WelcomeTo

Lords institute of engineering and technology

Mechanical DepartmentBatch 2006-10

Mini project on

Automatic control of railway gate

Embedded System = Computer Inside a Product

II In built

Embedded System

Embedded system is combination of hardware & software for specific application.

Embedded system means the processor is embedded into that application.

An embedded product uses a microprocessor or microcontroller to do one task only.

In an embedded system, there is only one application software that is typically burned into ROM.

How an embedded system works..?

It works with the help of both the hardware and software requirements

Hardware: processor, memories, peripherals, power supply etc..,

Software: assembly language program (ALP) like c, c++ ..,

Types of embedded systems

Simple embedded system

ex: small electrical equipments completes its work with in the approximated time

Complex embedded system

ex: used in military missiles for target based system

Examples of embedded systems

• Electronic devices in the kitchen

E.g.: bread machines, food processors,

microwave ovens

• Living Rooms

E.g.: televisions, stereos, remote controls

• Work places

E.g.: fax, pagers, laser printers, cash

registers, credit card readers

Automotive & Industrial

Chapter -2

Micro controller

Micro controller

The first micro controller was implemented in 1968 by a car company wolves wagons in their cars.

The 1st micro controller (8048) was developed by Intel in 1976.

Found in 1984.

Corporate headquarters located in San Jose, California.

AVR basic architecture was developed by two students

‘Alf- Egil Bogen’and ‘Vegard Wollan’ at the Norwegian

Institute of Technology.

IP Core was sold to Atmel by Alf and Vegard

ATMEL AT89C, AT90S, AT Mega, ATCAN

AT Mega AT Mega 8 , AT Mega 8515

AT Mega 8535, AT Mega 16

AT Mega 32, AT Mega 162,…………

AT Mega Microcontroller

AT represents the name of the manufacturing company “ATMEL”.

ATMEL

Advanced Technology Memory End Logic

MEGAClock Frequency of the micro controller (1MHz)

Features of ATMega8515

40 Pin IC, PDIP package High-performance, Low-power AVR 8-bit Microcontroller RISC Architecture 130 Powerful Instructions – Most Single Clock Cycle

Execution 32 x 8 General Purpose Working Registers Program and Data Memories 8K Bytes of In-System Self-programmable Flash 512 Bytes EEPROM Endurance: 100,000 Write/Erase Cycles 512 Bytes Internal SRAM 35 Programmable I/O Lines

Pin configuration From 1-40

ATMEGA

8515

Port A

Port B

Port C

Port D

Reset

XTAL2

XTAL1

GND

Vcc

OC1B

ALE

ICP

401

8

9

10

1718

1920 21

2829

30

31

32

39

Memories in AT Mega

Data Memory Temporary

EEPROM Permanent

Flash Memory/Programmable Memory Permanent

Data Memory

General Purpose Registers (G.P.R)

32 registers R0 to R31

Each 8 bits

I/O Registers 64 Each 8 bits

SRAM 512 bytes

Memory Mapping of Data Memory

$0000 G. P. R

I/O Registers

SRAM

$001F

$0020

$005F

$0060

$025F

Register Pairs / Indirect Addressing

R r x pair R y pair z pair

R27

R29

R31

R26

R28

R30

RalRah

$025F

$02 R27$5F R26

Status Register

It is an 8 bit Special register where each bit in the register represents a Flag.

Interrupt

Bit Stor

eHalf carr

y

SignOver flow

Negative Zero

Zero

Chapter - 3

IR sensors

Working of IR pairs

Power supply

IR transmitter

IR receivercomparato

r

DETECTION FACTORS:

Six factors typically affect the Probability of Detection (Pd) of most area surveillance (volumetric) sensors, although to varying degrees.

These are the: 1) Amount and pattern of emitted energy; 2) Size of the object; 3) Distance to the object; 4) Speed of the object; 5) Direction of movement

SENSORS APPLICATIONS:

Most sensors have been designed with a specific application in mind.

The environment categorizes these applications where they are most commonly employed.

The two basic environments or categories are exterior and interior.

Each of the two basic categories has a number of sub-sets, such as fence, door, window, hallway, and room.

The first two of the following set of graphics show a “FREE TREE” illustration of the sensors most applicable to the these two environments.

Chapter - 4

Stepper motor

Stepper Motor History :

Definition :

Construction and Operation :

Types of Stepper Motor :

Real World Stepper Motor

Picture of stepper motor

Circuit connections

Operation principle of stepper motor

PRECAUTION If the stepper motor moves slightly and/or queers hack and

forth, there are a number of possible causes. If you are using a battery power supply, the batteries may be too

weak to power the motor properly. Note; Batteries wear out quickly because the current draw from

stepper motors is usually high. If you substituted another transistor for the TIP120 NPN

transistor, the substitute transistor may not be switching properly or the current load of the stepper motor may be too great. Solution; use TIPO120 transistors.

You have the stepper motor improperly wired into the circuit. Check the coils using an ohmmeter and rewire if necessary.

The pulse frequency is too high. If the pulses to the stepper moor are going faster that the motor can react, the motor will malfunction.

Conclusion

This is to conclude that this project Automatic control of railway gate is useful to know when the train is passes through the gate, and to close or open the gate automatically as the train is about to reach the gate. Through which accidents can be avoided as people tend to cross the track in spite the gate is being closed