Remote Control Dimmer

7/30/2019 Remote Control Dimmer

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REMOTE CONTROL DIMMER

E.C.E Dept., ALIET. Page 1

CHAPTER-1

INTRODUCTION

1.1 INTRODUCTION:

Computational tools and computational machines were always the attraction of the

technology implementation in the field of automation for industries and domestic products.

The limitations of digital electronics in the implementation of algorithms have almost

vanished, due to the availability of microprocessors and microcontrollers. Today

microcontrollers have become an integral part of all the automation and semi-automation.

The main objective of our project is to study about the ATMEG8 microcontroller and

also its applications, AVR STUDIO software and EMBEDDED C language. The circuit of the

project is designed in such a way to have a interface with the microcontroller and RF module.

The signals from the input are transmitted through the ENCODER to the transmitting RF

module and the signals are received in the receiving section through the reception module.

Here DIP plays a major role in the encoding and in the decoding process. Here the circuit is

provided with 12V and it is regulated to 5V with help of the 7805 voltage regulator, then the

voltage given to the ENCODER and then to the transmitting module and thereby transmitted

in the form of RF signals to the receiver section. Here the AT MEGA8 is used to set the

brightness of the light and it is controlled by the L293D IC and RF module.

The circuit is advantageous since it consumes a low power and also delivers a low

power at the output and used in many automation for domestic purposes.

1.2 OBJECTIVE:

The main objective of the project is to learn about the basic micro controllers, use of

encoders, decoders, voltage regulators. The basic principle involved in it is to know about theinterface of the micro controller with the RF MODULE which is used to prepare a automated

device. The objective of the device is to act as a REMOTE CONTROL DIMMER with the

help of the code which is to be debugged in the AVR studio


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CHAPTER-2

INTRODUCTION TO MICRO CONTROLLERS

2.1 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 watchesand 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.

2.2 MICROCONTROLLER:

A microcontroller (sometimes abbreviated C, or MCU) is a small computer on a

single integrated circuit containing a processor core, memory, and

programmable input/output peripherals. Program memory in the form of NOR flash or OTP

ROM is also often included on chip, as well as a typically small amount of RAM.


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Microcontrollers are designed for embedded applications, in contrast to

the microprocessors used in personal computers or other general purpose applications.

Microcontrollers are used in automatically controlled products and devices, such as

automobile engine control systems, implantable medical devices, remote controls, officemachines, appliances, power tools, toys and other embedded systems. By reducing the size

and cost compared to a design that uses a separate microprocessor, memory, and input/output

devices, microcontrollers make it economical to digitally control even more devices and

processes. Mixed signal microcontrollers are common, integrating analog components needed

to control non-digital electronic systems.

Some microcontrollers may use four-bit words and operate at clock rate frequencies as

low as 4 kHz, for low power consumption (milli watts or microwatts). They will generallyhave the ability to retain functionality while waiting for an event such as a button press or

other interrupt; power consumption while sleeping (CPU clock and most peripherals off) may

be just nano watts, making many of them well suited for long lasting battery applications.

Other microcontrollers may serve performance-critical roles, where they may need to act more

like a digital signal processor (DSP), with higher clock speeds and power consumption.

2.3 Interrupts:

Microcontrollers must provide real time (predictable, though not necessarily fast)

response to events in the embedded system they are controlling. When certain events occur,

an interrupt system can signal the processor to suspend processing the current instruction

sequence and to begin an interrupt service routine (ISR, or "interrupt handler"). The ISR will

perform any processing required based on the source of the interrupt before returning to the

original instruction sequence. Possible interrupt sources are device dependent, and often

include events such as an internal timer overflow, completing an analog to digital conversion,

a logic level change on an input such as from a button being pressed, and data received on a

communication link. Where power consumption is important as in battery operated devices,

interrupts may also wake a microcontroller from a low power sleep state where the processor

is halted until required to do something by a peripheral event.


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2.4 ARCHITECTURE:

Fig.2.1.Block Diagram of ATmega8


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2.4.1 DEVICE ARCHITECTURE :

Flash, EEPROM, and SRAM are all integrated onto a single chip, removing the need

for external memory in most applications. Some devices have a parallel external bus option to

allow adding additional data memory or memory-mapped devices. Almost all devices (exceptthe smallest Tiny AVR chips) have serial interfaces, which can be used to connect larger serial

EEPROMs or flash chips.

2.5 BUS INTERFACE:

The I2C bus is a simple, two-wire connection that can link multiple devices together

and allow them to exchange data. In its simplest form there is one master device that

communicates to multiple slave devices. All devices are connected in parallel to the two wires

of the I2C bus. The two wires are known as SCL and SDA. SCL is the clock line and is

controlled by the master device. SDA is the bi-directional data line. To transfer data, the

master sends out a slave address combined with a one bit read/write flag. If a write is desired,

the master will continue to send data to the addressed slave. If a read is requested, the slave

will respond with data. To coordinate transactions, the SCL and SDA lines are manipulated by

the master and the slave to signal several conditions. These include START, STOP, ACK

(acknowledge) and NAK (no acknowledge). The details of these conditions are handled by the

drivers. The true geeks among you can learn all the details in the links provided at the end ofthese Instruct able

.The electrical requirements are pretty simple. The master and the slaves must use the

same level for Vcc, the grounds must be connected, and the SCL and SDA lines must be

pulled up to Vcc. The value of the pull-up resistors is precisely determined by a calculation

based on the total capacitance on the bus, but practically can be pretty much any value

between 1.8K and 10K. I start with 5.1K and use lower values until it works. This usually isn't

an issue unless you have a lot of devices or long lengths of wire between devices.

The nominal data rate on the I2C bus is 100Kbits/second. Rates of 400Kbits/second,

1Mbits/second, and beyond are possible as well, but aren't supported by the drivers in this

Instructable. All I2C devices will work at 100Kbits/second.


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R

E.C.E Dept., ALIET.

2.6 FEATURES:

High-performance, Lo

Advanced RISC Archi

- 130 Powerful Instr

- 32 x 8 General Pur

- Up to 6 MIPS Thro

- Fully Static Operati

- On-chip 2-cycle M

Nonvolatile Program a

- 8k Bytes of In-Syst

- Optional Boot Cod

- 512K Bytes EEPR

- Programming Lock

- 1K Byte Internal S

Peripheral Features

- On-chip Analog Co

- Programmable Wat

MOTE CONTROL DIMMER

Fig:2.2 Bus interface

w-power AVR 8-bit Microcontroller

tecture

ctions - Most Single Clock Cycle Execution

ose Working Registers

ughput at 16MHz

on

ltiple.

nd Data Memories

m Self-Programmable Flash

Section with Independent Lock Bits

M

for Software Security

AM.

mparator

chdog Timer with Separate On-chip Oscillator

Page 6


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R

E.C.E Dept., ALIET.

- Master/Slave SPI S

- Two 8-bit Timer/C

- One 16-bit Timer/

- Real Time Counter

- Three PWM Chann

- 8-channel ADC in

- 6-channel ADC in

- Byte-oriented Two-

- Programmable Seri

Special Microcontroll

- Power-on Reset an

- Internal Calibrated

- External and Intern

- Five Sleep Modes:

I/O and Packages

- 23 Programmable I

- 28-lead PDIP, 32-l

MOTE CONTROL DIMMER

erial Interface

unters with Separate Prescalar, Compare

ounter with Separate Prescaler, Compare and C

with Separate Oscillator

els

QFP and MLF package

DIP package

wire Serial Interface

al USART

r Features

Programmable Brown-out Detection

RC Oscillator

al Interrupt Sources

Idle, ADC Noise Reduction, Power-save, Powe

Fig.2.3. View Of ATmega8

O Lines

ad TQFP, 32-pad MLF

Page 7

apture mode

-down .


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2.7 MEMORY:

Typically microcontroller programs must fit in the available on-chip program memory,

since it would be costly to provide a system with external, expandable, memory. Compilers

and assemblers are used to convert high-level language and assembler language codes into acompact machine code for storage in the microcontroller's memory. Depending on the device,

the program memory may be permanent, read-only memory that can only be programmed at

the factory, or program memory may be field-alterable flash or erasable read-only memory.

Manufacturers have often produced special versions of their microcontrollers in order

to help the hardware and software development of the target system. Originally these

included EPROM versions that have a "window" on the top of the device through which

program memory can be erased by ultraviolet light, ready for reprogramming after aprogramming ("burn") and test cycle. Since 1998, EPROM versions are rare and have been

replaced by EEPROM and flash, which are easier to use (can be erased electronically) and

cheaper to manufacture.

2.7.1 Program memory:

Program instructions are stored in non-volatile flash memory. Although the MCUs are

8-bit, each instruction takes one or two 16-bit words.

The size of the program memory is usually indicated in the naming of the device itself

(e.g., the ATmega64x line has 64 kb of flash while the ATmega32x line has 32 kb).

There is no provision for off-chip program memory; all code executed by the AVR

core must reside in the on-chip flash. However, this limitation does not apply to the AT94

FPSLIC AVR/FPGA chips.

2.7.2 Internal data memory:

The data address space consists of the register file, I/O registers, and SRAM.


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Table No.2.1 Pin Description

PORT PIN ALTERNATE FUNCTIONS

P1.5 MOSI(Used for In-system programming)

P1.6 MISO(Used for In-system programming)

P1.7 SCK(Used for In-system programming)

2.8.3 Port 2:

Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. 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

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

2.8.4 Port 3:

Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. 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

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.


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Table.No.2.2 Pin Description

2.8.5 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.

2.8.6 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.


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2.8.7 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.

2.8.8 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.

2.8.9 XTAL1:

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

2.8.10 XTAL2:

Output from the inverting oscillator amplifier.

2.9 INSTRUCTION SET: The AVR Instruction Set is more orthogonal than those of most eight-bit microcontrollers, in

particular the 8051 clones and PIC microcontrollers with which AVR competes today. However, it is

not completely regular:

Pointer registers X, Y, and Z have addressing capabilities that are different from

each other.

Register locations R0 to R15 have different addressing capabilities than register

locations R16 to R31.

I/O ports 0 to 31 have different addressing capabilities than I/O ports 32 to 63.

CLR affects flags, while SER does not, even though they are complementary

instructions. CLR set all bits to zero and SER sets them to one. (Note that CLR is


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pseudo-op for EOR R, R; and SER is short for LDI R,$FF. Math operations such as

EOR modify flags while moves/loads/stores/branches such as LDI do not.)

Accessing read-only data stored in the program memory (flash) requires special LPM

instructions; the flash bus is otherwise reserved for instruction memory.

Additionally, some chip-specific differences affect code generation. Code pointers

(including return addresses on the stack) are two bytes long on chips with up to 128 Kbytes of

flash memory, but three bytes long on larger chips; not all chips have hardware multipliers;

chips with over 8 Kbytes of flash have branch and call instructions with longer ranges; and so

forth.

The mostly regular instruction set makes programming it using C (or even Ada)

compilers fairly straightforward. GCC has included AVR support for quite some time, andthat support is widely used. In fact, Atmel solicited input from major developers of compilers

for small microcontrollers, to determine the instruction set features that were most useful in a

compiler for high-level languages.

2.10 PROGRAM EXECUTION:

Atmel's AVRs have a two stage, single level pipeline design. This means the next

machine instruction is fetched as the current one is executing. Most instructions take just one

or two clock cycles, making AVRs relatively fast among the eight-bit microcontrollers.

The AVR processors were designed with the efficient execution of compiled C code in

mind and have several built-in pointers for the task.

AVRs have a large following due to the free and inexpensive development tools

available, including reasonably priced development boards and free development software.

The AVRs are sold under various names that share the same basic core but with different

peripheral and memory combinations. Compatibility between chips in each family is fairly

good, although I/O controller features may vary.


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CHAPTER-3

ON BOARD PERIFERALS

3.1 6F22 9V BATTERY:

Fig.3.1. 9v Battery

A nine-volt battery, the most common of which (and the one referred to here unless

otherwise stated) is designated a PP3 battery, is shaped as a rounded rectangular prism. 9-volt

batteries are commonly used in pocket transistor radios, smoke detectors, carbon monoxide

alarms, guitar effect units, and radio-controlled vehicle controllers. They are also used as

backup power to keep the time in digital clocks and alarm clocks. Nine-volt alkaline batteries

are constructed of six individual 1.5V LR61 cells enclosed in a wrapper. These cells are

slightly smaller than standard LR8D425 AAAA cells and can be used in their place for some

devices, even though they are 3.5 mm shorter.

As of 2007, 9-volt batteries accounted for 4% of alkaline primary battery sales in the

US. In Switzerland as of 2008, 9-volt batteries totalled 2% of primary battery sales and 2% of

secondary battery sales.


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3.1.1 CONNECTORS:

The connector (snap) consists of two connectors: one smaller circular (male) and one

larger, typically either hexagonal or octagonal (female). The connectors on the battery are the

same as on the connector itself; the smaller one connects to the larger one and vice versa. The

same connector is used on most other battery types in the Power Pack (PP) series. The battery

has both terminals on one end. Battery polarization is obvious since mechanical connection is

only possible in one configuration.

A problem with this style of connector is that it is very easy to connect two batteries

together in a short circuit, which quickly discharges both batteries, generating heat and

possibly a fire. The clips on the nine-volt battery can be used to connect several nine-volt

batteries in series to create higher voltage.

3.1.2 Technical specifications:

Inside an alkaline or carbon-zinc 9-volt battery there are six cells, either cylindrical

alkaline or flat carbon-zinc type, connected in series. Some brands use welded tabs internally

to attach to the cells, others press foil strips against the ends of the cells.

Rechargeable NiCd and NiMH batteries have between six and eight 1.2 volt cells.

Lithium versions use three 3.2 V cells - there is a rechargeable lithium polymer version. There

is also a Hybrid NiMH version that has a very low self-discharge rate (85% of capacity after

one year of storage).Formerly, mercury batteries were made in this size. They had higher

capacity than carbon-zinc types, a nominal voltage of 8.4 volts, and very stable voltage output.

Once used in photographic and measuring instruments or long-life applications, they are now

unavailable due to environmental restrictions.

3.1.3 Self discharge:

An alkaline battery that is unused or used with extremely low power consumption

devices (transistor leak current, etc.) can be expected to last approximately for 6 years,

essentially the shelf-life of a new battery.


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3.1.4 Lithium 9V/PP3:

Lithium 9-volt batteries are consumer-replaceable, high energy density batteries

designed to last up to 5 times longer than alkaline 9-volt batteries and up to 10 times longer

than carbon-zinc 9-volt batteries in many applications. In addition, lithium PP3 batteries have

a long shelf life of up to 10 years. Common applications for lithium 9-volt batteries are smoke

and CO (Carbon Monoxide) alarms.

3.2 VOLTAGE REGULATORS:

A voltage regulator is designed to automatically maintain a constant voltage level. A

voltage regulator may be a simple "feed-forward" design or may include negative

feedback control loops. It may use an electro mechanical mechanism, or electronic

components. Depending on the design, it may be used to regulate one or more AC or DC

voltages.

Electronic voltage regulators are found in devices such as computer power

supplies where they stabilize the DC voltages used by the processor and other elements. In

automobile alternators and central power station generator plants, voltage regulators control

the output of the plant. In an electric power distribution system, voltage regulators may be

installed at a substation or along distribution lines so that all customers receive steady voltage

independent of how much power is drawn from the line.

7805 is a voltage regulator integrated circuit. It is a member of 78xx series of fixed

linear voltage regulator ICs. The voltage source in a circuit may have fluctuations and would

not give the fixed voltage output. The voltage regulator IC maintains the output voltage at a

constant value. The xx in 78xx indicates the fixed output voltage it is designed to provide.

7805 provides +5V regulated power supply. Capacitors of suitable values can be connected at

input and output pins depending upon the respective voltage levels. Voltage regulator is a

single chip/package (IC), the 7805 is a positive voltage DC regulator that has only 3 terminals.

They are: Input voltage, Ground, Output Voltage.


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Fig.3.2. Voltage Regulator

3.2.1 GENERAL FEATURES:

Output Current up to 1A

Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V

Thermal Overload Protection

Short Circuit Protection

Output Transistor Safe Operating Area Protection

3.2.2 LM 78XX SERIES VOLTAGE REGULATOR:

The LM 78XXX series of the three terminal regulations is available with several fixed

output voltages making them useful in a wide range of applications. One of these is local on

card regulation. The voltages available allow these regulators to be used in logic systems,

instrumentation and other solid state electronic equipment. Although designed primarily as

fixed voltage regulators, these devices can be used with external components to obtain

adjustable voltages and currents. The LM78XX series is available in aluminum to 3 packages

which will allow over 1.5A load current if adequate heat sinking is provided. Current limiting

is included to limit the peak output current to a safe value. The LM 78XX is available in the

metal 3 leads to 5 and the plastic to 92. For this type, with adequate heat sinking. The

regulator can deliver 100mA output current.


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The advantage of this type of regulator is, it is easy to use and minimize the number of

external components.

The following are the features voltage regulators:

a) Output current in excess of 1.5A for 78 and 78L series

b) Internal thermal overload protection

c) No external components required

d) Output transistor sage area protection

e) Internal short circuit current limit.

f) Available in aluminum 3 package.

3.2.3 POSITIVE VOLTAGE REGULATOR:

The positive voltage regulator has different features like

Output current up to 1.5A

No external components

Internal thermal overload protection

High power dissipation capability

Internal short-circuit current limiting

Output transistor safe area compensation

Direct replacements for Fairchild microA7800 series


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Table.No.3.1: Electrical absolute ratings

3.3 HT12E Encoder

The HT12E Encoder ICs are series of CMOS LSIs for Remote Control system

applications. They are capable of Encoding 12 bit of information which consists of N addressbits and 12-N data bits. Each address/data input is externally trinary programmable if bonded

out.

Features Encoder

18 PIN DIP

Operating Voltage : 2.4V ~ 12V

Low Power and High Noise Immunity

CMOS Technology

Low Standby Current and Minimum Transmission Word

Built-in Oscillator needs only 5% Resistor

Easy Interface with and RF or an Infrared transmission medium

Minimal External Components

Nominal

Output Voltage

Regulator

5V uA7805C

6V uA7806C

8V uA7808C

8.5V uA7885C

10V uA7810C

12V uA7812C

15V uA7815C


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Block Diagram

HT12E:

Fig.3.3.Block Diagram Of Encoder

Fig.3.4. Pin Diagram Of Encoder


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Table.no.3.2 Pin Description


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3.4 HT12D Decoder

The HT12D Decoder ICs are series of CMOS LSIs for remote control system

applications. This ICs are paired with each other. For proper operation a pair of

encoder/decoder with the same number of address and data format should be selected. TheDecoder receive the serial address and data from its corresponding encoder, transmitted by a

carrier using an RF transmission medium and gives output to the output pins after processing

the data.

Features - Decoder

18 PIN DIP

Operating Voltage : 2.4V ~ 12.0V

Low Power and High Noise Immunity

CMOS Technology

Low Stand by Current

Ternary address setting

Capable of Decoding 12 bits of Information

8 ~ 12 Address Pins and 0 ~ 4 Data Pins

Received Data are checked 2 times, Built in Oscillator needs only 5% resistor

VT goes high during a valid transmission

Easy Interface with an RF of IR transmission medium

Minimal External Components


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Block Diagram:

HT12D

Fig.3.5. Block Diagram Of Decoder

Fig.3.6.Pin Diagram of HT12D


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Table.No.3.3 Pin Description

Applications

Burglar Alarm, Smoke Alarm, Fire Alarm, Car Alarm, Security System

Garage Door and Car Door Controllers

Cordless telephone

Other Remote Control System


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3.5 IC L293D

The L293 and L293D are quad push-pull drivers capable of delivering output currents

to 1A or 600mA per channel respectively. Each channel is controlled by a TTL-compatible

logic input and each pair of drivers a full bridge) is equipped with an inhibit input which turns

off all four transistors. A separate supply input is provided for the logic so that it maybe run

off a lower voltage to reduce dissipation.

Additionally the L293D includes the output clamping diodes within the IC for

complete interfacing with inductive loads.

Both devices are available in 16-pin Batwing DIP packages. They are also available in

Power S0IC and Hermetic DIL packages.

Fig:3.7 IC L293D

Features

Output Current 1A Per Channel (600mAfor L293D)

Peak Output Current 2A Per Channel(1.2A for L293D)

Inhibit Facility

High Noise Immunity

Separate Logic Supply

Over-Temperature Protection


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Block Diagram:

L293D

Fig.3.8.Block Diagram Of L293D

Fig.3.9.Pin Diagram Of L293D


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3.6 RF Module:

RF Modules are used wireless transfer data. This makes them most suitable for remote

control applications, as in where you need to control some machines or robots without getting

in touch with them (may be due to various reasons like safety, etc). Now depending upon the

type of application, the RF module is chosen. For short range wireless control applications, an

ASK RF Transmitter-Receiver Module of frequency 315 MHz or 433 MHz is most suitable.

Fig.3.10. Block Diagram Of RF Section

General RF communication block diagram is shown above. Since most of the

encoders/decoders/microcontrollers are TTL compatible, most of the inputs by the user will be

given in TTL logic level. Thus, this TTL input is to be converted into serial data input using

an encoder or a microcontroller. This serial data can be directly read using the RF Transmitter,

which then performs ASK (in some cases FSK) modulation on it and transmit the data through

the antenna.


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3.6.1 RF TRANSMITING MODULE:

Fig.3.11.Block Diagram Of Transmitting Section

The transmitter/receiver (Tx/Rx) pair operates at a frequency of 434 MHz. An RF

transmitter receives serial data and transmits it wirelessly through RF through its antenna

connected at pin4. The transmission occurs at the rate of 1Kbps - 10Kbps.The transmitted data

is received by an RF receiver operating at the same frequency as that of the transmitter

Fig: 3.12 Pin Diagram Of Transmitting Section


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Table:3.3 Pin Description

3.6.2 RF RECEIVING MODULE

Fig.3.13.Block Diagram Of Receiving Section

In the receiver side, the RF Receiver receives the modulated signal through the

antenna, performs all kinds of processing, filtering, demodulation, etc and gives out a serial

data. This serial data is then converted to a TTL level logic data, which is the same data that

the user has input

Pin NoFunction Name

1 Ground (0V) Ground

2 Serial data input pin Data

3 Supply voltage; 5V Vcc

4 Antenna output pin ANT


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Fig.3.13.1. Pin Diagram Of RF Receiving Module


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Table:3.4 Pin Description

Pin No Function Name


2 Serial data output pin Data

3 Linear output pin; not connected NC





8 Antenna input pin ANT

Overview

The STR-433 is ideal for short-range remote control applications where cost is a

primary concern. The receiver module requires no external RF components except for the

antenna. It generates virtually no emissions, making FCC and ETSI approvals easy. The

super-regenerative design exhibits exceptional sensitivity at a very low cost. The

manufacturing-friendly SIP style package and low-cost make the STR-433 suitable for high

volume applications

Features

Low Cost

5V operation

3.5mA current drain

No External Parts are required

Receiver Frequency: 433.92 MHZ

Typical sensitivity: -105dBm

IF Frequency: 1MHz


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Applications

Car security system

Sensor reporting

Automation system

Remote Keyless Entry (RKE)

Remote Lighting Controls

On-Site Paging

Asset Tracking

Wireless Alarm and Security Systems

Long Range RFI

Automated Resource Management

Specification:

Operating Voltage 4.5 to .5.0

Operating Current - 3.5 to 4.5

Reception Bandwidth- 1.0

Center Frequency - 433.92

Sensitivity -105

Operating Temperature -10 to +60 C

Operation

Super-Regenerative AM Detection

The STR-433 uses a super-regenerative AM detector to demodulate the incoming AM

carrier. A super regenerative detector is a gain stage with positive feedback greater than unity

so that it oscillates. An RC-time constant is included in the gain stage so that when the gain

stage oscillates, the gain will be lowered over time proportional to the RC time constant until

the oscillation eventually dies. When the oscillation dies, the current draw of the gain stage


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decreases, charging the RC circuit, increasing the gain, and ultimately the oscillation starts

again. In this way, the oscillation of the gain stage is turned on and off at a rate set by the RC

time constant. This rate is chosen to be super-audible but much lower than the main oscillation

rate. Detection is accomplished by measuring the emitter current of the gain stage. Any RF

input signal at the frequency of the main oscillation will aid the main oscillation in restarting.

If the amplitude of the RF input increases, the main oscillation will stay on for a longer period

of time, and the emitter current will be higher. Therefore, we can detect the original base-band

signal by simply low-pass filtering the emitter current.

The average emitter current is not very linear as a function of the RF input level. It

exhibits a 1/ln response because of the exponentially rising nature of oscillator start-up. The

steep slope of a logarithm near zero results in high sensitivity to small input signals.

Data Slicer

The data slicer converts the base-band analog signal from the super-regenerative

detector to aTTL compatible output. Because the data slicer is AC coupled to the audio output,

there is a minimum data rate. AC coupling also limits the minimum and maximum pulse

width. Typically, data is encoded on the transmit side using pulse-width modulation (PWM)

or non-return-to-zero (NRZ).

The most common source for NRZ data is from a UART embedded in a micro-

controller. Applications that use NRZ data encoding typically involve microcontrollers. The

most common source for PWM data is from a remote control IC such as the HC-12E from

Holtek or ST14 CODEC from Sunrom Technologies. Data is sent as a constant rate square-

wave. The duty cycle of that square wave will generally be either 33% (a zero) or 66% (a

one). The data slicer on the STR-433 is optimized for use with PWM encoded data, though it

will work with NRZ data if certain encoding rules are followed.

Power Supply

The STR-433 is designed to operate from a 5V power supply. It is crucial that this

power supply be very quiet. The power supply should be bypassed using a 0.1uF low-ESR

ceramic capacitor and a 4.7uF tantalum capacitor. These capacitors should be placed as close


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to the power pins as possible. The STR-433 is designed for continuous duty operation. From

the time power is applied, it can take up to750mSec for the data output to become valid.

Antenna Input

It will support most antenna types, including printed antennas integrated directly onto

the PCB and simple single core wire of about 17cm. The performance of the different

antennas varies. Any time a trace is longer than 1/8th the wavelength of the frequency it is

carrying, it should be a 50 ohm microstrip

3.7 DIODE 1N4007

Fig:3.14 Diode

Features

Diffused Junction

High Current Capability and Low Forward Voltage Drop

Surge Overload Rating to 30A Peak

Low Reverse Leakage

Case: DO-41

Case Material: Molded Plastic. UL Flammability Classification

Moisture Sensitivity: Level 1 per J-STD-020

Terminals: Finish - Bright Tin. Plated Leads

Polarity: Cathode Band

Mounting Position: Any

Marking: Type Number

Weight: 0.30 grams (approximate)


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3.8 Dual Inline Package:

Fig:3.15 Dual Inline Package

3.8.1 DESCRIPTION:

The MM74HC595 high-speed shift register utilizes advanced silicon-gate CMOS

technology. This device possesses the high noise immunity and low power consumption of

standard CMOS integrated circuits, as well as the ability to drive 15 LS-TTL loads.

This device contains an eight-bit serial-in, parallel-out, shift register that feeds an

eight-bit D-type storage register. The storage register has eight 3-state outputs. Separate

clocks are provided for both the shift register and the storage register. The shift register has a

direct over riding clear, serial input, and serial output(standard) pins for cascading. Both the

shift register and storage register use positive-edge triggered clocks. If both clocks are

connected together, the shift register state is one clock pulse ahead of the storage register. The

74HC logic family is speed, function, and pin-out compatible with the standard 74LS logic

family. All inputs are protected from damage due to static discharge by internal diode clamps

to VCC and ground.

3.8.2 Features

Low Quiescent current: 80 A Maximum

(74HC Series)

Low Input Current: 1 A Maximum

8-Bit Serial-In, Parallel-Out Shift Register with


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Storage

Wide Operating Voltage Range: 2V6V

Cascadable

Shift Register has Direct Clear

Guaranteed Shift Frequency: DC to 30MHz

3.9 LED:

It is a semiconductor diode having radioactive recombination. It requires a definite

amount of energy to generate an electron hole pair. The same energy is released when an

electron recombines with a hole. This released energy may result in the emission of photon

and such a recombination. Hear the amount of energy released when the electro reverts from

the conduction band to the valence band appears in the form of radiation. Alternatively the

released energy may result in a series of photons causing lattice libration. Finally the released

energy may be transferred to another electron. The recombination radiation may be lie in the

infra-red and visible light spectrum. In forward is peaked around the band gap energy and the

phenomenon is called injection luminescence. In a junction biased in the avalanche break

down region , there results a spectrum of photons carrying much higher energies . Almost

White light then gets emitted from micro plasma breakdown region in silicon junction. Diodes

having radioactive recombination are termed as Light Emitting Diode, abbreviated as LEDs.

In gallium arsenide diode, recombination is predominantly a radiation recombination

and the probability of this radioactive recombination far exceeds that in either germanium or

silicon . Hence GaAs LED has much higher efficiency in terms of Photons emitted per carrier.

The internal efficiency of GaAs LED may be very close to 100% but because of high index of

refraction, only a small fraction of the internal radiation can usually come out of the device

surface. In spite of this low efficiency of actually radiated light, these LEDs are efficiency

used as light emitters in visual display units and in optically coupled circuits, The efficiency

of light generation increases with the increase of injected current and with decreases in

temperature. The light so generated is concentrated near the junction since most of the charge

carriers are obtained within one diffusion length of the diode junction.


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Fig.3.16. Circuit Diagram of LED

The following are the merits of LEDs over conventional incandescent and other types of

lamps

Low working voltages and currents

Less power consumption

Very fast action

Emission of monochromatic light

Small size and weight

No effect of mechanical vibrations

Extremely long life

3.10 Transformer:

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


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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 turns 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.3.17.An Electrical Transformer

Turns ratio = Vp/ VS = Np/NS

Power Out= Power In

VS X IS=VP X IP

Vp =primary (input) voltage

Np =number of turns on primary coil

Ip = primary (input) current


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RESISTORS:

Fig:3.18 Resistors

A resistor is a passive two-terminal electrical component that implements electrical

resistance as a circuit element.

The current through a resistor is in direct proportion to the voltage across the resistor's

terminals. This relationship is represented by Ohm's law:

where I is the current through the conductor in units of amperes, V is the potential

difference measured across the conductor in units of volts, and R is the resistance of the

conductor in units of ohms.

The ratio of the voltage applied across a resistor's terminals to the intensity of current

in the circuit is called its resistance, and this can be assumed to be a constant (independent of

the voltage) for ordinary resistors working within their ratings.

Resistors are common elements of electrical networks and electronic circuits and areubiquitous in electronic equipment. Practical resistors can be made of various compounds and

films, as well as resistance wire (wire made of a high-resistivity alloy, such as nickel-chrome).

Resistors are also implemented within integrated circuits, particularly analog devices, and can

also be integrated into hybrid and printed circuits.


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The electrical functionality of a resistor is specified by its resistance: common

commercial resistors are manufactured over a range of more than nine orders of magnitude.

When specifying that resistance in an electronic design, the required precision of the

resistance may require attention to the manufacturing tolerance of the chosen resistor,

according to its specific application. The temperature coefficient of the resistance may also be

of concern in some precision applications. Practical resistors are also specified as having a

maximum power rating which must exceed the anticipated power dissipation of that resistor in

a particular circuit: this is mainly of concern in power electronics applications. Resistors with

higher power ratings are physically larger and may require heat sinks. In a high-voltage

circuit, attention must sometimes be paid to the rated maximum working voltage of the

resistor.

3.12 CAPACITORS:

A capacitor (originally known as condenser) is a passive two-terminal electrical

component used to store energy in an electric field. The forms of practical capacitors vary

widely, but all contain at least two electrical conductors separated by a dielectric (insulator);

for example, one common construction consists of metal foils separated by a thin layer of

insulating film. Capacitors are widely used as parts of electrical circuits in many common

electrical devices.

When there is a potential difference (voltage) across the conductors, a static electric

field develops across the dielectric, causing positive charge to collect on one plate and

negative charge on the other plate. Energy is stored in the electrostatic field. An ideal

capacitor is characterized by a single constant value, capacitance, measured in farads. This is

the ratio of the electric charge on each conductor to the potential difference between them.

The capacitance is greatest when there is a narrow separation between large areas of

conductor, hence capacitor conductors are often called "plates," referring to an early means ofconstruction. In practice, the dielectric between the plates passes a small amount of leakage

current and also has an electric field strength limit, resulting in a breakdown voltage, while the

conductors and leads introduce an undesired inductance and resistance.


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Capacitors are widely used in electronic circuits for blocking direct current while

allowing alternating current to pass, in filter networks, for smoothing the output of power

supplies, in the resonant circuits that tune radios to particular frequencies, in electric power

transmission systems for stabilizing voltage and power flow, and for many other purposes.

Fig:3.19 Types of capacitors

3.13 ELECTRONIC SWITCHES:

A relay is an electrically operated switch. Many relays use an electromagnet to operate

a switching mechanism mechanically, but other operating principles are also used. Solid-state

relays control power circuits with no moving parts, instead using a semiconductor device to

perform switchingoften a silicon-controlled rectifier or triac.

The analogue switch uses two MOSFET transistors in a transmission gate arrangement

as a switch that works much like a relay, with some advantages and several limitations

compared to an electromechanical relay.


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The power transistor(s) in a switching voltage regulator, such as a power supply unit,

are used like a switch to alternately let power flow and block power from flowing.

3.20Various types of tactile switches

Many people use metonymy to call a variety of devices "switches" that conceptually

connect or disconnect signals and communication paths between electrical devices, analogous

to the way mechanical switches connect and disconnect paths for electrons to flow between

two conductors. Early telephone systems used an automatically operated Strowger switch to

connect telephone callers; telephone exchanges contain one or more crossbar switches today.

3.20.1 Dip switch

Since the advent of digital logic in the 1950s, the term switch has spread to a variety of

digital active devices such as transistors and logic gates whose function is to change their output

state between two logic levels or connect different signal lines, and even computers, network

switches, whose function is to provide connections between different ports in a computer

network.[12] The term 'switched' is also applied to telecommunications networks, and signifies a


43/65



network that is circuit switched, providing dedicated circuits for communication between end

nodes, such as the public switched telephone network


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R

E.C.E Dept., ALIET.

4.1 INTRODUCTION

AVR Studio is a Dev

AVR Studio enables the user

Emulator or on the built-in A

execution of Assembly progr

and C programs compiled

microcontrollers. AVR Studio

4.2DESCRIPTION:

AVR Studio enables

the built-in AVR Instruction

it must first be compiled wi

Assembler to generate an obje

4.3 AVR STUDIO WIN

4.3.1 Source window:

The Source window is

an object file is opened, and i

the session is terminated.

MOTE CONTROL DIMMER

CHAPTER 4

AVR STUDIO

O AVR STUDIO:

lopment Tool for the AT90S Series of AVR

to fully control execution of programs on the

R Instruction Set Simulator. AVR Studio sup

ams assembled with the Atmel Corporation's

with IAR Systems ICCA90 C Compile

runs under Microsoft Windows95 and Microso

xecution of AVR programs on an AVR In-Ci

et Simulator. In order to execute a program us

h IAR Systems' C Compiler or assembled wi

ct file which can be read by AVR Studio.

OW:

the main window in an AVR Studio session. I

s present throughout the session. If the Source

Figure 4.1 Source Window 1

Page 44

microcontrollers.

T90S In-Circuit

orts source level

AVR Assembler

for the AVR

t Windows NT.

cuit Emulator or

ing AVR Studio,

th Atmel's AVR

is created when

window is close,


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R

E.C.E Dept., ALIET.

The next instruction t

moved by the user, this next

becomes red. A breakpoint i

statement where the breakpoi

Fig

4.3.2 Watch window:

The Watch window

variables in a C program.

information, this window can

An example of a Watch wind

The Watch window has three

watched. The next is the type

MOTE CONTROL DIMMER

be executed is always marked by AVR Studi

tatement can still be identified since the previo

s identified in the Source window as a dot t

t is set. An example of a Source window is giv

re 4.2 Source window 2

an display the types and values of symbols

Since the AVR Assembler does not gener

only be used in a meaningful way when execu

w is given below.

fields. The first field is the name of the symb

of the symbol, and the third is the value of the s

Page 45

. If the marker is

usly marked text

o the left of the

n below.

like for instance

ate any symbol

ting C programs.

l which is being

ymbol.


46/65

R

E.C.E Dept., ALIET.

4.3.3 Register window:

The Register window d

An example of the Register w

When the Register wi

the shape of the window.

The values in the Reg

order to change the contents

the cursor on the register tomake sure to make a pause be

4.3.4 Message window:

The Message window

command is issued, the con

Message window is given bel

The contents in the M

toggled off and then on again.

MOTE CONTROL DIMMER

isplays the contents of the 32 registers in the

indow is given below.

Figure 4.3 Register window

ndow is resized, the contents is reorganized in

ister window can be changed when the executi

f a register, first make sure the execution is sto

change, press the left mouse button twice (noween the mouse button clicks).

displays messages from AVR Studio to the us

tents of the Message window are cleared.

w.

ssage window is remembered also when the M

Only one Message window can be active at a ti

Page 46

VR register file.

order to best fit

on is stopped. In

pped. Then place

t a double click,

r. When a Reset

n example of a

ssage window is

me.


47/65

R

E.C.E Dept., ALIET.

4.3.5 Memory window:

The Memory windo

various memories present in

memory types. The Memory

I/O memory and EEPROM m

The user can have se

window is shown below.

Which Memory type

left of the Memory window.

default memory type. AVR S

placed, but also which mem

Window.

MOTE CONTROL DIMMER

enables the user to inspect and modify the

the execution target. The same window is

window can be used to view Data memory, P

mory.

eral concurrent Memory windows. An exam

o view can be changed in the memory selecti

When a new Memory window is created, Dat

udio not only keeps track over where the Mem

ry type it is displaying, and also the formatt

Figure 4.4 Memory window

Page 47

contents of the

sed to view all

rogram memory,

le of a Memory

n box at the top

a memory is the

ory windows are

ing status of the


48/65



4.3.6 Processor window:

The Processor window contains vital information about the execution target. An

example of a Processor window is shown below.

Figure 4.5 Processor window

4.3.7 Peripheral Device windows:

The user can watch the contents of the I/O in the Memory window. Viewing the

I/O area as a flat memory structure is not a very convenient way of observing the status of themany I/O devices of the microcontroller in question. Specialized Device windows have

therefore been incorporated to ease the observation of I/O devices.

4.3.8 Commands:

AVR Studio incorporates a number of different commands. The commands can be

given in various ways: through menu selections, toolbar buttons and by keyboard shortcuts.

4.3.9 Execution Target:

AVR Studio can be targeted towards an AVR In-Circuit Emulator or the built-in AVR

Simulator. When the user opens a file, AVR Studio automatically detects whether an Emulator

is present and available on one of the systems serial ports. If an Emulator is found, it is


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R

E.C.E Dept., ALIET.

selected as the execution targ

AVR Simulator instead.

The Status bar will i

Emulator or the built-in AVR

4.4 Shortcut summary:

4.5 Embedded C:

Embedded C is a set o

Standards committee to addr

different embedded systems.

extensions to the C language i

multiple distinct memory ban

In 2008, the C Standar

providing a common standar

features not available in norm

basic I/O hardware addressin

MOTE CONTROL DIMMER

t. If no Emulator is found, execution will be do

ndicate whether execution is targeted at the

Simulator.

Figure 4.6 summary

f language extensions for the C Programming l

ess commonality issues that exist between

Historically, embedded C programming requ

n order to support exotic features such as fixed

s, and basic I/O operations.

s Committee extended the C language to addre

for all implementations to adhere to. It inclu

al C, such as, fixed-point arithmetic, named ad

.

Page 49

ne on the built-in

AVR In-Circuit

nguage by the C

extensions for

ires nonstandard

point arithmetic,

s these issues by

des a number of

ress spaces, and


50/65



Embedded C use most of the syntax and semantics of standard C, e.g., main () function,

variable definition, data type declaration, conditional statements (if, switch. case), loops

(while, for), functions, arrays and strings, structures and union, bit operations, macros, etc.

As assembly language programs are specific to a processor, assembly language didntoffer portability across systems. To overcome this disadvantage, several high level languages,

including C, came up. Some other languages like PLM, Modula-2, Pascal, etc. also came but

couldnt find wide acceptance. Amongst those, C got wide acceptance for not only embedded

systems, but also for desktop applications. Even though C might have lost its sheen as

mainstream language for general purpose applications, it still is having a strong-hold in

embedded programming. Due to the wide acceptance ofC in the embedded systems, various

kinds of support tools like compilers & cross-compilers, ICE, etc. came up and all this

facilitated development ofembedded systems using C.


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CHAPTER-5

CIRCUIT ANALYSIS

5.1 BLOCK DIAGRAMS:

5.1.1 BLOCK DIAGRAM OF POWER SUPPLY:

Figure 5.1 Power supply block diagram

A power supply may be implemented as a discrete, stand-alone device or as an integral

device that is hardwired to its load. Examples of the latter case include the low voltage DC

power supplies that are part of desktop computers and consumer electronics devices.The basic

circuit diagram of a regulated power supply (DC O/P) with led connected as load.

The components mainly used in above figure are

230V AC MAINS

TRANSFORMER

BRIDGE RECTIFIER(DIODES)

CAPACITOR

VOLTAGE REGULATOR(IC 7805)

RESISTOR

LED(LIGHT EMITTING DIODE)


52/65



5.2 Block Diagram of Remote control Dimmer:

5.2.1 Transmitter

Fig.5.2. Block Diagram of Transmitter


53/65



5.2.2 Block Diagram Of Receiver

Fig.5.3. Block Diagram Of Receiver


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5.3 CIRCUIT DIAGRAM

5.3.1 POWER SUPPLY CIRCUIT DIAGRAM:

Figure5.4 Power Supply Circuit Diagram

Transformers are used to transform the primary to secondary windings which help to

step up or step down the voltage. In the circuit above we have used a step down transformer

which decreases the voltage from 230V to 12V. Then the signal is passed through the rectifier,

which converts one form of energy into another form. Rectifier is of two types full wave and

a half wave. After rectification the unwanted signal is removed using a filter. The voltage

regulator maintains the output voltage at a constant value. 7805 provides +5V regulated power

supply. Capacitors of suitable values can be connected at input and output pins dependingupon the respective voltage levels. By this the output voltage is maintained to 5V.


55/65



5.3.2 TRANSMITTING CIRCUIT

Fig:5.5 Transmitting circuit


56/65



5.3.3 RECEIVING CIRCUIT

Fig:5.6 Receiving circuit


57/65



5.4 OPERATION:

The entire circuit is supplied with 12 volts it is done by using a step down transformer

connected to the mains supply. The 12 volts supply is then regulated to 5 volts with a 7805

voltage regulator .The 5v output is given to the HT12 E encoder it will encodes the given databy using DIP and I is given to the RF transmitting module. The RF module transmits the

given data to the RF receiver. It will receives and gives the output to the HT12D decoder. It

will decodes the given data and sends it to the microcontroller . The micro controller gives the

output to the L293D which acts like an H-bridge circuit. The output from the L293D is given

to the LED.

The code is debugged in the AVR studio software with EMBEDDED C language and

is dumped in the micro controller. The sequence of steps which are used in the code are based

on the EMBEDDED C language.

The RF module will transmits the signals in the form of RF waves in to the space. For

the correct reception we are using the DIP . DIP maintains a code value and it receives only

the data from the respected transmitting section by using the code.

By using the transmitter we can adjust the Intensity of the light. We can increase the

intensity of light (or) we can decrease the intensity of light.

The code is written in such a way that at the intensity may increase or decrease

according to the operations given from the transmitter (or) remote.


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5.5 PROGRAM CODE

CODE:

/* REMOTE CONTROL DIMMER

Active low switches

PD0- decrease the intensity of light

PD3- increase the intensity of light

PD4- Indication of the decreased intensity

PD5- Indication of the increased intensity

PD6- IR sensor output

*/

#ifndef sbi

#define sbi(ADDRESS,BIT) (ADDRESS|=1


59/65



OCR1A = 200;

TCCR1A = 0x82;

TCCR1B = 0x19; //Fast PWM

}

void main()

{

DDRD=0x00;

DDRC=0x00;

DDRB=0xFF;

//init_timer1();

PORTD=0xFF;

PORTB=0xFF;

PORTC=0x00;

_delay_ms(1000);

while(1)

{

PORTB=0x00;

If(!rbi(PIND,0))

decrease_the_light intensity();if(!rbi(PIND,3))

increase_the_light intensity();

}

}

void decrease_the_light intensity()

{

while(rbi(PINC,4))

{

if(rbi(PINC,0))

PORTB=0x01;

else

{


60/65



while(rbi(PINC,5))

PORTB=0x02;

break;

}

}

}

void increase_the_light intensity ()

{

while(rbi(PINC,5))

PORTB=0x02;

}


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CHAPTER 6

RESULT ANALYSIS

6.1 Results:


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6.2 Applications:

Industries:

Many people use RF solutions for monitoring, process, control, inventory

tracking, data links and bar code reading devices.

Commercial wireless applications:

Such as door announcers, security and access systems, gate control,

remote activation, score board and paging systems.

Automotive companies:

Many of them employ RF for wireless remote control, remote keyless

entry and safety applications.

Consumer products:

Including electronic toys, home security, gate and garage door openers,intercom, fire and safety systems and irrigation controllers

Medical products :Patient call and monitoring, handicap assistance device, surgery

communication system, remote patient data logging and ECG monitor

6.3 Advantages

Speed and direction control from remote place

Speed level and direction display on LCD Reliable and Easy to operate

Scopes for Advancement:

Tachometer can be developed to measure the speed using reed switch

6.4 Disadvantages

Initial cost is high

It gets affected by climatic disturbances


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CHAPTER 7

CONCLUSION:

It is an automated device since the RF transmission and reception is handled by the

micro controller the entire code for this operation of the micro controller is debugged in the

AVR studio software and also here we have learnt regarding the Micro Controller ATMEGA8

working and its applications .Here we have used the encoders, decoders and also the voltage

regulators .The interface between the Micro controller and RF module is learnt i.e. I2C bus

interface made between this two components was learnt and also observed in the circuit. The

language which was used for the coding of the program in the Micro Controller is Embedded

C. It was learnt and also the code was dumped in the micro controller.


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CHAPTER 8

FUTURE SCOPE & FURTHER DEVELOPMENTS

ADDING A CAMERA:

For the purpose of security system cameras is being used at the shutter openers.

ZIGBEE MODULE:

Zigbee module is replaced in place of RF module for long distance transmission or

large coverage area.

HIGH VOLATGE DC MOTORS:

In order to meet the practical applications high voltage dc motors is being used.


65/65


CHAPTER 9

BIBILOGRAPHY

1. Mastering serial communications-Peter- W. Gafton.2. An Embedded Software Primer David E. Simon.

3. Introduction to Embedded Systems Raj Kamal.

4. www.atmel.com

5. www.stepperworld.com

6. www.engineergarage.com

7. www.nationalsemiconductor.com

8. www.datasheetachieved.com

Documents

Remote Control Dimmer