Post on 26-Mar-2015
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