remote control dimmer
TRANSCRIPT
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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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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
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- 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
1 Ground (0V) Ground
2 Serial data output pin Data
3 Linear output pin; not connected NC
4 Supply voltage; 5V Vcc
5 Supply voltage; 5V Vcc
6 Ground (0V) Ground
7 Ground (0V) Ground
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
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network that is circuit switched, providing dedicated circuits for communication between end
nodes, such as the public switched telephone network
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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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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.
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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.
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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.
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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.
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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
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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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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
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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)
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5.2 Block Diagram of Remote control Dimmer:
5.2.1 Transmitter
Fig.5.2. Block Diagram of Transmitter
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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.
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5.3.2 TRANSMITTING CIRCUIT
Fig:5.5 Transmitting circuit
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5.3.3 RECEIVING CIRCUIT
Fig:5.6 Receiving circuit
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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
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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
{
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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.
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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