 Vm/√2

Table: 2.1 Comparisons of rectifiers

FULL-WAVE RECTIFIER:

From the above comparison we came to know that full wave bridge rectifier as more advantages than the other two rectifiers. So, in our project we are using full wave bridge rectifier circuit.

BRIDGE RECTIFIER:

A bridge rectifier makes use of four diodes in a bridge arrangement to achieve full-

wave rectification. This is a widely used configuration, both with individual diodes wired as

shown and with single component bridges where the diode bridge is wired internally.

A bridge rectifier makes use of four diodes in a bridge arrangement as shown in fig

(a) to achieve full-wave rectification. This is a widely used configuration, both with

individual diodes wired as shown and with single component bridges where the diode bridge

is wired internally.


Fig: 2.4 Full wave rectifier

OPERATION:

During positive half cycle of secondary, the diodes D2 and D3 are in forward biased while

D1 and D4 are in reverse biased as shown in the fig(b). The current flow direction is shown

in the fig (b) with dotted arrows.

Fig: 2.5 Positive cycle full wave rectifier

During negative half cycle of secondary voltage, the diodes D1 and D4 are in forward biased

while D2 and D3 are in reverse biased as shown in the fig(c). The current flow direction is

shown in the fig (c) with dotted arrows.

Fig: 2.6 Negative cycle of full wave rectifier


2.5 MICRO CONTROLLER (AT89S51)

2.5.1 DESCRIPTION:

The AT89S51 is a low-power, high-performance CMOS 8-bit microcontroller with 4K

bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high-

density non-volatile memory technology and is compatible with the industry- standard 80C51

instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-

system or by a conventional non-volatile memory programmer. By combining a versatile 8-bit

CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S51 is a powerful

microcontroller which provides a highly-flexible and cost-effective solution to many embedded

control applications. A Micro controller consists of a powerful CPU tightly coupled with

memory, various I/O interfaces such as serial port, parallel port timer or counter, interrupt

controller, data acquisition interfaces-Analog to Digital converter, Digital to Analog converter,

integrated on to a single silicon chip.

If a system is developed with a microprocessor, the designer has to go for external

memory such as RAM, ROM, EPROM and peripherals. But controller is provided all these

facilities on a single chip. Development of a Micro controller reduces PCB size and cost of design.

One of the major differences between a Microprocessor and a Micro controller is that a controller often deals with bits not bytes as in the real world application.

Intel has introduced a family of Micro controllers called the MCS-51.

Fig: 2.7 Micro controllers


2.5.2 FEATURES:

• Compatible with MCS-51® Products

• 4K Bytes of In-System Programmable (ISP) Flash Memory

– Endurance: 1000 Write/Erase Cycles

• 4.0V to 5.5V Operating Range

• Fully Static Operation: 0 Hz to 33 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

• Full Duplex UART Serial Channel

• Low-power Idle and Power-down Modes

.


2.5.3 BLOCK DIAGRAM AND PIN DIAGRAM:

Fig: 2.8 Block diagram of micro controller

PIN DIAGRAM:

Fig: 2.9 Pin diagram of micro controller


PIN DESCRIPTION:

VCC - Supply voltage.

GND - Ground.

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 high-impedance

inputs. Port 0 can also be configured to be the multiplexed low-order address/data bus during

accesses to external program and data memory. In this mode, P0 has internal pull-ups. Port 0 also

receives the code bytes during Flash programming and outputs the code bytes during program

verification. External pull-ups are required during program verification.

Port 1:

Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. 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 pull-ups 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 pull-ups. Port 1 also receives the low-

order address bytes during Flash programming and verification.

Table: 2.2 Operations of ports


Port 2:



internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being

pulledlow will source current (IIL) because of the internal pull-ups. Port 2 also receives the high-

order address bits and some control signals during Flash programming and verification.

Port 3:



internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled

low will source current (IIL) because of the pull-ups. Port 3 receives some control signals for

Flash programming and verification. Port 3 also serves the functions of various special features of

the AT89S51, as shown in the following table.

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 98 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

AT89S51 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.

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.


2.6 OSCILLATOR:

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier

which can be configured for use as an on-chip oscillator, as shown in Figs 6.2.3. Either a

quartz crystal or ceramic resonator may be used. To drive the device from an external clock

source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure

2.11.There are no requirements on the duty cycle of the external clock signal, since the input

to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and

maximum voltage high and low time specifications must be observed.

Fig: 2.10 Oscillator Connections Fig: 2.11 External Clock Drive Configuration


CHAPTER-3

3.1 IR COMMUNICATIONS

IR wireless is the use of wireless technology in devices or systems that convey data

through infrared (IR) radiation. Infrared is electromagnetic energy at a wavelength or

wavelengths somewhat longer than those of red light. The shortest-wavelength IR borders

visible red in the spectrum. The longest-wavelength IR borders radio waves.

The name means below red, the Latin infra meaning "below". Red is the color of the longest

wavelengths of visible light. Infrared light has a longer wavelength (and so a lower

frequency) than that of red light visible to humans, hence the literal meaning of below red.

INFRARED ENERGY is light that we cannot see, but our bodies can detect as heat. It is part

of the electromagnetic spectrum that includes radio waves, X-rays and visible light. All of

these forms of energy have a specific frequency, as represented in the chart below.

Fig: 3.1 Visible spectrums

Infrared energy is comprised of those frequencies that exist just below the red end of the

visible spectrum, and for cooking properties they have a very unique benefit - when they

strike organic molecules (such as any type of food), they cause the molecules to vibrate,

thereby creating heat. Although almost any type of electromagnetic energy can cause heating,

for the purpose of cooking, infrared energy is the perfect choice.

IR wireless is used for short- and medium-range communications and control. Some systems

operate in line-of-sight mode; this means that there must be a visually unobstructed straight

line through space between the transmitter (source) and receiver (destination). Other systems


http://en.wikipedia.org/wiki/Frequency

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operate in diffuse mode, also called scatter mode. This type of system can function when the

source and destination are not directly visible to each other. An example is a

televisionRemote-control box. The box does not have to be pointed directly at the set,

although the box must be in the same room as the set, or just outside the room with the door

open.

IR wireless technology is used in intrusion detectors; home-entertainment control units; robot

control systems; medium-range, line-of-sight laser communications; cordless microphones,

headsets, modems, and printers and other peripherals.Infrared is an energy radiation with a

frequency below our eyes sensitivity, so we cannot see it. Even that we cannot "see" sound

frequencies, we know that it exist, we can listen them.

Even that we cannot see or hear infrared, we can feel it at our skin temperature sensors.

When you approach your hand to fire or warm element, you will "feel" the heat, but you can't

see it. You can see the fire because it emits other types of radiation, visible to your eyes, but

it also emits lots of infrared that you can only feel in your skin.

INFRARED IN ELECTRONICS

Infra-Red is interesting, because it is easily generated and doesn't suffer electromagnetic

interference, so it is nicely used to communication and control, but it is not perfect, some

other light emissions could contains infrared as well, and that can interfere in this

communication. The sun is an example, since it emits a wide spectrum or radiation.

The adventure of using lots of infra-red in TV/VCR remote controls and other applications,

brought infra-red diodes (emitter and receivers) at very low cost at the market. From now on

you should think as infrared as just a "red" light. This light can means something to the

receiver, the "on or off" radiation can transmit different meanings. Lots of things can generate


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infrared, anything that radiate heat do it, including out body, lamps, stove, oven, friction your

hands together, even the hot water at the faucet.

To allow a good communication using infra-red, and avoid those "fake" signals, it is

imperative to use a "key" that can tell the receiver what is the real data transmitted and what

is fake. As an analogy, looking eye naked to the night sky you can see hundreds of stars, but

you can spot easily a faraway airplane just by its flashing strobe light. That strobe light is the

"key", the "coding" element that alerts us.

Similar to the airplane at the night sky, our TV room may have hundreds of tinny IR sources,

our body and the lamps around, even the hot cup of tea. A way to avoid all those other

sources, is generating a key, like the flashing airplane. So, remote controls use to pulsate its

infrared in a certain frequency. The IR receiver module at the TV, VCR or stereo "tunes" to

this certain frequency and ignores all other IR received. The best frequency for the job is

between 30 and 60 kHz, the most used is around 36 kHz

3.1.1 IR GENERATION

To generate a 36 kHz pulsating infrared is quite easy, more difficult is to receive and

identify this frequency. This is why some companies produce infrared receives, that contains

the filters, decoding circuits and the output shaper, that delivers a square wave, meaning the

existence or not of the 36kHz incoming pulsating infrared.It means that those 3 dollars small


units, have an output pin that goes high (+5V) when there is a pulsating 36kHz infrared in

front of it, and zero volts when there is not this radiation.

A square wave of approximately 27uS (microseconds) injected at the base of a transistor, can

drive an infrared LED to transmit this pulsating light wave. Upon its presence, the

commercial receiver will switch its output to high level (+5V).If you can turn on and off this

frequency at the transmitter; your receiver's output will indicate when the transmitter is on or

off. Those IR demodulators have inverted logic at its output, when a burst of IR is sensed it

drives its output to low level, meaning logic level = 1.

The TV, VCR, and Audio equipment manufacturers for long use infra-red at their

remote controls. To avoid a Philips remote control to change channels in a Panasonic TV,

they use different codification at the infrared, even that all of them use basically the same

transmitted frequency, from 36 to 50 kHz. So, all of them use a different combination of bits

or how to code the transmitted data to avoid interference.

3.2 IR LED AND IR SENSOR

3.2.1 SCHEMATIC CIRCUIT IR SENSOR

IR LED is used as a source of infrared rays. It comes in two packages 3mm or 5mm.

3mm is better as it is requires less space. IR sensor is nothing but a diode, which is sensitive

for infrared radiation.

This infrared transmitter and receiver are called as IR TX-RX pair. It can be

obtained from any decent electronics component shop and costs less than 10Rs. Following

snap shows 3mm and 5mm IR pairs. Color of IR transmitter and receiver is different.

However you may come across pairs which appear exactly same or even has opposite


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colorsthan shown in above picture and it is not possible to distinguish between TX and RX

visually. In case you will have to take help of multi-meter to distinguish between them.

Here is how you can distinguish between IR TX-RX using DMM:

Connect cathode of one LED to +ve terminal of DMM

Connect anode of the same LED to common terminal of DMM

(means connect LED such that It gets reverse biased by DMM )

Set DMM to measure resistance up to 2M Ohm.

Check the reading.

Repeat above procedure with second LED.

In above process, when you get the reading of the few hundred Kilo Ohms on DMM,

then it indicated that LED that you are testing is IR sensor. In case of IR transmitter

DMM will not show any reading.

Following snap shows typical DMM reading obtained when IR receiver is connected

to it as mentioned above. Second snap shows how sensor’s resistance increases when it is

covered by a finger. Note that, these are just illustrative figures and they will depend upon

sensor as well as DMM that you are using.

While buying an IR sensor, make sure that its reverse resistance in ambient light is

below 1000K. If it is more than this value, then it will not be able to generate sufficient

voltage across external resistor and hence will be less sensitive to small variation in incident

light.


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The circuit diagram::Circuit diagram for IR sensor module is very simple and straight

forward.

Fig: 3.2 Circuit diagram of IR sensor

Circuit is divided into two sections. IR TX and IR RX are to be soldered on small general

purpose Grid PCB. From this module, take out 3 wires of sufficiently long length (say 1 ft).

Then, as shown above, connect them to VCC, present and to ground on main board. By

adjustingpreset, you can adjust sensitivity of the sensor. VCC should be connected to 5V

supply.

3.3 IR TRANSMITTER

Fig: 3.3 IR led


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IR LED emits infrared radiation. This radiation illuminates the surface in front of

LED. Surface reflects the infrared light. Depending on the reflectivity of the surface, amount

of light reflected varies. This reflected light is made incident on reverse biased IR sensor.

When photons are incident on reverse biased junction of this diode, electron-hole pairs are

generated, which results in reverse leakage current. Amount of electron-hole pairs generated

depends on intensity of incident IR radiation. More intense radiation results in more reverse

leakage current. This current can be passed through a resistor so as to get proportional

voltage. Thus as intensity of incident rays varies, voltage across resistor will vary

accordingly.

This voltage can then be given to OPAMP based comparator. Output of the

comparator can be read by uc. Alternatively, you can use on-chip ADC in AVR

microcontroller to measure this voltage and perform comparison in software.


Fig: 3.4 Op amps

3.4 IR RECEIVER:

A photodiode is a type of photo detector capable of converting light into either current

or voltage, depending upon the mode of operation. Photodiodes are similar to regular

semiconductor diodes except that they may be either exposed (to detect vacuum UV or X-

rays) or packaged with a window or optical fiber connection to allow light to reach the

sensitive part of the device. Many diodes designed for use specifically as a photodiode will

also use a PIN junction rather than the typical PN junction.


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3.4.1USE OF INFRARED DETECTORS BASICS

Fig: 3.5IR Emitter and IR Photo transistor

An infrared emitter is an LED made from gallium arsenide, which emits near-infrared

energy at about 880nm. The infrared phototransistor acts as a transistor with the base voltage

determined by the amount of light hitting the transistor. Hence it acts as a variable current

source. Greater amount of IR light cause greater currents to flow through the collector-emitter

leads. As shown in the diagram below, the phototransistor is wired in a similar configuration

to the voltage divider. The variable current traveling through the resistor causes a voltage

drop in the pull-up resistor. This voltage is measured as the output of the device.


http://irbasic.blogspot.com/2006/11/use-of-infrared-detectors-basics.html

Fig: 3.6 Circuit diagram of infrared reflectance sensor

IR reflectance sensors contain a matched infrared transmitter and infrared receiver

pair. These devices work by measuring the amount of light that is reflected into the receiver.

Because the receiver also responds to ambient light, the device works best when well

shielded from ambient light, and when the distance between the sensor and the reflective

surface is small(less than 5mm). IR reflectance sensors are often used to detect white and

black surfaces. White surfaces generally reflect well, while black surfaces reflect poorly. Of

such applications is the line follower of a robot.


:

Schematic diagram for a single pair of infrared transmitter and receiver

Fig: 3.7 Schematic diagram of single pair IR transmitter


3.4.2 THEORY OF SINGLE SENSOR CIRCUIT

Fig: 3.8 Schematic of single sensor

To get a good voltage swing , the value of R1 must be carefully chosen.

If IR sensor = a when no light falls on it and IR sensor = b when light falls on it.

The difference in the two potentials is:

Vcc * { a/(a+R1) - b/(b+R1) }

Relative voltage swing = Actual Voltage Swing / Vcc

= Vcc * { a/(a+R1) - b/(b+R1) } / Vcc

= a/(a+R1) - b/(b+R1)

The resistance of the sensor decreases when IR light falls on it. A good sensor will

have near zero resistance in presence of light and a very large resistance in absence of light.

We have used this property of the sensor to form a potential divider. The potential at point ‘2’

isRsensor / (Rsensor + R1). Again, a good sensor circuit should give maximum change in

potential at point ‘2’ for no-light and bright-light conditions. This is especially important is

you plan to use an ADC in place of the comparator To get a good voltage swing , the value of

R1 must be carefully chosen. If Rsensor = a when no light falls on it and Rsensor = b when

light falls on it. The difference in the two potentials is:

Vcc * { a/(a+R1) - b/(b+R1) }

Relative voltage swing = Actual Voltage Swing / Vcc


= Vcc * { a/(a+R1) - b/(b+R1) } / Vcc

fig: 3.9Description of operation of a typical circuit

fig: 3.10 Operation of led’s

If the emitter and detector (aka phototransistor) are not blocked, then the output on

pin 2 of the 74LS14 will be high (app. 5 Volts). When they are blocked, then the output will

be low (app. 0 Volts). The 74LS14 is a Schmitt triggered hex inverter. A Schmitt trigger is a

signal conditioner. It ensures that above a threshold value, we will always get "clean" HIGH

and LOW signals. Not Blocked Case: Pin 2 High Current from Vcc flows through the

detector. The current continues to flow through the base of Q2. Current from Vcc also flows

through R2, and Q2's Drain and Emitter to ground. As a result of this current path, there will

be no current flowing through Q1's base. The signal at U1's pin 1 will be low, and so pin 2


will be high. Therefore only the moderated signal from the light emitter can be detected.

Of course the detector must not be saturated by ambient light; this is effective when the

detector

Fig: 3.11 Characteristics of led’s

the line position is compared to the centre value to be tracked, the position error is processed

with Proportional /Integral/ Diffence filter. to generate steering command. The line following

robot tracks the line in PID control that the most popular algorithm for servo control. The


proportional term is the common process in the servo system. It is only a gain amplifier

without time dependent process. The differential term is applied in order to improve the

response to disturbance, and it also compensate phase lag at the controlled object. The D term

will be required in most case to stabilize tracking motion. The I term that boosts DC gain is

applied in order to remove left offset error, however, it often decrease servo stability due to

its phase lag. When any line sensing error has occurred for a time due to getting out of line or

end of line, the motors are stopped and the microcontroller enters sleep state of zero power

consumption. Typical Examples of infrared Transmitter and Receiver installation.

3.4.3 APPLICATIONS OF SENSORS

A photodiode is a type of photo detector capable of converting light into either

current or voltage, depending upon the mode of operation. Photodiodes are similar to regular

semiconductor diodes except that they may be either exposed (to detect vacuum UV or X-

rays) or packaged with a window or optical fibre connection to allow light to reach the

sensitive part of the device. Many diodes designed for use specifically as a photodiode will

also use a PIN junction rather than the typical PN junction.

PRINCIPLE OF POERATION

A photodiode is a PN junction or PIN structure. When a photon of sufficient energy

strikes the diode, it excites an electron thereby creating a mobile electron and a positively

charged electron hole. If the absorption occurs in the junction's depletion region, or one

diffusion length away from it, these carriers are swept from the junction by the built-in field

of the depletion region. Thus holes move toward the anode, and electrons toward the cathode,

and a photocurrent is produced.

PHOTOVOTAIC MODE

When used in zero bias or photovoltaic mode, the flow of photocurrent out of the

device is restricted and a voltage builds up. The diode becomes forward biased and "dark

current" begins to flow across the junction in the direction opposite to the photocurrent. This


http://en.wikipedia.org/wiki/Bias_(electrical_engineering)

http://en.wikipedia.org/wiki/Photon

http://en.wikipedia.org/wiki/PIN_diode



http://en.wikipedia.org/wiki/Optical_fiber



http://en.wikipedia.org/wiki/Electric_current

http://en.wikipedia.org/wiki/Light

mode is responsible for the photovoltaic effect, which is the basis for solar cells—in fact, a

solar cell is just an array of large photodiodes.

PHOTOCONDUCTIVE MODE

In this mode the diode is often (but not always) reverse biased. This increases the

width of the depletion layer, which decreases the junction's capacitance resulting in faster

response times. The reverse bias induces only a small amount of current (known as saturation

or back current) along its direction while the photocurrent remains virtually the same.

Although this mode is faster, the photovoltaic mode tends to exhibit less electronic noise

(The leakage current of a good PIN diode is so low – < 1nA – that the Johnson–Nyquist noise

of the load resistance in a typical circuit often dominates.)Avalanche photodiodes have a

similar structure to regular photodiodes, but they are operated with much higher reverse bias.

This allows each photo-generated carrier to be multiplied by avalanche breakdown, resulting

in internal gain within the photodiode, which increases the effective responsively of the

device.

PHOTOTRANSISTERS also consist of a photodiode with internal gain. A phototransistor

is in essence nothing more than a bipolar transistor that is encased in a transparent case so

that light can reach the base-collector junction. The electrons that are generated by photons in

the base-collector junction are injected into the base, and this current is amplified by the

transistor operation. Note that although phototransistors have a higher responsivity for light

they are unable to detect low levels of light any better than photodiodes. Phototransistors also

have slower response times.

MATERIALS

The material used to make a photodiode is critical to defining its properties, because

only photons with sufficient energy to excite electrons across the material's bandgap will

produce significant photocurrents.

Materials commonly used to produce photodiodes include:


http://en.wikipedia.org/wiki/Responsivity

http://en.wikipedia.org/wiki/Capacitance

http://en.wikipedia.org/wiki/P-n_junction#Reverse-bias

http://en.wikipedia.org/wiki/Solar_cell

http://en.wikipedia.org/wiki/Photovoltaic_effect

Material Wavelength range (nm)

Silicon 190–1100

Germanium 400–1700

Indium gallium

arsenide800–2600

Lead sulphide <1000-3500

Table: 3.1 Different materials and their wave lengths

Because of their greater band gap, silicon-based photodiodes generate less noise than

germanium-based photodiodes, but germanium photodiodes must be used for wavelengths

longer than approximately 1 µm.

Since transistors and ICs are made of semiconductors, and contain P-N junctions,

almost every active component is potentially a photodiode. Many components, especially

those sensitive to small currents, will not work correctly if illuminated, due to the induced

photocurrents. In most components this is not desired, so they are placed in an opaque

housing. Since housings are not completely opaque to X-rays or other high energy radiation,

these can still cause many ICs to malfunction due to induced photo-currents.

3.5 INTRODUCTION TO DC MOTORS:

3.5.1INTRODUCTION:

The brushed DC motor is one of the earliest motor designs. Today, it is the motor of

choice in the majority of variable speed and torque control applications.


Advantages:

Easy to understand design

Easy to control speed

Easy to control torque

Simple, cheap drive design

Easy to understand design

The design of the brushed DC motor is quite simple. A permanent magnetic field is

created in the stator by either of two means:

Permanent magnets

Electro-magnetic windings

If the field is created by permanent magnets, the motor is said to be a "permanent magnet

DC motor" (PMDC). If created by electromagnetic windings, the motor is often said to be a

"shunt wound DC motor" (SWDC). Today, because of cost-effectiveness and reliability, the

PMDC motor is the motor of choice for applications involving fractional horsepower DC

motors, as well as most applications up to about three horsepower. At five horsepower and

greater, various forms of the shunt wound DC motor are most commonly used. This is

because the electromagnetic windings are more cost effective than permanent magnets in this

power range.

Caution: If a DC motor suffers a loss of field (if for example, the field power connections

are broken), the DC motor will immediately begin to accelerate to the top speed which the

loading will allow. This can result in the motor flying apart if the motor is lightly loaded. The

possible loss of field must be accounted for, particularly with shunt wound DC motors.

Opposing the stator field is the armature field, which is generated by a changing

electromagnetic flux coming from windings located on the rotor. The magnetic poles of the

armature field will attempt to line up with the opposite magnetic poles generated by the stator


field. If we stopped the design at this point, the motor would spin until the poles were

opposite one another, settle into place, and then stop -- which would make a pretty useless

motor!

However, we are smarter than that. The section of the rotor where the electricity

enters the rotor windings is called the commutator. The electricity is carried between the

rotorand the stator by conductive graphite-copper brushes (mounted on the rotor) which

contact rings on stator. Imagine power is supplied:

The motor rotates toward the pole alignment point. Just as the motor would get to this

point, the brushes jump across a gap in the stator rings. Momentum carries the motor forward

over this gap. When the brushes get to the other side of the gap, they contact the stator rings

again and -- the polarity of the voltage is reversed in this set of rings! The motor begins

accelerating again, this time trying to get to the opposite set of poles. (The momentum has

carried the motor past the original pole alignment point.) This continues as the motor rotates.

In most DC motors, several sets of windings or permanent magnets are present to

smooth out the motion. Easy to control speed controlling the speed of a brushed DC motor is

simple. The higher the armature voltage, the faster the rotation. This relationship is linear to

the motor's maximum speed. The maximum armature voltage which corresponds to a motor's

rated speed (these motors are usually given a rated speed and a maximum speed, such as

1750/2000 rpm) are available in certain standard voltages, which roughly increase in

conjunction with horsepower. Thus, the smallest industrial motors are rated 90 VDC and 180

VDC. Larger units are rated at 250 VDC and sometimes higher. Specialty motors for use in

mobile applications are rated 12, 24, or 48 VDC.

Other tiny motors may be rated 5 VDC. Most industrial DC motors will operate

reliably over a speed range of about 20:1 -- down to about 5-7% of base speed. This is much

better performance than the comparable AC motor. This is partly due to the simplicity of

control, but is also partly due to the fact that most industrial DC motors are designed with


variable speed operation in mind, and have added heat dissipation features which allow lower

operating speeds.

Easy to control torque

In a brushed DC motor, torque control is also simple, since output torque is

proportional to current. If you limit the current, you have just limited the torque which the

motor can achieve. This makes this motor ideal for delicate applications such as textile

manufacturing.

Simple, cheap drive design

The result of this design is that variable speed or variable torque electronics are easy

to design and manufacture. Varying the speed of a brushed DC motor requires little more

than a large enough potentiometer. In practice, these have been replaced for all but sub-

fractional horsepower applications by the SCR and PWM drives, which offer relatively

precisely control voltage and current. Common DC drives are available at the low end (up to

2 horsepower) for under US$100 -- and sometimes under US$50 if precision is not important.

Large DC drives are available up to hundreds of horsepower. However, over about 10

horsepower careful consideration should be given to the price/performance tradeoffs with AC

inverter systems, since the AC systems show a price advantage in the larger systems. (But

they may not be capable of the application's performance requirements).

Disadvantages

Expensive to produce

Can't reliably control at lowest speeds

Physically larger

High maintenance

Dust


3.5.2 MAIN PARTS OF DC MOTOR

Armature

A D.C. motor consists of a rectangular coil made of insulated copper wire wound on a

soft iron core. This coil wound on the soft iron core forms the armature. The coil is mounted

on an axle and is placed between the cylindrical concave poles of a magnet.

Commutator

A commutator is used to reverse the direction of flow of current. Commutator is a

copper ring split into two parts C1 and C2. The split rings are insulated form each other and

mounted on the axle of the motor. The two ends of the coil are soldered to these rings. They

rotate along with the coil. Commutator rings are connected to a battery. The wires from the

battery are not connected to the rings but to the brushes which are in contact with the rings.

Fig: 3.12 Commutators

Brushes

Two small strips of carbon, known as brushes press slightly against the two split

rings, and the split rings rotate between the brushes. The carbon brushes are connected to a

D.C. source.


When the coil is powered, a magnetic field is generated around the armature. The left side of

the armature is pushed away from the left magnet and drawn towards the right, causing rotation.

Fig: 3.13 Brushes

When the coil turns through 900, the brushes lose contact with the commutator and the

current stops flowing through the coil. However the coil keeps turning because of its own

momentum. Now when the coil turns through 1800, the sides get interchanged. As a result the

commutator ring C1 is now in contact with brush B2 and commutator ring C2 is in contact

with brush B1. Therefore, the current continues to flow in the same direction.


Fig: 3.14Commutators and Commutator Ring

PARAMETRS OF THE DC MOTRS:

1. Direction of rotation

2. Motor Speed

3. Motor Torque

4. Motor Start and Stop

Direction of Rotation:

A DC Motor has two wires. We can call them the positive terminal and the negative

terminal, although these are pretty much arbitrary names (unlike a battery where these

polarities are vital and not to be mixed!). On a motor, we say that when the + wire is

connected to + terminal on a power source, and the - wire is connected to the - terminal

source on the same power source, the motor rotates clockwise (if you are looking towards the

motor shaft). If you reverse the wire polarities so that each wire is connected to the opposing

power supply terminal, then the motor rotates counter clockwise. Notice this is just an

arbitrary selection and that some motor manufacturers could easily choose the opposing

convention. As long as you know what rotation you get with one polarity, you can always

connect in such a fashion that you get the direction that you want on a per polarity basis.


Fig: 3.15Positive And Negative Counter Clockwise Rotation

DC Motor Rotation vs Polarity:

Facts:

DC Motor rotation has nothing to do with the voltage magnitude or the current

magnitude flowing through the motor.

DC Motor rotation does have to do with the voltage polarity and the direction of

the current flow.

3.5.3 WORKING OF DC MOTOR

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

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

magnetic field to generate rotational motion.


http://encyclobeamia.solarbotics.net/articles/current.html

http://encyclobeamia.solarbotics.net/articles/dc.html



Fig: 3.16Working of dc motor

PRINCIPLE

When a rectangular coil carrying current is placed in a magnetic field, a torque acts on

the coil which rotates it continuously.

When the coil rotates, the shaft attached to it also rotates and thus it is able to do mechanical

work.

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, commentator 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 commentator 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,

driving it to continue rotating.


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).

Fig: 3.17 Peripheral of dc motor

Construction and Working

Fig: 3.18 Construction and working of dc motor


3.5.4 SPEED CONTROL OF DC Motor:

Whereas the voltage polarity controls DC motor rotation, voltage magnitude controls

motor speed. Think of the voltage applied as a facilitator for the strengthening of the

magnetic field. In other words, the higher the voltage, the quicker will the magnetic field

become strong. Remember that a DC motor has an electromagnet and a series of permanent

magnets.

The applied voltage generates a magnetic field on the electromagnet portion. This

electromagnet field is made to oppose the permanent magnet field. If the electromagnet field

is very strong, then both magnetic entities will try to repel each other from one side, as well

as attract each other from the other side. The stronger the induced magnetic field, the quicker

will this separation/attraction will try to take place. As a result, motor speed is directly

proportional to applied voltage.

Fig: 3.19Speed Curve of Dc Motor

Motor Speed Curve:

One aspect to have in mind is that the motor speed is not entirely lineal. Each motor

will have their own voltage/speed curve. One thing I can guarantee from each motor is that at

very low voltages, the motor will simply not move. This is because the magnetic field

strength is not enough to overcome friction. Once friction is overcome, motor speed will start

to increase as voltage increase.The following video shows the concept of speed control and

offers some ideas on how this can be achieved.


Motor Torque:

In the previous segment I kind of described speed as having to do with the strength of

the magnetic field, but this is in reality misleading. Speed has to do with how fast the

magnetic field is built and the attraction/repel forces are installed into the two magnetic

structures. Motor strength, on the other hand, has to do with magnetic field strength. The

stronger the electromagnet attracts the permanent magnet, the more force is exerted on the

motor load.

Per example, imagine a motor trying to lift 10 pounds of weight. This is a force that

when multiplied by a distance (how much from the ground we are lifting the load) results in

WORK. This WORK when exerted through a predetermined amount of time (for how long

we are lifting the weight) gives us power. But whatever power came in, must come out as

energycan not be created or destroyed. So that you know, the power that we are supplying to

the motor is computed by

P = IV

Where P is power, I is motor current and V is motor voltage

Hence, if the voltage (motor speed) is maintained constant, how much load we are moving

must come from the current? As you increase load (or torque requirements) current must also

increase.

Fig: 3.20Motor Torques Loading


Motor Loading

One aspect about DC motors which we must not forget is that loading or increase of

torque cannot be infinite as there is a point in which the motor simply can not move. When

this happens, we call this loading “Stalling Torque”. At the same time this is the maximum

amount of current the motor will see, and it is refer to Stalling Current. Stalling deserves a

full chapter as this is a very important scenario that will define a great deal of the controller to

be used. I promise I will later write a post on stalling and its intricacies.

Motor Start and Stop

You are already well versed on how to control the motor speed, the motor torque and

the motor direction of rotation. But this is all fine and dandy as long as the motor is actually

moving. How about starting it and stopping it? Are these trivial matters? Can we just ignore

them or should we be careful about these aspects as well? You bet we should!Starting a

motor is a very hazardous moment for the system. Since you have an inductance whose

energy storage capacity is basically empty, the motor will first act as an inductor. In a sense,

it should not worry us too much because current cannot change abruptly in an inductor, but

the truth of the matter is that this is one of the instances in which you will see the highest

currents flowing into the motor. The start is not necessarily bad for the motor itself as in fact

the motor can easily take this Inrush Current. The power stage, on the other hand and if not

properly designed for, may take a beating.

Once the motor has started, the motor current will go down from inrush levels to

whatever load the motor is at. Per example, if the motor is moving a few gears, current will

be proportional to that load and according to torque/current curves.

Stopping the motor is not as harsh as starting. In fact, stopping is pretty much a

breeze. What we do need to concern ourselves is with how we want the motor to stop. Do we

want it to coast down as energy is spent in the loop, or do we want the rotor to stop as fast as

possible? If the later is the option, then we need braking. Braking is easily accomplished by


shorting the motor outputs. The reason why the motor stops so fast is because as a short is

applied to the motor terminals, the Back EMF is shorted. Because Back EMF is directly

proportional to speed, making Back EMF = 0, also means making speed = 0.

3.6 MOTORDRIVER CIRCUIT:(H-BRIDGE)

The name "H-Bridge" is derived from the actual shape of the switching circuit which

control the motion of the motor. It is also known as "Full Bridge". Basically there are four

switching elements in the H-Bridge as shown in the figure below.

3.6.1 OPERATING MODES OF H-BRIDGE

Fig: 3.21H-Bridge Connected To a Motor

As you can see in the figure above there are four switching elements named as "High

side left", "High side right", "Low side right", "Low side left". When these switches are

turned on in pairs motor changes its direction accordingly. Like, if we switch on High side

left and Low side right then motor rotate in forward direction, as current flows from Power

supply through the motor coil goes to ground via switch low side right. This is shown in the

figure below.


Fig: 3.22Current Flowing in High Side And Low Side

Similarly, when you switch on low side left and high side right, the current flows in opposite

direction and motor rotates in backward direction. This is the basic working of H-Bridge. We

can also make a small truth table according to the switching of H-Bridge explained above.

Truth Table

High Left High Right Low Left Low Right Description

On Off Off On Motor runs clockwise

Off On On Off Motor runs anti-clockwise

On On Off Off Motor stops or decelerates

Off Off On On Motor stops or decelerates

Table: 3.2 Truth table

CHAPTER-4


SOFTWARE EXPLANATION:

4.1 INTRODUCTION TO KEIL SOFTWARE:

Software’s used are:

*Keil software for c programming

*Express PCB for lay out design

*Express SCH for schematic design

What's New in µVision4?

µVision3 adds many new features to the Editor like Text Templates, Quick Function

Navigation, and Syntax Colouring with brace high lighting Configuration Wizard for dialog

based start-up and debugger setup. µVision3 is fully compatible to µVision4 and can be used

in parallel with µVision4.

What is µVision4?

µVision3 is an IDE (Integrated Development Environment) that helps you write, compile,

and debug embedded programs. It encapsulates the following components:

A project manager.

A make facility.

Tool configuration.

Editor.

A powerful debugger.

To help you get started, several example programs (located in the \C51\Examples, \C251\

Examples, \C166\Examples, and \ARM\...\Examples) are provided.

HELLO is a simple program that prints the string "Hello World" using the Serial

Interface.

MEASURE is a data acquisition system for analog and digital systems.


TRAFFIC is a traffic light controller with the RTX Tiny operating system.

SIEVE is the SIEVE Benchmark.

DHRY is the Dhrystone Benchmark.

WHETS are the Single-Precision Whetstone Benchmark.

Additional example programs not listed here are provided for each device architecture.

Building an Application in µVision4

To build (compile, assemble, and link) an application in µVision4, you must:

1. Select Project - (for example, 166\EXAMPLES\HELLO\HELLO.UV4).

2. Select Project - Rebuild all target files or Build target.

4.2KEIL SOFTWARE TOOL (STEPS):

Click on the Keil vision Icon on Desktop

1. The following fig will appear

2. Click on the Project menu from the title bar

3. Then Click on New Project


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

folder sited in either C:\ or D:\

5. Then Click on save button above.

6. Select the component for u r project. I.e. Atmel……

7. Click on the + Symbol beside of Atmel

8. Select AT89C52 as shown below

9. Then Click on “OK”


10. The Following fig will appear

11. Then Click either YES or NO………mostly “NO”

12. Now your project is ready to USE

13. Now double click on the Target1, you would get another option “Source group 1”

as shown in next page.

14. Click on the file option from menu bar and select “new”

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

clicking on its blue boarder.


16. Now start writing program in either in “C” or “ASM”

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

“C” based program save it with extension “ .C”

18. Now right click on Source group 1 and click on “Add files to Group Source”

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


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

21. Click only one time on option “ADD”

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

23. If the file contains no error, then press Control+F5 simultaneously.

24. The new window is as follows

25. Then Click “OK”

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

shown in fig below


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

28. Now keep Pressing function key “F11” slowly and observe.

29. You are running your program successfully

CHAPTER-5

5.1 CONCLUSION:

The accidents are avoided at places where there is no person managing the railway

crossing gates. Here we use the stepper motor to open and close the gates automatically when

it is rotated clockwise or anticlockwise direction. When the train arrives in a particular

direction the transmitter IR senses and generates appropriate signal, then at the same time the

receiver IR receives the signal and generates an interrupt. When the interrupt is generated the


stepper motor rotates in clockwise direction. When the interrupt ends the stepper motor

rotates in anti-clock wise direction.

BIBILOGRAPHY

The 8051 Micro controller and Embedded Systems

-Muhammad Ali Mazidi

-Janice GillispieMazidi

The 8051 Micro controller Architecture, Programming & Applications

-Kenneth J.Ayala

Fundamentals Of Microprocessors and Micro computers


-B.Ram

Microprocessor Architecture, Programming & Applications

-Ramesh S. Gaonkar

Electronic Components

-D.V. Prasad

Wireless Communications

- Theodore S. Rappaport

Mobile Tele Communications

- William C.Y. Lee

REFRENCES:

www.national.com

www.atmel.com

www.microsoftsearch.com

www.geocities.com


http://www.geocities.com/

http://www.microsoftsearch.com/

http://www.atmel.com/

http://www.national.com/

STUDENT DATA

1. NAME: N.RAKESH

PHONE NO: 9866576918

EMAIL ID: [email protected]

ROLE IN THE PROJECT: PROJECT LEADER

PERMANENT ADDRESS:LIGH-527, PRASANTHI NAGAR, APHB COLONY,

MOULA-ALI, 500040.

2. NAME: V.SANDEEP

PHONE NO: 9494244100


ROLE IN THE PROJECT: INFORMATION GATHERER ABOUT EMBEDDED

SYSTEM CIRCUIT VERIFIER

PERMANENT ADDRESS:LIGH-529, PRASANTHI NAGAR, APHB COLONY, MOULA-ALI, 500040

3. NAME: G.SHIVA

PHONE NO: 9493420053


ROLE IN THE PROJECT: CIRCUIT DESIGNER AND COMPONENT GATHERER

PERMANENT ADDERESS: UPPAL DEPOT.


Date post:	03-Nov-2014
Category:	Documents
Upload:	rohit-kumar
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automatic railway gate

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