1. Lords institute of engineering and technology
Welcome To
Lords institute of engineering and technology
Mechanical Department
Batch

2. Automatic control of railway gate
Mini project on
Automatic control of railway gate

3. What is an embedded system?
II In built
Embedded System =
Computer Inside a Product

4. 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.

5. 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++ ..,

6. 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

7. 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

8. Automotive & Industrial

11. Chapter -2
Micro controller

12. Micro controller
The first micro controller was implemented in by a car company wolves wagons in their cars.
The 1st micro controller (8048) was developed by Intel in 1976.

13. 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

14. 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,…………

15. AT Mega Microcontroller
AT represents the name of the manufacturing company “ATMEL”.
ATMEL
 Advanced Technology Memory End Logic
MEGA
Clock Frequency of the micro controller (1MHz)

16. 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

17. Pin configuration From 1-40 1 Vcc 40 39 Port B Port A 8 9 10 32 ATMEGA
8515
Reset
ICP 31
ALE 30
OC1B
Port D 29 28 17
Port C
XTAL2 18
XTAL1 19
GND 20 21

18. Memories in AT Mega Data Memory  Temporary EEPROM  Permanent
Flash Memory/Programmable Memory  Permanent

19. 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

20. Memory Mapping of Data Memory
$0000
G. P. R
$001F
$0020
I/O Registers
$005F
$0060
SRAM
$025F

21. Register Pairs / Indirect Addressing
R r x pair
R y pair
z pair
R27
R29
R31
R26
R28
R30
$025F
$  R27
$5F  R26
Rah
Ral

22. Status Register
It is an 8 bit Special register where each bit in the register represents a Flag.
Zero
Interrupt
Zero
Negative
Bit Store
Over flow
Sign
Half carry

23. Chapter - 3
IR sensors

24. Working of IR pairs
Power supply
IR transmitter
IR receiver
comparator

25. 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

26. 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.

27. Chapter - 4
Stepper motor

28. Stepper Motor History : Definition : Construction and Operation : Types of Stepper Motor : Real World Stepper Motor

29. Picture of stepper motor

30. Circuit connections

31. Operation principle of stepper motor

32. 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.

33. 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

34. Thank you