Wireless Radio Frequency Module Using PIC Microcontroller.

Wireless RF Module
Using PIC Controller Six Weeks Summer Training Report

PIC16F72/73 Microcontroller

An RF module is a small electronic circuit used to transmit, receive, or transceive
radio waves on one of a number of carrier frequencies. RF modules are widely used
in consumer applications such as garage door openers, wireless alarm systems, indus-
trial remote controls, smart sensor applications, weather monitoring system, RFID,
wireless mouse technology and wireless home automation systems. They are often
used instead of infrared remote controls as they have the advantage of not requir-
ing line-of-sight operation.

Project By Abhi Sharma

ABSTRACT
The Radio Frequency Module is basically a PIC Microcontroller Based Wireless
Communication System. Wireless RF Module Technology enables a vast edge to any
electronics project & provide many consistent advantages, which leads it to today’s
up-to-date technology. An RF module is a small electronic circuit used to transmit,
receive, or transceive a radio waves on one of a number of carrier frequencies. RF
modules are widely used in consumer applications such as garage door openers,
wireless alarm systems, industrial remote controls, smart sensor applications and
wireless home automation systems. They are often used instead of infrared remote
controls as they have the advantage of not requiring line-of-sight operation.
Radio Frequency involves two sub units Named, Transmitter & Receiver. As their
name implies transmitter is used to transmit or to send the data from input & it
convert into serial port data by using HT12E encoder. This encoded data get re-
ceived by receiver placing far away from it. The first job that a receiver do after
receiving it, Is to convert or decode the data into parallel ports by using HT12D de-
coder. After converting the data into parallel form we simply connect the receiver
side circuit with relay so that we can operate AC devices (e.g. Bulb, Tube, Fan etc.)
with RF Module.
And, About The Matter Technology that I have used is PIC16F73. The Technology
of Any Project is Considered as The Heart as well as The Mind To It. The Biggest
Concern To Any Student Or Trainee Remains That The Technology He’s Going Learn
Must Be Up-to-Date and Must to be In Industry’s Interest. So, That’s Why I’ve Chosen
PIC Series Of Microcontrollers. They are Cost Effective, Provide Wide Availability,
large user base, extensive collection of application notes, availability of low cost
or free development tools, and serial programming (and re-programming with
flash memory) capability.
The very first thing that concern to any electronics engineering student before
choosing the project is it’s Applications. That means How much innovative the proj-
ect is ? And How We can make it more innovative & also make it up-to-date so that
it can extend to the bigger Applications of this age of Smart & Vast life.? And, Also
It’s Applications must be cost effective so that everyone can use it without any
economical hesitation. There are numerous applications of wireless RF module. As,
Today’s one of the vast & leading technology Named RFID is based on this principle
of RF module. The wireless mouse also work on the same principle. And, beyond
them Industrial Automation, Custom Wireless Remote Controls like wireless x-ray
systems & Long-Range Wireless Switch System (Hand-Held), Machine To Machine
(M2M) RF Wireless Networking, Robot Control , Weather Monitoring System &
Identifying Objects Using RF Transmitters And Receivers and Retrieving Data Using
GSM etc. could be considered as It’s Future prospects to work on. This is Indeed a
great Project to work on.!

ii

Acknowledgement
It would be inappropriate to call this report complete and successful, If I don’t
thank the people who guided as in the preparation of this project. The submis-
sion of this project report gives me an opportunity to convey my gratitude to all
those who have helped me to reach stage from where I have immense confidence to
launch my career in the competitive world of electronics engineering.
First and foremost, I would like to acknowledge my hearty thanks to the respected
Mr. |------------|, HOD (ECE) for being a source of perpetual inspiration and for
providing me such a nice environment for training with timely help.
I would also like to express my most sincere gratitude and indebtedness to my
guide Mr. |-------------| for their valuable help during the development of this
project. Without his priceless suggestion and timely help I would not be able to
complete this project. He has been a source of perpetual inspiration to me, towards
a bright career. Not to forget the pain staking efforts of my college training and
placement cell. Last but not the least I would express my utmost regards for the
electronics and communication department of my Institute.

ABHISHEK SHARMA
B-TECH.
ECE - 4TH SEM.

Contact Me

iii

List Of Tables & Figures Used

Tables Page No.
Fig: 6.6.2 Feature Table Of PIC16F73 27

Fig: 9.3 Frequencies Table Of RF 39

Figures
Fig: 4.1.1 Types Of OrCAD 8

Fig: 4.3.1 A Still Of MikroC 12

Fig: 5.3.4 The Procedure Of PCB Designing Using
OrCAD 16

Fig: 5.4.2 Designing a Circuit In Capture CIS 18

Fig: 5.5.3 Designing a PCB Footprint in
Layout Plus 20
Fig: 6.0 Various PIC Microcontrollers Offered By
Microchip 21
Fig: 6.6 Pin Diagram Of PIC16F73 24

Fig: 6.8 Flowchart Of PIC & It’s Core Architecture 28
Fig: 6.9.1 Voltage-Frequency Graph Of PIC 29
Fig: 9.3.1 RF Frequency Spectrum 40
Fig: 9.5 Block Diagram Of RF Operation 40
Fig: 9.5.1 Transmitter/Receiver Explained 41
Fig: 9.8 RF Module 45
Fig: 9.9.1 Operation Of Serial Encoder 46
Fig: 9.9.2 Operation Of Serial Decoder 47
Fig: 9.10 Flowchart Of RF Module 48
Fig: 11.1.1 RFID 51
Fig: 11.2.4 Wireless RF Based Mouse 53
Fig: 11.5 M2M PIC Tail Daughter Board 55
Fig: 11.6 Flowchart Of RF Based Control Robot 56
iv

Table Of Content
Chapter No. Title Page No.

Title Page i

Abstract ii

Acknowledgement iii

List Of Tables & Figures iv

1. Introduction 1

1.1 What is Wireless.? 1
1.2 Examples Of Wireless
Devices 2
1.3 Radio Frequency 2
1.4 What is RF Module ? 2
1.5 RF Module’s Performance 2
1.6 Scope of Wireless RF Module 3

2. Features Of RF Module 4

3. Hardware & Software
5
Requirements
3.1 Input Requirement 5
3.2 Output Requirement 5
3.3 Software Requirement 6
3.4 Hardware Requirement 6

4. Tools To be Used 7
4.1 OrCAD 8
4.1.1 PCB Designing 8
4.1.2 Layout Plus 9
4.1.3 Capture CIS 9
4.2 PIC Burner 10

4.3 MikroC 11
4.4 USB PIC Bootloader 13

5. PCB Designing 14

5.1 Types Of PCB 14
5.2 Function Of PCB 14
5.3 Techniques Used 15
5.4 OrCAD Design Environment 17
5.5 Placement Of Layout Plus 19

6. Technology To be Used 21
6.1 Introduction 22
6.2 Special Microcontroller
22
Features
6.3 Peripheral Features 23
6.4 CMOS Technology 23
6.5 Data Space (RAM) 23
6.6 PIN Diagram 24
6.6.1 PIN Description 25
6.6.2 Feature Table 27
6.7 Memory Orgenization 27
6.8 Core Architecture 28
6.9 USART 29

7. Project Planning 30
7.1 Project Planning & Scheduling 30

8. Requirement Analysis 31
8.1 Listing The Components
8.1.1 Components 32
8.1.2 PCB 32
8.1.3 Capacitor 32
8.1.4 L.E.D 33
8.1.5 L.C.D 33
8.1.6 Relay 34
8.1.7 Resistor 34
8.1.8 BX433A 35
8.1.9 ULN280 1A 35
8.1.10 Battery 35
8.1.11 HT12E/ Encoder 36
8.1.12 HT12D/ Decoder 36
8.1.13 PIC16F73 37

9. Working Of RF Module 38
9.1 Special Properties Of RF Current 38
9.2 Frequency Chart 39
9.3 RF Module Interfacing With PIC 40
9.4 Block Diagram & Explanation 40
9.5 Source Code For PIC 43
9.6 Serial Encoder/Decoder 44
9.7 Operational Working Of RF 45
9.8 Ckt Implementation 46
9.8.1 Transmitter Section 46
9.8.2 Receiver Section 47
9.9 Working Flowchart 48

10. What is Hex File Format.? 49
10.1 Structure Of Hex File Format 49

11. Applications Of RF Module 50
11.1 RFID 50
11.1.1 Operation Of RFID 50
11.1.2 Applications Of RFID 51
11.2 Wireless Mouse 52
11.2.1 RF Transmitter 52
11.2.2 RF Receiver 52
11.2.3 RF Frequency 52
11.2.4 Advantages 53
11.3 Industrial Automation 53
11.4 Custom Wireless Remote Controls 54
11.4.1 Wireless X-Ray System 54
11.4.2 Long Range Transmitter 54
11.5 Machine to Machine Wireless RF
55
Networking
11.6 Robot Using RF Remote Control 56

12. Actual PCB Photographs 57

13. Future Of Project 59
13.1 Identifying Objects 59
Using RF Technology
13.2 Radio Transmitter Design 59
13.3 Two Channels RF Control 60
13.4 Weather Monitoring System 60
14. Appendix 61

15. Bibliography 62

1. INTRODUCTION
1.1 What is wireless ?
Wireless is a term used to describe telecommunications in which
electromagnetic waves (rather than some form of wire) carry the
signal over part or all of the communication path. Some monitoring
devices, such as intrusion alarms, employ acoustic waves at fre-
quencies above the range of human hearing; these are also some-
times classified as wireless.

Wireless technology is rapidly evolving, and is playing an increasing
role in the lives of people throughout the world. In addition, ever-
larger numbers of people are relying on the technology directly or
indirectly. (It has been suggested that wireless is overused in some
situations, creating a social nuisance.)

1.2 Examples Of Wireless
Devices
• Cellular phones and pagers -- provide connectivity for
portable and mobile applications, both personal and business
• Global Positioning System (GPS) -- allows drivers of cars and
trucks, captains of boats and ships, and pilots of aircraft to as
certain their location anywhere on earth
• Cordless computer peripherals -- the cordless mouse is a
common example; keyboards and printers can also be linked
to a computer via wireless
• Cordless telephone sets -- these are limited-range devices,
not to be confused with cell phones
• Home-entertainment-system control boxes -- the VCR
control and the TV channel control are the most common
examples; some hi-fi sound systems and FM broadcast
Receivers also use this technology
• Remote garage-door openers -- one of the oldest wireless
Devices in common use by consumers; usually operates at
Radio frequencies
• Two-way radios -- this includes Amateur and Citizens Radio
Service, as well as business, marine, and military
Communications
• Baby monitors -- these devices are simplified radio
transmitter/receiver units with limited range
• Satellite television -- allows viewers in almost any location to
select from hundreds of channels.

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1.3 Radio Frequency
Radio Frequency (RF) is a rate of oscillation in the range of about 3
kHz to 300 GHz, which corresponds to the frequency of radio waves,
and the alternating currents which carry radio signals. It is the use
of radio signals to communicate real-time data from the warehouse
floor to the WMS database and back to the floor.

This expedites processing in the warehouse. Scanners collect the data
and transmit it via radio frequency to antennas located throughout
the warehouse.

From the antennas, the signal proceeds to an access point that com-
municates with the warehouse management system. This process
reduces paper, data entry time delays, cycle count processing, out of
stock quantities, typing errors, and misshipments.

1.4 What is RF Module?
An RF Module is a (usually) small electronic circuit used to transmit,
receive, or transceive radio waves on one of a number of carrier fre-
quencies. RF Modules are widely used in consumer application such
as garage door openers, wireless alarm systems, industrial remote
controls, smart sensor applications, and wireless home automation
systems. They are often used instead of infrared remote controls as
they have the advantage of not requiring line-of-sight operation.

1.5 Main Factor Affecting RF Module’s
Performance
As with any other radio-frequency device, the performance of an RF
Module will depend on a number of factors. For example, by increas-
ing the transmitter power, a larger communication distance will be
achieved. However, this will also result in a higher electrical power
drain on the transmitter device, which will cause shorter operating life
for battery powered devices.

Also, using a higher transmit power will make the system more prone
to interference with other RF devices, and may in fact possibly cause
the device to become illegal depending on the jurisdiction.

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1.6 Typical Applications/Scope of
Wireless RF Module
• Vehicle Monitoring
• Remote Control
• Telemetry
• Small-Range wireless network
• Wireless meter reading
• Access control systems
• Wireless home security systems
• Area paging
• Industrial data acquisition system
• Radio tags reading
• RF contact less smart cards
• Wireless data terminals
• Wireless fire protection systems
• Biological signal acquisition
• Hydrological and meteorological monitoring
• Robot remote control
• Wireless data transmissions
• Digital video/audio transmission
• Digital home automation, such as remote light
• Industrial remote control and remote sensing
• Remote control for household appliances and
Electronics projects
• Mobile web server for elderly people monitoring

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2. FEATURES Of RF MoDULE
There are several features of wireless RF Module:
• Interference Immunity
• Low Power Required
• Receiver Sensitivity
• RF Basics
• Wireless Data Communication
• Wireless Transceiver Modules
• Reliable
• Power Efficient
• Long Range Communication
• 3KHz - 300GHz of Range
• Cost Effective
• Small size (QLP 4x4 mm package)
• True single chip UHF RF transmitter
• Frequency bands: 300-348 MHz,
400-464MHz and 800-928 MHz
• Programmable data rate up to 500kBaud
• Low current consumption
• Programmable output power up to
+10dBm for all supported frequencies
• Programmable baseband modulator
• Ideal for multi-channel operation
The RF Transmitter and Receiver modules provide • Very few external components:
a simple to use RF data link at up to 300GHz from • Completely on-chip frequency
any standard CMOS/TTL source. The modules are Synthesizer,
very simple to operate and offers low current con- • no external filters needed
sumption. Data can be supplied directly from a • Configurable packet handling hardware
microprocessor or encoding device, thus keeping • Suitable for frequency hopping systems
the component count down and ensuring a low due to a fast settling frequency
hardware cost. These modules exhibit extremely synthesizer
stable electronic characteristics due to the use of • Optional Forward Error Correction with
Etched The PCB In OrCAD Technology, which uses interleaving
no adjustable components and ensures very • Many powerful digital features allow a
reliable operation. high-performance RF system to be made
using an inexpensive microcontroller
• Efficient SPI interface: All registers can
be programmed with one “burst”
transfer
• Integrated analog temperature sensor
• Support for asynchronous transparent
transmit mode for backwards
compatibility with existing radio
communication protocols

Page 4

3. HARDWARE & SOFTWARE
REQUIREMENTS

3.1 Input Requirements
The Wireless RF Module has following Input Requirements:

• The CPU Must Has 8-Pin Port So that The Serial Port Can Be Inserted
for Burning Purposes.

• If We have a Laptop Then Universal USB To Serial Port Converter
Could be Used For Burning.

• PIC IC is Most Important For Input The Source Code in It.

• Mikro C is Also used as Input Required Software.

• Any kind of sensors are also usable as input requirement.

3.2 Output Requirements
For Getting the output we can use any hardware devices as follows. It
all depends upon our programming requirements. As:

• LCD Can be used To Receive The Output of the PIC.

• LED or 7-Segments offers the Same properties as of LCD.

• DC Motor or Stepper Motors or Relays are also used as output
Requirement devices.

• We can also use PS/2 keyboards & ADC Ports etc.

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3.3 Software Requirements
• Windows , LINUX as an operating system.

• OrCAD as work space for PCB designing.

• TINA PRO for Simulation Purposes.

• Mikro C as a Compiler for Embedded C.

• PIC Burner.

• Boot Loader.

3.4 Hardware Requirements
• Pentium 4 Computer(Atleast).

• 256 MB RAM.

• Software Interfacing with PIC 16F73 Kit.

• Universal USB to Serial Port Convertor Using Laptop.

• 8-Pin serial port for burning the IC using CPU.

• Keyboard.

• Hard disk (20 GB).

• Mouse.

Page 6

4. Tools Used For
Development

OrCAD is a proprietary software tool suite used primarily for electronic design automation.
The software is used mainly by electronic design engineers and electronic technicians to
create electronic schematics and electronic prints for manufacturing printed circuit boards.
The name OrCAD is a portmanteau, reflecting the company and its software's origins:
Oregon + CAD

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4.1 OrCAD
The Cadence OrCAD product line provides affordable, high-performance PCB design
tools that boost productivity for smaller design teams and individual PCB designers.

4.1.1 PCB Designing

PCB stands for “PRINTED CIRCUIT BOARD”. Printed circuit board (PCB) provides
both the physical structure for mounting and holding the components as well as
the electrical interconnection between the components. That means a PCB or
PWB (printed wiring board) is the platform upon which electronic components
such as integrated circuit chips and other components are mounted. A PCB con-
sists of a nonconducting substrate (typically fibre glass with epoxy as resin) upon
which the conductive pattern or circuitry is formed. Copper is the most prevalent
conductor although nickel, silver and tin are also used in some cases.

Fig: 4.1.1 Types Of OrCAD
OrCad has a long history of providing individuals and teams with a complete set
of technologies that offer unprecedented productivity, seamless tool integration,
and exceptional value. New 10.5 release continues that tradition.
Today's lower cost and yet highly sophisticated electronic design automation
systems have created a unique challenge to nearly every engineering department.
Therefore the use of EDA tools has become increasingly important as product life
cycles have become shorter and shorter.

Modern electronic design automation (EDA) tools are beginning to support a
more efficient and integrated approach to electronic. OrCad Capture® design
entry is the most widely used schematic entry system in electronic design today
for one simple reason: fast and universal design entry. Whether you're designing a
new analog circuit, revising schematic diagram for an existing PCB, or designing a
digital block diagram with an HDL module, OrCad Capture provides simple sche-
matic commands you need to enter, modify and verify the design for PCB. OrCad
Layout ® offers PCB designers and PCB design teams the power and flexibility to
create and share PCB data and constraints across the design flow. OrCad Layout
delivers all the capabilities to designers need from netlist to place and route, to
final output.

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4.1.2 Layout Plus
Shrinking design cycles and a growing number of nets with constraints require cus-
tomers to adopt PCB design methodologies that increase predictability and acceler-
ate design turnaround. Cadence® layout and routing technology offers a scalable,
easy-to-use, constraint-driven PCB design solution for simple to complex PCBs,
including those with RF etch components.

Cadence® OrCAD® PCB Designer contains a fully integrated design flow that in-
cludes a constraint manager, design capture technology, component tools, a PCB
editor, an auto/interactive router, and interfaces for manufacturing and mechanical
CAD.

At the heart of OrCAD PCB Designer is OrCAD PCB Editor, an interactive environ-
ment for creating and editing simple to complex multi-layer PCBs. The extensive
feature set addresses a wide range of design and manufacturability challenges.
OrCAD PCB Designer and OrCAD PCB Designer with PSpice both include Cadence
SPECCTRA® for OrCAD, the market-leading PCB solution for automatic and interac-
tive interconnect routing.

Features
Offers a proven, scalable, easy-to-use PCB editing and routing solution that grows
as needed
Tight, front-to-back application integration increases productivity and ensures data
integrity
A comprehensive feature set and a seamless PCB design environment delivers a
complete solution to take a design from concept to production

4.1.3 Capture CIS
OrCAD Capture provides fast and intuitive schematic design entry for PCB develop-
ment or analog simulation using PSpice. The component information system (CIS)
integrates with it to automatically synchronize and validate externally sourced part
data.
Easy-to-use and powerful, Cadence® OrCAD® Capture is the most widely used
schematic design solution, supporting both flat and hierarchal designs from the
simplest to the most complex. Seamless bidirectional integration with OrCAD PCB
Editor enables data synchronization and cross-probing/placing between the sche-
matic and the board design. OrCAD Capture allows designers to back annotate lay-
out changes, make gate/pin swaps, and change component names or values from
board design to schematic using the feedback process. It also comes with a large
library of schematic symbols and can export net lists in a wide variety of formats.

Page 9

CIS allows designers to search, identify, and populate the design with preferred
parts. With easy access to company component databases and part information,
designers can reduce the amount of time spent researching needed parts.

Features
• Boosts schematic editing efficiency of complex designs through hierarchical and
Variant design capabilities.

• Integrates with a robust CIS that promotes the use of preferred, current parts to
Accelerate the design process and reduce project costs.

• Provides access to more than two million parts with Cadence Active Parts,
Offering greater flexibility when choosing design components.

4.2 PIC Burner
This is the ultimate PIC/EEPROM programmer! The internet is full of PIC program-
mer software. The problem is that most of the programmers support only one type
of hardware and only one operating system.

PIC Burner is very versatile software. We can use different kinds of hardware with it,
because the pins used on parallel port can be set using a simple ini-file. We can also
use different assemblers, because pburn can read all kinds of Intel hex file formats
used (inhx32, inhx16 and inhx8m).

Features
• Linux and Windows XP/Vista/7 support

• Parallel port hardware support

• Program memory and configuration memory read/write/verify

• Data memory read/write/verify

• Reads and writes multiple hex file formats (inhx32, inhx16, inhx8m)

• Input file format auto detection

• Good documentation

• Support for serial port hardware
Page 10

4.3 Mikro C (Compiler)

4.3.1 Introduction To MikroC
MikroC is a powerful, feature rich development tool for PICmicros. It is designed
to provide the programmer with the easiest possible solution for developing ap-
plications for embedded systems, without compromising performance or control.
PIC and C fit together well: PIC is the most popular 8-bit chip in the world, used
in a wide variety of applications, and C, prized for its efficiency, is the natural
choice for developing embedded systems. mikroC provides a successful match
featuring highly advanced IDE, ANSI compliant compiler, broad set of hardware
libraries, comprehensive documentation, and plenty of ready-to-run examples.

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Fig: 4.3.1 A Still Of MikroC

Features
mikroC allows you to quickly develop and deploy complex applications:

• Write your C source code using the built-in Code Editor (Code and Parameter
Assistants, Syntax Highlighting, Auto Correct, Code Templates, and more…)
• Use the included mikroC libraries to dramatically speed up the development: data
Acquisition, memory, displays, conversions, communications
• Monitor your program structure, variables, and functions in the Code Explorer.

• Generate commented, human-readable assembly, and standard HEX compatible
with all programmers.
• Inspect program flow and debug executable logic with the integrated Debugger.

• Get detailed reports and graphs: RAM and ROM map, code statistics, assembly
Listing, calling tree, and more…
• We have provided plenty of examples for you to expand, develop, and use as
Building bricks in your projects. Copy them entirely if you deem fit

4.3.2 Projects
mikroC organizes applications into projects, consisting of a single project file (extension
.ppc) and one or more source files (extension .c). You can compile source files only if they
are part of a project.
The project file carries the following information:

• project name and optional description,
• target device,
• device flags (config word),
• device clock,
Page 12

4.4 USB PIC Bootloader
(PIC-BOOT)
A bootloader is a program that stays in the micro controller and communicates with the
PC (usually through the serial interface).The bootloader receives a user program from
the PC and writes it in the flash memory, then launches this program in execution.
Bootloaders can only be used with those micro controllers that can write their flash
memory through software as PIC16F870.
USB PIC Bootloader is a resident bootloader for PIC18 series of Enhanced Flash USB
Micro controllers. It allows us to program a new firmware application image into the chip
using the standard USB connectivity of your device.

• USB PIC Bootloader fully complies with USB Specification for Human Input Devices
(HID) and all interfacing is done via standard HID driver from Microsoft.
• XTEA encryption algorithm is used to protect privacy of firmware application updated
With USB PIC Bootloader.
• USB PIC Bootloader code is write-protected and cannot be overwritten by firmware.

• Firmware update or user mode is selected by SW and/or HW switch.

• USB PIC Bootloader is a small program that stays in the first 2,048 bytes of the pro
Gram memory of the Microchip PIC Micro controller.
• Bootloader runs at the boot time (when the processor has just been reset) and is
Capable of loading a complete application program into a processor's memory.
• With the USB PIC Bootloader loaded, there are two distinct modes of operation:
Firmware update mode and user mode.
• USB PIC Bootloader uses the EEPROM mark and/or hardware switch to determine
which mode to run in.

The bootloader firmware is given in the form of Basic source program that has to be
compiled with PIC Simulator IDE integrated Basic compiler to get the HEX file ready to be
programmed into the microcontroller. The correct micro controller model needs to be
selected - 16F877(A), and the selected clock frequency is supposed to be at least 8MHz

Since the start address 0000 hex is set for the boot loader software our New start is
always 0010 hex. This means that when we write our code must always think that the
start is at address 0010 hex.

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5. PCB Designing
PCB stands for “PRINTED CIRCUIT BOARD”. Printed circuit board (PCB) provides
both the physical structure for mounting and holding the components as well as
the electrical interconnection between the components. That means a PCB or PWB
(printed wiring board) is the platform upon which electronic components such as
integrated circuit chips and other components are mounted. A PCB consists of a
non-conducting substrate (typically fiber glass with epoxy as resin) upon which the
conductive pattern or circuitry is formed. Copper is the most prevalent conductor
although nickel, silver and tin are also used in some cases.

5.1 Types of PCB
PCB may be of different types:-

1) Single-sided
2) Double-sided
3) Multilayer

Single sided PCBs: - As the name suggest in these designs the conductive
pattern is only at in one side. And also the size is large in
these case but these are cheap.
Double sided PCBs:-These are the PCBs on which the conductive pattern is in on
both sides. The size of board is small in this case but it
is costlier than that of above.
Multilayer PCBs:- In this case the board consists of alternating layers of
conducting pattern and insulating material. The conductive
Material is connected across the layers through plated
Through holes.
The size of this PCB is smaller than that of double sided PCB but it is very costly.

PCBs may also be either rigid, flexible, or the combination of two (rigid-flex). When
the electronic components have been mounted on the PCB, the combination of
PCB and components is an electronic assembly, also called PRINTED CIRCUIT AS-
SEMBLY. This assembly is the basic building block for all the electronic appliances
such as television, computer and other goods.

5.2 Function Of PCB
Printed circuited boards are dielectric substrates with metallic circuitry formed
on that. They are some times referred to as the base line in electronic packaging.
Electronic packaging is fundamentally an inter connection technology and the PCB
is the baseline building block of this technology.

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5.3 Techniques Used For PCB Designing
There mainly two techniques which are use for the PCB designs.
1. Hand Taping
2. Computer Aided Design

5.3.1 PCBs using Hand Taping
o PCB design using hand taping is the process of technical drawing.
o In hand taping method layout should be prepared on grid paper.
o In hand taping, components pads can be prepared by using black pads.
o Routing of the board can be done by tapes with different widths.
o Each layer (top, bottom) has to prepare separately.

DISADVANTAGES OF HAND-TAPING FOR PCB DESIGNING

o Each layer has to be designed separately.
o We cannot generate NCD files for CNC drilling.
o Difficult to modify the design in the designing process or after designing.
o Difficult to get good design overview.

5.3.2 PCB Designing Using CAD

All the above difficulties can be removed by using CAB system.
CAD system for PCB designing requires following:
o A computer system.
o PCB design software like OrCad, CADSTAR, Protel, TANGO, Mentor etc.
o A photo plotter for art work generation.

There are many enhanced features in electronics design automation tools which not possi-
ble in the hand taping.

The Main Advantages Are Given Below

o Auto placement
o Auto routing
o After routing, optimization of tracks can be done.
o Provides physical design reuse modules
o Electrical rule check (ERC)
o All the layers are generated from the same design by giving different options.
o Bill of material can be generated which contains number of different components
used.
o We can draw conductors as an arc, semi-circular at different angles.
o Design Rule Check
o Advanced CAD systems have high speed analysis.
o CAD system provides all NCD files and Gerber data files for photo plotting.

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5.3.3 Basic Design System In CAD
The following design steps are very common while designing a PCD in CAD:

• Entry the schematic diagram.
• Net list file creation.
• Placement of components manually or automatically.
• Routing of the board using manual routing tools or auto router
• Design rule check physical and electrical.
• Artwork generation.

5.3.4 Traditional Design Flow In
CAD

Fig: 5.3.4 The Procedure Of PCB Designing Using OrCAD

5.3.5 Designing Softwares
There many softwares which are used for PCB designs. Some of them are given below:-
• OrCad
• CADSTAR
• Protel
• TANGO
• Mentor
The most commonly software which are used for PCB design in India are Protel and
OrCad.

Page 16

5.4 OrCAD Design Environment
OrCad has a long history of providing individuals and teams with a complete set of tech-
nologies that offer unprecedented productivity, seamless tool integration, and exceptional
value. New 10.5 release continues that tradition.

Today's lower cost and yet highly sophisticated electronic design automation systems
have created a unique challenge to nearly every engineering department. Therefore the
use of EDA tools has become increasingly important as product life cycles have become
shorter and shorter. Modern electronic design automation (EDA) tools are beginning to
support a more efficient and integrated approach to electronic.

OrCad Capture® design entry is the most widely used schematic entry system in electronic
design today for one simple reason: fast and universal design entry. Whether you're de-
signing a new analog circuit, revising schematic diagram for an existing PCB, or designing
a digital block diagram with an HDL module, OrCad Capture provides simple schematic
commands you need to enter, modify and verify the design for PCB. OrCad Layout ® offers
PCB designers and PCB design teams the power and flexibility to create and share PCB
data and constraints across the design flow.

OrCad Layout delivers all the capabilities to designers need from netlist to place and
route, to final output. The ease-of use and intuitive capabilities of OrCad Layout provides
for quick startup and rapid learning right out of the box.

5.4.1 PCB Design Steps In OrCAD 10.5
Entry of Schematic Diagram
Schematic diagram provides the functional flow and the graphical representation of an
electronic circuit. The entry of schematic diagram is the first step in PCB design using
OrCad.
A schematic diagram consists of:-
• Electrical connections(nets)
• Junctions
• Integrated circuits symbols
• Discrete components symbols like resistors, capacitors etc.
• Input / output connectors
• Power and ground symbols
• Buses
• No connection symbols
• Components reference names
• Text

Page 17

5.4.2 The Schematic Page Editor

The schematic page editor is used to display and edit schematic pages. So that one can
parts; wires; buses and draw graphics. The schematic page editor has a tool palette that
you can use to draw and place everything you need to create a schematic page. One can
print from within the schematic page editor, or from the project window.

Fig: 5.4.2 Designing a Circuit In Capture CIS

5.4.3 The Part Editor
The part editor is used to create and edit parts.
From the view menu of the part editor you can choose either part or package. In part
view one can:-
• Create and edit parts and symbols, then store in new or existing libraries.
• Create and edit power and ground symbols, off-page connector symbols, and title
block
• Use the tool palette’s electrical tools to place pins on parts, and its drawing tools
to draw parts and symbols.

One can search for information in the session log using the find command on the Edit
menu. You can also save the contents of the of the session log to a file, which is useful
when working with OrCAD’s technical support to solve technical problems. The default
filename is SESSION.TXT
Page 18

5.4.4 Creating Net List File
Net-list file is a document file which contains information about the logical interconnec-
tions between signals and pins. Before one create a net list file, be sure one’s project is
completed, annotated and it is free from electrical rule violations.
A net list file consists of nets, components, connectors, junctions, no connection symbol,
power and ground symbols.

Creation of net list in capture:

• Select your design in the project manager.
• From the tools, choose create net list. The net list dialog box displays.
• Choose a net list format tab.
• If necessary, set the part value and PCB foot print combined property strings to
Reflect the information you want in the net list.
• Click OK to create the net list.
• In the net list file text box, enter a name for the output file. If the selected format
creates an additional file, enter its file name in the second text box.

5.5 Placements Of Layout Plus:

5.5.1 What is Layout Plus ?
Layout plus is one part for the PCB design in which we place as well as route the components
an set unit of measurement, grids, and spacing in OrCad. Within other soft wares you also
have to place and route the components in similar way. For the placement and routing of
the components we normally use auto-placement and auto-routing. Unfortunately, in a lot
of soft wares some critical signals have to be routed manually before auto-routing. In layout
plus we also define the layer stacks, pad stacks and via's.

5.5.2 Steps for board design
• At first, we have created a net list from our schematic diagram by using capture.
• Layout plus includes design rules in order to guide logical placement and routing.
That means, load the net list into layout to create the board.
• Specify board parameters: Specifying global setting for the board, including nits of
Measurements, grid, and spacing
• Place components: Use the components tool in order to place manually the
Components which are fixed by the system designer on the board or otherwise use
Auto-placement.
• Route the board: Use different routing technologies to route the board and take
Advantage of push and shove (a routing technology), which moves track you are
Currently routing as well as you can also auto route the board.
• Provide finishing of the board: Layout supplies an ordered progression of
commands on the auto menu for finishing your design. These commands include
design rule check, cleanup design, rename components, back annotate, run post
processor, and create reports.

Page 19

5.5.3 Method To Create a Board With Layout
Plus
• Ensure that net list with all footprints and necessary information has been
created.
• Create a directory in which the schematic design, net list, and boar will co-exit
and put the schematic design and net list. OrCad provides a directory for this
purpose.
• From the layout session frame’s file menu, choose New. The load template file in
the dialog box displayed.

Fig: 5.5.3 Designing a PCB Footprint in Layout Plus

5.5.4 Placement of components:
Placement of components means that to place the components in designed box. A de-
signer should follow the following steps before going for it:-
• Optimize the board for component placement.
• Load the placement strategy file.
• Place components on the board.
• Optimize placement using various placements

Components can be placed by using two techniques:-
1) Manual placement of components
2) Auto placement of components

Choose the components tool bar button. From the pop up men, choose the queue for
placement. The components selection criteria dialog box appears. Enter the reference
designator of the components that you want to place in the appropriate text box, and
Page 20 click ok. Drag the components to desired location, place it there.

6. Technology To Be
Used
The Technology of Any Project is Considered as The Heart as well as The Mind To It.
The Biggest Concern To Any Student Or Trainee Remains That The Technology He’s
Gonna Learn Must Be Up-to-Date and Must to be In Industry’s Interest. So, That’s Why
I’ve Choose PIC Series Of Microcontrollers. They are Cost Effective, Provide Wide Avail-
ability, large user base, extensive collection of application notes, availability of low
cost or free development tools, and serial programming (and re-programming with
flash memory) capability.

Fig: 6 Various PIC Microcontrollers Offered By Microchip
The Microchip 16C84 (PIC16x84), introduced in 1993 , was the first Microchip CPU with on-
chip EEPROM memory. This electrically erasable memory made it cost less than CPUs that
required a quartz “Erase window” for erasing EPROM.
It is generally thought that PIC stands for Peripheral Interface Controller, although General
Instruments' original acronym for the initial PIC1640 and PIC1650 devices was "Programma-
ble Interface Controller". The acronym was quickly replaced with "Programmable Intelligent
Computer".

Page 21

PIC 16 Series-PIC16F73
PIC16F73/76 devices are available only in 28-pin packages,while PIC16F74/77
devices are available in 40-pin and 44-pin packages. All devices in the
PIC16F7X family share common architecture, with the following differences:

• The PIC16F73 and PIC16F76 have one-half of the total on-chip memory of
the PIC16F74 and PIC16F77.
• The 28-pin devices have 3 I/O ports, while the 40/44-pin devices have 5.

• The 28-pin devices have 11 interrupts, while the 40/44-pin devices have 12.

• The 28-pin devices have 5 A/D input channels, while the 40/44-pin devices
have 8.
• The Parallel Slave Port is implemented only on the 40/44-pin devices.

6.1 Introduction
PIC is a family of Harvard architecture microcontrollers made by Microchip
Technology, derived from the PIC1640 originally developed by General Instru-
ment's Microelectronics Division. The name PIC initially referred to
"Peripheral Interface Controller"

PICs are popular with developers and hobbyists alike due to their low cost,
wide availability, large user base, extensive collection of application notes,
availability of low cost or free development tools, and serial programming (and
re-programming with flash memory) capability.

6.2 Special Microcontroller
Features:
• High performance RISC CPU.
• Only 35 single word instructions to learn.
• All single cycle instructions except for program branches which are two-cycle.

1. Operating speed:DC - 20 MHz clock input DC - 200ns instruction cycle.
2. Up to 8K x 14 words of FLASH Program Memory, Up to 368 x 8 bytes
of Data Memory (RAM).
3. Interrupt capability (up to 12 sources).
4. Eight level deep hardware stack.
5. Direct, Indirect and Relative Addressing modes.
6. Processor read access to program memory.
7. Power-on Reset (POR).
8. Power-up Timer (PWRT) and Oscillator Start-up Timer (OST).
9. Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable
operation.
10. Programmable code protection.
11. Power saving SLEEP mode.
12. Selectable oscillator options.
Page 22 13. In-Circuit Serial Programming(ICSP) via two pins.

6.3 Peripheral Features:
a. Timer0: 8-bit timer/counter with 8-bit prescaler.
b. Timer1: 16-bit timer/counter with prescaler, can be incremented during
SLEEP via external crystal/clock.
c. Timer2: 8-bit timer/counter with 8-bit period register, prescaler and post
Scaler.
d. Two Capture, Compare, PWM modules:
i. Capture is 16-bit, max. Resolution is 12.5 ns
ii. Compare is 16-bit, max. Resolution is 200 ns
iii. PWM max. resolution is 10-bit.
e. 8-bit, up to 8-channel Analog-to-Digital converter.
f. Synchronous Serial Port (SSP) with SPI (Master mode) and I2C(Slave).
g. Universal Synchronous Asynchronous Receiver Transmitter (USART/SCI).
h. Parallel Slave Port (PSP), 8-bits wide with external RD, WR and CS controls
(40/44-pin only).
i. Brown-out detection circuitry for Brown-out Reset (BOR).

6.4 CMOS Technology:
a. Low power, high speed CMOS FLASH technology.
b. Fully static design.
c. Wide operating voltage range: 2.0V to 5.5V.
d. High Sink/Source Current: 25 mA.
e. Industrial temperature range.
f. Low power consumption:
i. < 2 mA typical @ 5V, 4 MHz

6.5 Data space (RAM)
PICs have a set of registers that function as general purpose RAM. Special pur-
pose control registers for on-chip hardware resources are also mapped into the
data space. The addressability of memory varies depending on device series, and
all PIC devices have some banking mechanism to extend addressing to additional
memory. Later series of devices feature move instructions which can cover the
whole addressable space, independent of the selected bank. In earlier devices,
any register move had to be achieved via the accumulator.

To implement indirect addressing, a "file select register" (FSR) and "indirect reg-
ister" (INDF) are used. A register number is written to the FSR, after which reads
from or writes to INDF will actually be to or from the register pointed to by FSR.
Later devices extended this concept with post- and pre- increment/decrement for
greater efficiency in accessing sequentially stored data. This also allows FSR to be
treated almost like a stack pointer (SP).

Page 23

6.6 Pin Diagram

Fig: 6.6 Pin Diagram Of PIC16F73

Page 24

6.6.1 Pin Description
(••) MCLR-(pin 1)
PIC16F7X devices have a noise filter in the MCLR Reset path. The filter will
detect and ignore small pulses. It should be noted that a WDT Reset does not
drive MCLR pin low. The behaviour of the ESD protection on the MCLR pin
has been altered from previous devices of this family. Voltages applied to the
pin that exceed its specification can result in both MCLR Resets and excessive
current beyond the device specification during the ESD event. For this reason,
Microchip recommends that the MCLR pin no longer be tied directly to VDD.

(••) RESET
The PIC16F7X differentiates between various kinds of RESET:
• Power-on Reset (POR)
• MCLR Reset during normal operation
• MCLR Reset during SLEEP
• WDT Reset (during normal operation)
• WDT Wake-up (during SLEEP)
• Brown-out Reset (BOR)
Some registers are not affected in any RESET condion. Their status is unknown
on POR and unchanged n any other RESET. Most other registers are reset to a
RESET state” on Power-on Reset (POR), on the MCLR and WDT Reset, on MCLR
Reset during LEEP, and Brown-out Reset (BOR). They are not affected by a WDT
Wake-up, which is viewed as the resumption of normal operation. The TO and
PD bits are set or cleared differently in different RESET situations, as indicated

(••) PORTA –(pin 2 to 7)and the TRISA Register
PORTA is a 6-bit wide, bi-directional port. The corresponding data direction
register is TRISA. Setting a TRISA bit (= ‘1’) will make the corresponding PORTA
pin an input (i.e., Put the corresponding output driver in a Hi-Impedance
mode). Clearing a TRISA bit (= ‘0’) will make the corresponding PORTA pin an
output (i.e., put the contents of the output latch on the selected pin).

Reading the PORTA register reads the status of the pins, whereas writing to it
will write to the port latch. All write operations are read-modify-write opera-
tions. Therefore, a write to a port implies that the port pins are read, the value
is modified and then written to the port data latch.

(••) GND –(pin 8)
Provide Ground to it.

(••) OSC1/CLK IN -(pin 9)
Page 25 Oscillator crystal input/external clock source input.

(••) OSC2/CLK OUT-(pin 10)
Oscillator crystal output. Connects to crystal or resonator in Crystal
Oscillator mode. In RC mode, the OSC2 pin outputs CLK OUT
which has 1/4 the frequency of OSC1, and denotes the instruction
cycle rate.

Oscillator Type:
The PIC16F7X can be operated in four different oscillator modes:
• LP Low Power Crystal
• XT Crystal/Resonator
• HS High Speed Crystal/Resonator
• RC Resistor/Capacitor

(••) PORTC and the TRISC Register(pin 11 to 18)
PORTC is an 8-bit wide, bi-directional port. The corresponding data direction register
is TRISC. Setting a TRISC bit (= ‘1’) will make the corresponding PORTC pin an input
(i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISC
bit (= ‘0’) will
make the corresponding PORTC pin an output (i.e., put the contents of the output
latch on the selected pin).
PORTC is multiplexed with several peripheral functions PORTC pins have Schmitt Trig-
ger input buffers. When enabling peripheral functions, care should be taken in defin-
ing TRIS bits for each PORTC pin.

(••) Vss(pin 19)
Ground reference for logic and I/O pins

(••) Vdd(pin 20)
Positive supply for logic and I/O pins

(••) PORTB and The TRISB Register(pin 21 to 28)
PORTB is an 8-bit wide, bi-directional port. The corresponding data direction register
is TRISB. Setting a TRISB bit (= ‘1’) will make the corresponding PORTB pin an input
(i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISB
bit (= ‘0’) will make the corresponding PORTB pin an output (i.e., Put the contents of
the output latch on the selected pin).
Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on
all the pull-ups. The weak pull-up is automatically turned off when the port pin is
configured as an output. The pull-ups are disabled on a Power-on Reset.

Page 26

6.6.2 Feature Table Of PIC16F73

Fig: 6.6.2 Feature Table Of PIC16F73

6.7 Memory Organization
There are two memory blocks in each of these PICmicro® MCUs. The Program
Memory and Data Memory have separate buses so that concurrent access can
Occur and is detailed in this section. The Program Memory can be read internally
By user code.
Additional information on device memory may be found in the PICmicro Mid-
Page 27 Range Reference Manual.

6.8 Core Architecture

Fig: 6.8 Flowchart Showing a typical microcontroller device and its different sub-Units

The PIC architecture is distinctively minimalist. It is characterized by the follow-
ing features:
• Separate code and data spaces (Harvard architecture)
• A small number of fixed length instructions
• Most instructions are single cycle execution (4 clock cycles), with single
delay cycles upon branches and skips
• A single accumulator (W), the use of which (as source operand) is
implied (i.e. is not encoded in the opcode)
• All RAM locations function as registers as both source and/or destination
of math and other functions.
• A hardware stack for storing return addresses
• A fairly small amount of addressable data space (typically 256 bytes),
Extended through banking
• Data space mapped CPU, port, and peripheral registers
• The program counter is also mapped into the data space and writable
(this is used to implement indirect jumps).

Unlike most other CPUs, there is no distinction between memory space and reg-
ister space because the RAM serves the job of both memory and registers, and
Page 28 the RAM is usually just referred to as the register file or simply as the registers.

Advantages
The PIC architectures have these advantages:
• Small instruction set to learn.
• RISC architecture.
• Built in oscillator with selectable speeds.
• Easy entry level, in circuit programming plus in circuit debugging.
• PICKit units available from Microchip.com for less than $50.
• Inexpensive microcontrollers.
• Wide range of interfaces including I²C, SPI, USB, USART, A/D,
programmable comparators, PWM, LIN, CAN, PSP, and Ethernet.

6.9 Universal Synchronous Asynchronous
Receiver &Transmitter(USART)
The Universal Synchronous Asynchronous Receiver Transmitter (USART)
module is one of the two serial I/O modules. (USART is also known as a
Serial Communications Interface or SCI.) The USART can be configured
as a full duplex asynchronous system that can communicate with pe-
ripheral devices, such as CRT terminals and personal computers, or it
can be configured as a half duplex synchronous system that can commu-
nicate with peripheral devices, such as A/D or D/A integrated
circuits, serial EEPROMs, etc.
The USART can be configured in the following modes
• Asynchronous (full duplex)
• Synchronous - Master (half duplex)
• Synchronous - Slave (half duplex)

Bit SPEN (RCSTA<7>) and bits TRISC<7:6> have to be set in order to config-
ure pins RC6/TX/CK and RC7/RX/DT as the Universal Synchronous Asyn-
chronous Receiver Transmitter.

6.9.1 PIC16F73 Voltage-Frequency Graph

Page 29
Fig: 6.9.1 The V-F Graph Of PIC

7. Project Planning
7.1 Project Planning & Scheduling
The planning stage establishes a bird’s eye view of the intended software product,
and uses this to establish the basic project structure, evaluate feasibility and risks
associated with the project, and describe appropriate management and technical
approaches.
Project planning is part of Project Management. It is a well-established approach
to managing and controlling the introduction of new initiatives or organisational
changes. Projects are finite in length, usually one-time pieces of work involving a
number of activities that must be completed within a given time frame, and often
on a fixed budget.
While the very simplest projects can be managed easily by applying common sense
and just getting on with things, projects that are more complex need a great deal
of planning, and benefit from a formal, disciplined management approach. From
making sure that activities will actually meet the specified need, to devising a
workable schedule, developing systems for reporting progress, and managing re-
quests for changes – all of these issues require thoughtful consideration. Managing
projects well requires a great deal of time, skill, and finesse. There are many sides
to project management and this is what makes it so interesting and demanding.

7.1.1 Project Planning Includes

• Dividing the project into plannable stages
• When to build the project plan
• Who constructs the project plan
• Step by step guide to constructing a project plan
• Making the project plan visible, getting the project plan used
• Independent project plan reviews
• Getting resource commitments
• Time recording
• Tracking progress against the project plan
• Revising the project plan during the project

Now, After The Project Planning I’m Very Interested to Add The List Of The Components
That’s been Used in the Wireless RF Module Project. So, Here’s Gonna Be The Step By
Step Listing Of Components Of This Project Under Requirement Analysis.

Page 30

8. REQUIREMENT ANALYSIS
Requirement Analysis in electronics engineering, encompasses those tasks that
go into determining the needs or conditions to meet for a new or altered prod-
uct, taking account of the possibly conflicting requirements of the various stake-
holders, such as beneficiaries or users.
Requirement analysis is critical to the success of a development project. Require-
ments must be documented, actionable, measurable, testable, related to identi-
fied business needs or opportunities, and defined to a level of detail sufficient for
system design. Requirements can be functional and non-functional.

Any coherent and reasonable system must have requirements that define what
the system is ultimately supposed to do. A requirement is an objective that must
be met. Planners cast most requirements in functional terms, leaving design and
implementation details to the developers. In this wireless RF Module Project,
we implemented this phase of requirements gathering by collecting information
from various sources like internet & also by eternal knowledge of our trainees.
The requirement of any electronics project must be it’s components & the circuit
diagram created by using OrCAD & an etched PCB.

Conceptually, requirements analysis includes the components used while created
this project. Well, the Softwares & a PC with some other stuff(like soldering wire
etc.) also come under requirement section but they’ve been already pasted in
‘Tools To Be Used’ section, So here’s goes the Components list section, named
“Listing The Components”.!!
Page 31

8.1 Listing The Components
8.1.1 Component
Component is Defined As:
An Artifact That is One of The Individual Parts of Which a Composite Entity is Made
Up; Especially a Part That Can be Separated From or Attached To a System. So, With
The Help Of This Defination We Can Guess The Importance Of Components In Elec-
tronics Projects. Components Are The Working Modules Of Any Project That Makes
It a Worth To Work. Here, In This Sub Chapter I’m Going To Write The List Of Compo-
nents That’s Been Used To Make This Project a Worth Device.

8.1.2 Printed Circuit Board
A printed circuit board, or PCB, is used to
mechanically support and electrically con-
nect electronic components using conductive
pathways, tracks or signal traces etched from
copper sheets laminated onto a non-conduc-
tive substrate. It is also referred to as printed
wiring board (PWB) or etched wiring board.
Printed circuit boards are used in virtually
all but the simplest commercially produced
electronic devices.
A PCB populated with electronic components
is called a printed circuit assembly (PCA),
printed circuit board assembly or PCB Assem-
bly (PCBA). In informal use the term “PCB”
is used both for bare and assembled boards,
the context clarifying the meaning.
8.1.3 Capacitor
A capacitor (originally known as condenser)
is a passive two-terminal electrical compo-
nent used to store energy in an electric field.
The forms of practical capacitors vary widely,
but all contain at least two electrical conduc-
tors 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.
Page 32

8.1.4 Light-Emitting Diode
A light-emitting diode (LED) is a semiconductor light
source. LEDs are used as indicator lamps in many devices
and are increasingly used for other lighting. Introduced
as a practical electronic component in 1962, early LEDs
emitted low-intensity red light, but modern versions
are available across the visible, ultraviolet, and infrared
wavelengths, with very high brightness.

When a light-emitting diode is forward-biased (switched
on), electrons are able to recombine with electron
holes within the device, releasing energy in the form
of photons. This effect is called electroluminescent and
the colour of the light (corresponding to the energy
of the photon) is determined by the energy gap of the
semiconductor. LEDs are often small in area (less than 1
mm2), and integrated optical components may be used
to shape its radiation pattern. LEDs present many advan-
tages over incandescent light sources including lower en-
ergy consumption, longer lifetime, improved robustness,
smaller size, and faster switching. LEDs powerful enough
for room lighting are relatively expensive and require
more precise current and heat management than com-
pact fluorescent lamp sources of comparable output.

8.1.5 Liquid Crystal Display
Liquid crystal display (LCD) is a flat panel display, electronic
visual display, or video display that uses the light modulat-
ing properties of liquid crystals (LCs). LCs do not emit light
directly.

LCD displays are available to display arbitrary images (as in
a general-purpose computer display) or fixed images which
can be displayed or hidden, such as preset words, digits,
7-segment displays, etc., as in a digital clock. They use the
same basic technology, except that arbitrary images are
made up of a large number of small pixels, while other
displays have larger elements.

The LCD is more energy efficient and offers safer disposal
than a CRT. Its low electrical power consumption enables it
to be used in battery-powered electronic equipment. It is
an electronically modulated optical device made up of any
number of segments filled with liquid crystals and arrayed
in front of a light source (backlight) or reflector to produce
images in colour or monochrome. Liquid crystals were first
developed in 1888.
Page 33

8.1.6 Relay
A Relay is an electrically operated switch. Many relays
use an electromagnet to operate a switching mecha-
nism mechanically, but other operating principles are
also used. Relays are used where it is necessary to
control a circuit by a low-power signal (with complete
electrical isolation between control and controlled
circuits), or where several circuits must be controlled by
one signal.

A type of relay that can handle the high power required
to directly control an electric motor or other loads is
called a contactor. Solid-state relays control power cir-
cuits with no moving parts, instead using a semiconduc-
tor device to perform switching. Relays with calibrated
operating characteristics and sometimes multiple op-
erating coils are used to protect electrical circuits from
overload or faults; in modern electric power systems
these functions are performed by digital instruments
still called “protective relays”.

8.1.7 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. Thus, the ratio
of the voltage applied across a resistor's terminals to the
intensity of current through the circuit is called resist-
ance.
Practical resistors have a series inductance and a small
parallel capacitance; these specifications can be important
in high-frequency applications. In a low-noise amplifier
or pre-amp, the noise characteristics of a resistor may
be an issue. The unwanted inductance, excess noise, and
temperature coefficient are mainly dependent on the
technology used in manufacturing the resistor. A family
of discrete resistors is also characterized according to its
form factor, that is, the size of the device and the position
of its leads (or terminals) which is relevant in the practical
manufacturing of circuits using them.

Page 34

8.1.8 BX R433A
The BX R433A/433.92/TO39-1.5 is a true one-port,
surface-acoustic-wave (SAW) resonator in a
low-profile metal TO-39 case. It provides reliable, funda-
mental-mode, quartz frequency
Stabilization i.e. in transmitters or local oscillators operat-
ing at 433.920 MHz.
SAW - Surface Acoustic Wave Resonators are being rec-
ognized by more and more public figures because of its
good features and performances. They have been widely
used in communication, CATV, wireless remote control,
satellite receivers, radio and video transmission fields.

VTC can supply you high performance, high quality and
stability SAW resonators which frequencies cover from
50MHz to 1GHz.

8.1.9 ULN2801A
The ULN2801A is a high-voltage, high-current
Darlington transistor array. The device consists of
eight npn Darlington pairs that feature
high-voltage outputs with common-cathode
clamp diodes for switching inductive loads. The
collector-current rating of each Darlington pair is
500 mA and Output Voltage is upto 50V. The Darlington
pairs may be connected in parallel for higher current
Capability.

Applications include relay drivers, hammer drivers, lamp
drivers, display drivers (LED and gas discharge), line
drivers, and logic buffers. The ULN2801A has a 2.7-kΩ
series base resistor for each Darlington pair for operation
directly with TTL or 5-V CMOS devices.

8.1.10 Battery
An electrical battery is one or more electrochemical cells
that convert stored chemical energy into electrical en-
ergy.
There are two types of batteries: primary batteries (dis-
posable batteries), which are designed to be used once
and discarded, and secondary batteries (rechargeable
batteries), which are designed to be recharged and used
multiple times.

Page 35

8.1.11 HT12E/212 Series of Encoder
The 212 encoders are a series of CMOS LSIs for remote
control system applications. They are capable of en-
coding information which consists of N address bits
and 12N data bits. Each address/ data input can be set
to one of the two logic states. The programmed ad-
dresses/data are transmitted together with the header
bits via an RF or an infrared transmission medium upon
receipt of a trigger signal. The capability to select a TE
trigger on the HT12E or a DATA trigger on the HT12A
further enhances the application flexibility of the 212
series of encoders. The HT12A additionally provides a
38kHz carrier for infrared systems.
Features
• Operating voltage
-2.4V~5V for the HT12A
-2.4V~12V for the HT12E
• Low power and high noise immunity CMOS technology
• Low standby current: 0.1 (type.) at VDD=5V
A
• HT12A with a 38kHz carrier for infrared transmission
medium
• Minimum transmission word
-Four words for the HT12E
-One word for the HT12A
• Built-in oscillator needs only 5% resistor
• Data code has positive polarity
• Minimal external components
• HT12A/E: 18-pin DIP/20-pin SOP package

8.1.12 HT12D/212 Series of Decoders
The 212 decoders are a series of CMOS LSIs for remote
control system applications. They are paired with
Holtek’s 212 series of encoders (refer to the encoder/decod-
er cross reference table). For proper operation, a
pair of encoder/decoder with the same number of address-
es and data format should be chosen. The decoders receive
serial addresses and data from a programmed 212 series of
encoders that are transmitted by a carrier using an RF or an
IR transmission medium. They compare the serial input data
three times continuously with their local addresses. If no
error or unmatched codes are found, the input data codes
are decoded and then transferred to the output pins. The
VT pin also goes high to indicate a valid transmission. The
212 series of decoders are capable of decoding informations
that consist of N bits of address and 12N bits of data. Of this
series, the HT12D is arranged to provide 8 address bits and
4 data bits, and HT12F is used to decode 12 bits of address
information.
Page 36

Features
• Operating voltage: 2.4V~12V
• Low power and high noise immunity CMOS
Technology
• Low standby current
• Capable of decoding 12 bits of information
• Binary address setting
• Received codes are checked 3 times
• Address/Data number combination
-HT12D: 8 address bits and 4 data bits
-HT12F: 12 address bits only
• Built-in oscillator needs only 5% resistor
• Valid transmission indicator
• Easy interface with RF or an infrared transmission
Medium
• Minimal external components
• Pair with Holtek’s 212 series of encoders
• 18-pin DIP, 20-pin SOP package

8.1.13 PIC16F73
PIC is a powerful (200 nanosecond instruction execu-
tion) yet easy-to-program (only 35 single word instruc-
tions) CMOS FLASH-based 8-bit microcontroller packs
Microchip’s powerful PIC® architecture into 28-pin pack-
age and is upwards compatible with the PIC16C5X, PIC-
12CXXX and PIC16C7X devices. The PIC16F73 features 5
channels of 8-bit Analog-to-Digital (A/D) converter with
2 additional timers, 2 capture/compare/PWM func-
tions and the synchronous serial port can be configured
as either 3-wire Serial Peripheral Interface (SPI) or the
2-wire Inter-Integrated Circuit (IC) bus and a Universal
Asynchronous Receiver Transmitter (USART). All of these
features make it ideal for more advanced level A/D
applications in automotive, industrial, appliances and
consumer applications.

Features
Parameter Name Value
Program Memory Type Flash
Program Memory (KB) 7
CPU Speed (MIPS) 5
• 2 PWM 10-bit RAM Bytes
Digital Communication
192

• 25mA sink/source per I/O Peripherals 1-A/E/USART,
1-SSP(SPI/I2C)
• 2 Capture/Compare Capture/Compare/
PWM Peripherals 2 CCP
• Parallel Slave Port Timers 2 x 8-bit, 1 x 16-bit
ADC 5 ch, 8-bit
Temperature Range (C) -40 to 125
Operating Voltage Range (V) 2 to 5.5
Page 37 Pin Count 28

9. Working Of RF Module
As In The Very First Chapter Of This Report The Introduction has been Pasted.
But Now In This Chapter I’m Going To Tell The Operating Functionality Of
Wireless Radio Frequency Module Using PIC 16F73.

Before Just Directing to the working of RF Module Let us read abut the RF Current
It’s Behaviour first.

9.1 Special Properties Of RF Current
Electric currents that oscillate at radio frequencies have special properties not
shared by direct current or alternating current of lower frequencies. The en-
ergy in an RF current can radiate off a conductor into space as electromagnetic
waves (radio waves); this is the basis of radio technology. RF current does not
penetrate deeply into electrical conductors but flows along their surfaces; this
is known as the skin effect. For this reason, when the human body comes in con-
tact with high power RF currents it can cause superficial but serious burns called
RF burns. RF current can easily ionize air, creating a conductive path through it.

This property is exploited by high frequency units used in electric arc welding,
which use currents at higher frequencies than power distribution uses. Another
property is the ability to appear to flow through paths that contain insulating
material, like the dielectric insulator of a capacitor. When conducted by an ordi-
nary electric cable, RF current has a tendency to reflect from discontinuities in
the cable such as connectors and travel back down the cable toward the source,
causing a condition called standing waves, so RF current must be carried by spe-
cialized types of cable called transmission line.

9.2 Main Factors Affecting
RF Module’s Performance
As with any other radio-frequency device, the performance of an RF Module
will depend on a number of factors. For example, by increasing the transmit-
ter power, a larger communication distance will be achieved. However, this will
also result in a higher electrical power drain on the transmitter device, which
will cause shorter operating life for battery powered devices. Also, using a
higher transmit power will make the system more prone to interference with
other RF devices, and may in fact possibly cause the device to become illegal
depending on the jurisdiction.
Correspondingly, increasing the receiver sensitivity will also increase the effec-
tive communication range, but will also potentially cause malfunction due to
interference with other RF devices.

Page 38

9.3 Frequencies Chart

Fig: 9.3 Frequencies Table Of RF
Page 39

Fig 9.3.1: RF Frequency Spectrum

9.4 RF Module Interfacing with PIC
The term wireless is very much hyped! Whenever we hear the term wireless, stuffs like
Mobile telecommunication (GSM), Wi-Fi,Bluetooth, RF Communication,Wireless net-
works, Zigbee, I2C, SPI,DTMF, 802.11b, SimpliciTI etc etc etc. Well, fortunately or unfor-
tunately, all of these protocols can be interfaced with a microcontroller in one way or
the other. But what matters is, The level of complexity.

To start off, RF (Radio Frequency) Communication is the most preferred and low cost
solution. All we need is a RF Module (Transmitter-Receiver Pair). Now, that’s not all. RF
Communication works on the principle of Serial Communication. Thus, We need some-
thing which converts the conventional n-bit (4-bit, 8-bit, 16-bit, etc) data into serial
data. For this, we have two choices:
• Use a microcontroller to convert the n-bit data into serial data and vice-
versa
• Use serial encoders/decoders to do the same.
But, If We Use the Both Then It Would Be More Innovative Impressive As We’ll Be
Able To Get The Output On L.C.D As Well. For L.C.D Interfacing With Encoder/Decode
Serial Ports We Strongly Need a Microcontroller, Which In Our Project is PIC 16F73. So
Here’s The Working Below:

9.5 RF Communication Block Diagram

Fig: 9.5 Block Diagram Of RF Operation
Page 40

A general RF communication block diagram is shown above. Since most of the encod-
ers/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 trans-
mit the data through the antenna.
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.
RF Modules are used wireless transfer data. This makes them most suitable for remote
control applications, as in where we need to control some machines or robots without
getting in touch with them (may be due to various reasons like safety, etc). Now de-
pending 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: 9.5.1 Transmitter/Receiver Explained

Page 41

Features
• Range in open space(Standard Conditions) : 100 Meters
• RX Receiver Frequency : 433 MHz
• RX Typical Sensitivity : 105 Dbm
• RX Supply Current : 3.5 mA
• RX IF Frequency : 1MHz
• Low Power Consumption
• Easy For Application
• RX Operating Voltage : 5V
• TX Frequency Range : 433.92 MHz
• TX Supply Voltage : 3V ~ 6V
• TX Out Put Power : 4 ~ 12 Dbm
This has single channel for data transfer, thus serial data communication is
used.

Antenna
Now that all the connections are made, we must choose an antenna for signal trans-
mission. Usually, a 20-30 cm wire serves best. It is sufficient to give a range of 80
meters in open region. To improve the efficiency, we can also use a coiled wire (take
a wire and make it into a coil). It increases the signal strength.

Page 42

9.6 Source Code For PIC
Since, As We Know The PIC 16F73 is a Micro-Controller Which Without a Pogramming Code is As
Dumb As a Small Plastic Stuff With Having Some Sharp Pins. So, To Make This PIC Our Project’s CPU
We’ve Added The Following Programming Written In Embedded C Using MikroC As a Compiler.

Void main()
{
TRISC=0X0f; PORTB=0; // PORTC is Considered As Input PORTB As Output.

LCD_Init(PORTB); // Initilize The LCD Connected On PORTB.
LCD_Cmd(LCD_CLEAR); // Clear display.
LCD_Cmd(LCD_CURSOR_OFF); // Turn cursor off.
LCD_Out(1,1,Device 1 is );
LCD_Out(2,1,Device 2 is );
LCD_Out(2,9,OFF);
LCD_Out(1,9,OFF);

while(1) // An Infinite Loop.
{

if(PORTC.F0==0)
{
LCD_Out(2,9,OFF);
LCD_Out(1,9,OFF);
PORTC.F6=0; // The Decision Oriented Pin Of PORTC.
PORTC.F7=0; // The Decision Oriented Pin Of PORTC.
}

if(PORTC.F1==0)
{
LCD_Out(2,9,OFF);
LCD_Out(1,9,ON);
PORTC.F6=1;
PORTC.F7=0;
}

if(PORTC.F2==0)
{
LCD_Out(2,9,ON);
LCD_Out(1,9,OFF);
PORTC.F6=0;
PORTC.F7=1;
}

if(PORTC.F3==0)
{
LCD_Out(2,9,ON);
LCD_Out(1,9,ON);
PORTC.F6=1;
PORTC.F7=1;
} }}
Page 43

9.7 Serial Encoder/Decoder
The most popular serial encoder/decoder used is the HT12D-HT12E pair. 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 address bits 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
The HT12D Decoder ICs are series of CMOS LSIs for remote control system applica-
tions. 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.
The Decoder receive the serial address and data from its corresponding decoder,
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
Applications • Minimal External Components

• Burglar Alarm, Smoke Alarm, Fire Alarm, Car Alarm, Security System
• Garage Door and Car Door Controllers
• Cordless telephone
• Other Remote Control System Compatibility
• Compatible with RF Modules 433 MHz Link RF Modules (Tx + Rx Pair)
Page 44 433Mhz

Troubleshooting
It’s obvious that we won’t get the result in the first go itself! It’s completely
normal, even in any case! . In that case, just try out the simple wired communica
tion. Connect the DOUT of the encoder directly to the DIN of the decoder using
a wire. Then check and recheck your connections, check whether the address is
the same, whether you have missed any Vcc or GND connection, etc. If still then a
successful link is not established, change the encoder/decoder ICs. Once the link
is established, connect the RF module and do the same. Try adjusting the antenna
position, touch the antenna (touching the antenna will make yourself an
antenna!), etc.

9.8 How Do RF Transmitters And Receivers
Work?
An RF transmitter generates radio frequency waves in its circuits, and to this
'carrier signal', it adds the information part by modulating the carrier signal. This
composite signal (carrier plus information) is then fed to an antenna (aerial).

The aerial induces a corresponding signal into the atmosphere, by altering the
Electric and Magnetic fields at (obviously) the same frequency. The impedance of
'free space' is few tens of Ohms to a few hundreds of Ohms.
[Impedance may be considered analogous to resistance, but with reactive prop-
erties as well.] The power emitted by the transmitter can vary from a megawatt
or so (for VLF signals) to a few watts for handheld devices.
An Rf receiver receives the signal from the atmosphere, from its own aerial.
The receiver aerial is often quite simple, and the signal level is typically of a few
microvolts. This it tunes in (gets rid of unwanted signals and amplifies only the
wanted ones).
The receiver circuits then strip the information part of the signal from the carrier
part, and amplify this to a useful level for audio or video.
The actual signal into the loudspeaker will be a few tens of volts. In spite of the
inefficiency of loudspeakers, (often only a few %) the signal eventually appears at
a level that may be heard. A background radio will be a few milliwatts of power.
Even a very loud sound is only a few watts of radiated (sound) energy!!

Page 45 Fig: 9.8 RF Module

9.9 Circuit Implementation
9.9.1 Transmitter Section

Make the following circuit on an etched PCB. Here, we have used four switch-
es S1, S2, S3 and S4 to give 4-bit parallel data (D0-D3). Since the switches
are in active low state (i.e. low signal is sent when the switch is pressed), we
need to add external pull-up resistors as shown, so as to provide a high signal
by default. A resistance as high as 1M ohm is required in between OSC1 and
OSC2 pins. The Transmitter Enable (TE, pin 14) pin is an active low pin. Thus,
it is permanently grounded, so as to enable the transistor always. The output
serial data DOUT is fed to the RF Transmitter Module directly.
The most important thing lies in the address pins (A0-A7, pin1-8). Suppose we
have two wireless devices (A and B) in our house, both have different remote
controls (AA and BB) and both implement the same type of RF module (say
433 MHz). AA is the remote control of A and BB is of B. Now, we obviously
wouldn’t want AA to control B (which is the most probable case since both the
devices use same kind of RF module, having same frequency!). This is where
address pins come into play. There are 8 address pins, thus giving us an oppor-
tunity to have 8! (8 factorial) different and independent ways to connect to a
device, so that there is no interference. The address pins MUST have the same
address in both transmitter and receiver, or else the data won’t be transferred.
Refer to the receiver circuit for more details.

Fig: 9.9.1 Operation Of Serial Encoder
Page 46

9.9.2 Receiver Section
The circuit of the receiver is also quite simple. Capacitor C1 is used be-
tween Vcc and GND for noise filtering. Apart from that, all the address
pins (A0-A7, pin 1-8) are grounded, just as in transmitter. This is to en-
sure that the transmitted data is being received. Both the transmitter
and the receiver MUST have the same address pins configuration. Pin
17 (VT) is enabled whenever the receiver receives any data. The serial
data received by the RF Receiver module is directly fed to pin 14 (DIN),
which is then converted into 4-bit parallel data (D0-D3). A 33k ohm
resistor is connected in between OSC1 and OSC2.

Fig: 9.9.2 Operation Of Serial Decoder

Page 47

9.10 Operational Function Of Transmitter Receiver
Through Flowchart

Fig: 9.10 Flowchart Of RF Module

Page 48

10.WHAT iS HEX FiLE FoRmAT AnD How’S IT WoRK?
When We Create a Program Build It (Or Run It), The Compiler Creates
a File With Having An Extension “.hex”. This .hex Extension Plays Very
Important Role While Burning The Program Also It Provides An Ap-
propriate Help For User To Interface The Micro-Controller With Serial
Ports Let It To Work.

The Intel hex (ihex) generally known as hex file, is a format used to store machine
language code in hexadecimal form. It is widely used format to store programs
to be transferred to microcontrollers, ROM and EEPROM. The compilers convert
the programs written in assembly, C etc into corresponding hex files, which are
dumped into the controllers using burners/programmers.

The microcontroller understands machine language consisting of zeroes and ones.
It’s difficult rather practically impossible for humans to write codes in zeros and
ones. Hence we use some high level languages like C, C++, Java, etc. And later a
compiler is used to convert these codes into machine language which are stored in
a hex file format. A hex file is a text file with the extension .hex.

10.1 Structure Of .hex File
1. Every line in a hex file always starts from colon (:)
2. The first two digits CC (Character Count) represent the total number of data
byte in that line. Here in this example, 10 (hexadecimal) are the first two digits
which mean that there is 16 byte (in decimal) of data in the line.
3. The next four digits represent the starting address of the memory where the
data stored in the line needs to be dumped. 4. After address the next two
digits represent whether this is the last line of code or not. TT=0, means the
code is not complete and there are more lines after this line and TT=1 means
this is the last line of the code.
5. XXXX…..XX are the data bytes which have to be dumped into the memory. The
number of data bytes in a particular line is equal to the number indicated by
character count digits (CC).
6. SS is the checksum byte of that line.
The hex file is a text file so one can easily change contents of a hex file.
The corrupted line can be identified using the check sum) (SS) byte.
Page 49

11. Applications Of Wireless RF Module
The very first thing that concern to any engineering student before choosing the
project is it’s Applications. That means How much innovative the project is ? And
How We can make it more innovative also make it up-to-date so that it can
extend to the bigger Applications of this age of Smart Vast life. And, Also It’s Ap-
plications must be cost effective so that everyone can use it without any economi-
cal hesitation.
The Application Of Any Project is Considered as The Future Insight Of That Project.

The Very Best Application of Radio Frequency is RFID

11.1
Radio-frequency identification (RFID) is the use of a wireless non-contact
system that uses radio-frequency electromagnetic fields to transfer data from a
tag attached to an object, for the purposes of automatic identification and track-
ing. Some tags require no battery and are powered by the electromagnetic fields
used to read them. Others use a local power source and emit radio waves (elec-
tromagnetic radiation at radio frequencies). The tag contains electronically stored
information which can be read from up to several meters (yards) away. Unlike a
bar code, the tag does not need to be within line of sight of the reader and may be
embedded in the tracked object.

RFID tags are used in many industries. An RFID tag attached to an automobile dur-
ing production can be used to track its progress through the assembly line. Phar-
maceuticals can be tracked through warehouses. Livestock and pets may have tags
injected, allowing positive identification of the animal. RFID identity cards can give
employees access to locked areas of a building, and RF transponders mounted in
automobiles can be used to bill motorists for access to toll roads or parking. Since
RFID tags can be attached to clothing, possessions, or even implanted within peo-
ple, the possibility of reading personally-linked information without consent has
raised privacy concerns.

11.1.1 Operation Of RFID
A radio-frequency identification system uses tags, or labels attached to the objects
to be identified. Two-way radio transmitter-receivers called interrogators or readers
send a signal to the tag and read its response. The readers generally transmit their
observations to a computer system running RFID software or RFID middle ware.
The tag's information is stored electronically in a non-volatile memory. The RFID tag
includes a small RF transmitter and receiver. An RFID reader transmits an encoded
radio signal to interrogate the tag.
The tag receives the message and responds with its identification information. This
may be only a unique tag serial number, or may be product-related information such
as a stock number, lot or batch number, production date, or other specific informa-
tion. Tags may either be read-only, having a factory-assigned serial number that is
used as a key into a database, or may be read/write, where object-specific data can
be written into the tag by the system user. Field programmable tags may be write-
once, read-multiple; “blank” tags may be written with an electronic product code by
the user.
Page 50

RFID tags contain at least two parts: an integrated circuit for storing and process-
ing information, modulating and demodulating a radio-frequency (RF) signal,
collecting DC power from the incident reader signal, and other specialized func-
tions; and an antenna for receiving and transmitting the signal.

Fixed readers are set up to create a specific interrogation zone which can be
tightly controlled. This allows a highly defined reading area for when tags go in
and out of the interrogation zone. Mobile readers may be hand-held or mounted
on carts or vehicles.

Fig: 11.1.1 RFID

11.1.2 Applications Of RFID
The RFID tag can be affixed to an object and used to track and manage inventory,
assets, people, etc. For example, it can be affixed to cars, computer equipment,
books, mobile phones, etc. In social media, RFID is being used to tie the physical
world with the virtual world. RFID in Social Media first came to light in 2010 with
Facebook's annual conference.
RFID offers advantages over manual systems or use of bar codes. The tag can be
read if passed near a reader, even if it is covered by the object or not visible. The
tag can be read inside a case, carton, box or other container, and unlike bar-
codes, RFID tags can be read hundreds at a time. Bar codes can only be read one
at a time. RFID can be used in a variety of applications, such as:

• Access management
• Tracking of goods
• Tracking of persons and animals
• Toll collection and contactless payment
• Machine readable travel documents
• Smartdust (for massively distributed sensor networks)
• Tracking sports memorabilia to verify authenticity
• Airport baggage tracking logistics
Page 51

11.2 Wireless Mouse Technology
The mouse is an extremely popular device. While the majority of mice are
connected directly to the computers peripheral input via a cord and the com-
puter’s main power powers it, wireless mice are becoming extremely popular
as they give computer users cordless accessibility to their mice and their com-
puter.

Wireless mice usually work via radio frequencies commonly referred to as RF.
RF wireless mice require two components to work properly – a radio transmit-
ter and a radio receiver.

11.2.1 RF Transmitter
A radio frequency (RF) transmitter is usually integrated inside the mouse.
The mouse records its movements and buttons that are clicked and then sends
this information via radio signals to the receiver.

11.2.2 RF Receiver
The radio frequency (RF) receiver usually connects to the computer’s periph-
eral mouse input. It receives these RF signals, decodes them, and then sends
these signals directly to the computer as normal. RF receivers usually come
in a few styles. The majority come as built in components that connect to the
mouse input, others come as a separate card that is installed in one of the
many expansion slots of computers, and the third type of receiver is a sepa-
rate unit that is connected to a cable going directly to the computer’s periph-
eral input. Since the technology has been mastered, most wireless mice have
integrated receivers that plug into a computer’s peripheral input and are very
small in size.

11.2.3 RF Frequencies
Wireless mice mainly use Radio frequencies to transmit data from the mouse
to the computer. The most common type of RF is the 802.11b or 802.11g.
These frequencies operate at 2.4 gigahertz and at these frequencies a mouse
can transfer data at very quick speeds, either 11 Mbps or 56 Mbps. 2.4 giga-
hertz frequencies. These frequencies are very stable and usually have little
or no interference in a work or home environment. They also have a decent
range of about 100 to 150 feet which is more than enough for mouse
operation.

Page 52

11.2.4 Advantages of Wireless Mice
RF wireless mice are a great technology because of their overall reliabil-
ity and stability. Other forms of communication such as Infrared technol-
ogy need to be in “line of sight” in order to work properly, which makes
using them with a mouse impractical.
Some of the reasons that RF technology is great for wireless mice
includes the fact that the RF transmitter housed in the mouse requires
low power. Usually, RF wireless mice are powered by small, light weight
batteries that are either disposable or usually rechargeable with an
included recharging dock.

Fig: 11.2.4 Wireless RF Based Mouse

11.3 Industrial Automation
In Industrial automation there is an ever-increasing need to monitor and
analyse the status or wear and tear of machines and sensors. Using the low
power wireless connectivity of the RF Module is a low cost high
Reliability method of getting access to this data. A series of mRF prototypes
consisting of a contact mechanism and actuator with return spring were
fabricated assembled, inspected, and characterized for electromechanical
performance. Characterization results led to specific conclusions regarding
capabilities of the mRF product, and the integrated manufacturing tech-
nique.
The performance objectives of low RF loss, high electrical isolation, and de-
vice compactness drive the fabrication requirements for modern RF relays.
and contact resistance for consistent electrical response.
Like: Stationary Transmitter Systems etc.
Page 53

11.4 Custom Wireless Remote Controls
The applications for simple RF wireless switching are limitless. Nearly any device
that can be electrically turned on or off can be controlled remotely using Re-
mote Control Technology's wireless switching technology. From tactical airfield
lighting to automating pump operations, Remote Control Technology's goal is to
provide a Simple Wireless Solution that is easy to install and operate. The
following are a few examples companies with custom built systems:

11.4.1 wireless x-ray systems
The Need: L3 needed to integrate a wireless perimeter detec-
tion system into their CX-2500M mobile X-ray screening system
using Southwest Microwaves M.I.L. PAC 385 system. The unit
needed to operate at a EU compliant radio frequency and have
multiple safety backups.

The Solution: Remote Control Technology modified several
wireless switch systems to have an increased rate of transmis-
sion. This way, a barrier penetration or a twelve second failure
to transmit (potential vandalism or system error) would be de-
tected. In addition, a custom handheld transmitter and keypad
were designed to allow operators a means to enable and dis-
able the system.

11.4.2 Long-Range Wireless
Switch System (Hand-Held)

The Long Rang Wireless Switch System Hand Held (LRWSSHH) is
designed for long range and simple wireless switching. Applica-
tions where faulty wire replacement or new installation is not
possible or practical, the LRWSSHH is the simple solution for:

• Pump Control • Center Pivots • PLC Activation
• Valve Actuation • Light Control • Engine Control
• Conveyor Control • Alarm Systems • Wireless Automation

Page 54

11.5 Machine To Machine (M2M) RF
Wireless Networking
Machine-to-machine (M2M) refers to the technologies that allow both wire-
less and wired systems to communicate with other devices of the same abil-
ity. M2M uses a device (such as a sensor or meter) to capture an event (such
as temperature, inventory level, etc.), which is relayed through a network
(wireless, wired or hybrid) to an application (software program), that trans-
lates the captured event into meaningful information (for example, items
need to be restocked). Such communication was originally accomplished by
having a remote network of machines relay information back to a central
hub for analysis, which would then be rerouted into a system like a personal
computer.

However, modern M2M communication has expanded beyond a one-to-one
connection and changed into a system of networks that transmits data to
personal appliances. The expansion of wireless networks across the world
has made it far easier for M2M communication to take place and has less-
ened the amount of power and time necessary for information to be com-
municated between machines. These networks also allow an array of new
business opportunities and connections between consumers and producers
in terms of the products being sold.
Machine to Machine wireless communication has many applications, from
cost recovery solutions to equipment monitoring and environmental
observation.

Fig: 11.5

Page 55

11.6 Robot Control Using RF Module
A Robot is a mechanism that can move automatically. A system designed to
record and report on discrete activities within a process is called as Track-
ing System. In the same procedure user can develop a methodology of robot
direction system for robotics to control and achieve accurate direction for a
class of non-linear systems in the presence of disturbances and parameter
variations by using wireless communication technique.

The simple system created using RF module track the robot by using wireless
communication i.e. from Control section (acts as transmitter) An ejecting the
control signals, then the robot receives (acts as receiver) the signals, accord-
ing to the signals it will change the direction in different paths like forward,
backward, left, right.
Simple robot is easy to set up, And support the required hardware as desired
and also serves as the needs in future.

Specifications:

1. Micro controller
2. Dc gare motors
3. Relays
4. Uln2003
5. Rf modules
6. Power supply

Fig: 11.6 Flowchart Of RF Based Control Robot
Page 56

12. ACTUAL PCB PHoToGRApHS

Receiver End Of Project (RF-RX)

Transmitter End Of Project (RF-TX)
Page 57

Sending The Signal From Transmitter

Receiver Installed On PIC Based PCB With Transformer Relay Connected

Additional Output Showing On Installed LCD
Page 58

13. Future OF PROJECT
As, We Know the Second thing after the Applications of any project which con-
cerns the most to any electronics student is the future of that project by any
means, off course. So, Here in following chapter I’m going to Add some of the
possible Futuristic Insights Of Wireless RF Module. And, Well Try Not To Be ‘Ray
Kurzweil’ ‘Stephen Hawking’ , This Futuristic Insight May not be Very Impres-
sive Innovative but this would definately be the best possible Insights Abut
the project.
13.1
Identifying Objects Using RF Transmitters And Receivers and Retrieving
Data Using GSM
Abstract—
To provide a system for monitoring and locating
objects using Radio Frequency (RF) transmitters and receivers,
and querying about the objects using mobile phones. An object
represents a real world entity. This system is based on RF
transmitters that are tagged to the objects of everyday use and
have the capability of transmitting signals and a receiver that
detects the transmission of the tagged object and stores its
corresponding location in the database which is created
specifically for information maintenance of the tagged objects.
Mobile phones are used to query the location of the tagged
object by sending a message to the Subscriber Identity Module
(SIM) connected to a Global System for Mobile
Communications (GSM) modem. This GSM modem fetches the
location and other relevant information from the database and
Encapsulates this information into a message which is sent back
to the mobile phone that has requested the information.

13.2 Radio Transmitter Design
Abstract—
Radio transmitter design is a complex topic which can be broken
down into a series of smaller topics. A radio communication system
requires two tuned circuits each at the transmitter and receiver, all
four tuned to the same frequency. The transmitter is an electronic
device which, usually with the aid of an antenna, propagates an
electromagnetic signal such as radio, television, or other telecom-
munications.

• The transmitting system consists of two tuned circuits
such that the one containing the spark-gap is a persistent
Oscillator; the other, containing the aerial structure, is a
free radiator maintained in oscillation by being coupled to
the first (Nikola Tesla and Guglielmo Marconi).
• The oscillating system, including the aerial structure with
its’ associated inductance-coils and condensers, is de
Signed to be both a sufficiently persistent oscillator and a
Page 59 Sufficiently active radiator (Oliver Lodge).

13.3 Two Channels RF Remote Control
Abstract—
How many times have we need some remote control to handle
some electric device ? Many times,off course. There are lot of
remote controls like infrared, RF, SMS and more. The basic small-
range remote controls are 2, Infrared and RF (Radio Frequency).
One of the weaks of Infrared is that the signal can not pass the
walls. So, if we want to control our garage door, the only way is to
use some RF remote control. The circuit (transmitter and receiver)
uses few components and ordinary. It's easy to be built because
we don't have to tune-up any coil or variable capacitor. The RF
modules are fix to work in 418MHz area.

Any RF Based Remote Control Having Following Categories Can Be
Designed For It’s Future Uses With Some Advance Knowledge:

a.) The verification of the received data because many other
devices are working in this frequency (418MHz)
b.) And the power-saving of the transmitter. A transmitter must
have long battery life. It's not the best choice for a user to
change the battery every 3 days.
c.) The receiver`s power supply should be of long life, because
receiver must be working all the time.

The Following Components could be used:
The power supply of the RF receiver is constituted by 2 voltage
regulator, LM7812 and LM7805. The first one (12V) is only for pow-
ering the 2 relays and the 2nd (5V) for powering the AVR microcon-
troller and the RF receiver module. The LED, is a voltage indicator
and the 4 capacitors should be for flattening the voltage.

13.4 Weather Monitoring System
Abstract—
Well, this might be considered as a complex project to work with
RF, But RF Module system could be used best with Weather Moni-
toring System. In Weather Monitoring System we’re supposed to
put a transmitter with having some kind of sensors ( like Temp.
Sensors, Heat sensors, Rain sensors etc. ) Installed on it placed at
any open place or on the roof of house. That transmiter would
send current updates of weather to the receiver which is placed at
the ground floor of the house using RF Communication. And, this
RF system becomes the live updation system for a comman house
hold families. Also, we can add some kind of Warning buzzer or LCD
display messages for weather notifications. This definately could be
considered as one of the most innovative project with RF Module.

Page 60

14. AppEnDiX
Abstraction allows us to layer semantics of complex system, breaking
them into more manageable pieces.
Radio Frequency : Radio Frequency (RF) is a rate of oscillation in the range of about 3
kHz to 300 GHz
Device : An instrumentality invented for a particular purpose
Wireless : Wireless is a term used to describe telecommunications in which
Electromagnetic waves carry the signal over part or all of the communication
path.
Module : A self-contained component (unit or item) that is used in combination with
other components
LED : Light Emitting Diode
LCD : Liquid Crystal Display
USB : Universal Serial Bus; a way of attaching peripheral devices to a computer
OrCAD : Oregon + CAD, OrCAD is a proprietary software tool suite used primarily for
electronics design automation
PCB : Printed circuit board (PCB) provides both the physical structure for mounting and
holding the components as well as the electrical interconnection between the
components.
Capture CIS : Component information system (CIS), A Part Of OrCAD Suite Used For Ckt
Designing.
Mikro C : MikroC is a powerful, feature rich development tool (Compiler) for
PICmicros.
Bootloader : The bootloader receives a user program from the PC and writes it in
the flash memory, then launches this program in execution.
Net-list : Net-list file is a document file which contains information about the logical
Interconnections between signals and pins.
Layout Plus : Layout plus is one part for the PCB design in which we place as well
as route the components an set unit of measurement, grids, and
spacing in OrCad.
PIC Burner : PIC Burner is very versatile software. We can use different kinds of
hardware with it, because the pins used on parallel port can be set using
a simple ini-file.
PIC : Peripheral Interface Controller, A Micro-Controller
USART : Universal Synchronous Asynchronous Reciever Transmitter
RFID : Radio Frequency Identification
Communication : The activity of communicating; the activity of conveying information
Automation : The act of implementing the control of equipment with advanced
technology; usually involving electronic hardware
Transmitter : Any Device Set used to broadcast radio or tv signals

Page 61 Receiver : Any Device Set that receives radio or tv signals

15. BIBL IOGRAPHY

Books:
PIC Microcontroler Notes - NetMax Technologies.

Data Sheet- PIC16F73 - Microchip Co. LTD.
Data Sheet - HT12E/212 Encoder
12
Holtek Co. LTD.
- HT12D/2 Decoder
Data Sheet - ULN 280 - Texas Instruments CO. LTD.

Web Links:
http://www.wikipedia.org/

http://www.alldatasheet.com/

http://www.microchip.com/

http://www.remotecontroltech.com/

http://www.rentron.com/

http://howstuffworks.com/

http://Mikroelektronika.com/

Page 62

Personal Notes
Well, Guys Please Don’t consider this page as an another boring chap-
ter of this report of RF Project. I’m Abhi Sharma, The Person Who Cre-
ated That Project it’s Report. In This Page I’d like to Add Some of My
External Stuffs that would definitely be helpful for future purpose
if you bother to work on the same project. As long as I believe, This
Project Report Covers almost everything that It requires to hold for
a complete an unabridged report should do. It Contains data from
data sheets, Web links Journals so it obviously is an accurate stuff to
heed on.

Actually, the Main purpose of this ‘Personal Note’ Page is that In pdf I
Can’t Add All the Related stuff to the project. i mean the Video, Images
Presentation etc. You know, it would very unhandy It’d increase
the size of Document at a great extent It definitely would make the
document very unstable. So, To deal with this problem I’ve find a way
to provide you a link to an organized stack That’d lead you to the re-
lated stuff of the project. So, Please Do Click on the Following icon of
delicious.com get the stack into your browser.
Abhi
:)

Page 63

PIC Microcontroller Features (Explained) systems
Microcontroller 7

* Extra Stuff
1.3.1 Supply voltage
Most microcontrollers operate with the standard logic voltage of ϩ5 V Some microcontrollers
.
can operate at as low as ϩ2.7 V and some will tolerate ϩ6 V without any problems. You should
check the manufacturers’ data sheets about the allowed limits of the power supply voltage.

A voltage regulator circuit is usually used to obtain the required power supply voltage when the
device is to be operated from a mains adaptor or batteries. For example, a 5 V regulator is required
if the microcontroller is to be operated from a 5 V supply using a 9 V battery.

1.3.2 The clock
All microcontrollers require a clock (or an oscillator) to operate. The clock is usually provided by
connecting external timing devices to the microcontroller. Most microcontrollers will generate clock
signals when a crystal and two small capacitors are connected. Some will operate with resonators or
external resistor–capacitor pair. Some microcontrollers have built-in timing circuits and they do not
require any external timing components. If your application is not time-sensitive you should use
external or internal (if available) resistor–capacitor timing components for simplicity and low cost.

An instruction is executed by fetching it from the memory and then decoding it. This usually takes
several clock cycles and is known as the instruction cycle. In PIC microcontrollers an instruction
cycle takes four-clock periods. Thus, the microcontroller is actually operated at a clock rate which
is a quarter of the actual oscillator frequency.

1.3.3 Timers
Timers are important parts of any microcontroller. A timer is basically a counter which is driven
either from an external clock pulse or from the internal oscillator of the microcontroller. A timer
can be 8-bits or 16-bits wide. Data can be loaded into a timer under program control and the timer
can be stopped or started by program control. Most timers can be configured to generate an inter-
rupt when they reach a certain count (usually when they overflow). The interrupt can be used by
the user program to carry out accurate-timing-related operations inside the microcontroller.

Some microcontrollers offer capture and compare facilities where a timer value can be read when
an external event occurs, or the timer value can be compared to a preset value and an interrupt can
be generated when this value is reached.

It is typical to have at least one timer in every microcontroller. Some microcontrollers may have
two, three, or even more timers where some of the timers can be cascaded for longer counts.

1.3.4 Watchdog
Most microcontrollers have at least one watchdog facility. The watchdog is basically a timer which
is refreshed by the user program and a reset occurs if the program fails to refresh the watchdog. The

8 PIC BASIC projects

watchdog timer is used to detect a system problem, such as the program being in an endless loop.
A watchdog is a safety feature that prevents runaway software and stops the microcontroller from
executing meaningless and unwanted code. Watchdog facilities are commonly used in real-time
systems where it is required to regularly check the successful termination of one or more activities.

1.3.5 Reset input
A reset input is used to reset a microcontroller. Resetting puts the microcontroller into a known
state such that the program execution starts from address 0 of the program memory. An external
reset action is usually achieved by connecting a push-button switch to the reset input such that the
microcontroller can be reset when the switch is pressed.

1.3.6 Interrupts
Interrupts are very important concepts in microcontrollers. An interrupt causes the microcon-
troller to respond to external and internal (e.g. a timer) events very quickly. When an interrupt
occurs the microcontroller leaves its normal flow of program execution and jumps to a special
part of the program, known as the Interrupt Service Routine (ISR). The program code inside the
ISR is executed and upon return from the ISR the program resumes its normal flow of execution.

The ISR starts from a fixed address of the program memory. This address is also known as the
interrupt vector address. For example, in a PIC16F84 microcontroller the ISR starting address is
4 in the program memory. Some microcontrollers with multi-interrupt features have just one
interrupt vector address, while some others have unique interrupt vector addresses, one for each
interrupt source. Interrupts can be nested such that a new interrupt can suspend the execution of
another interrupt. Another important feature of a microcontroller with multi-interrupt capability
is that different interrupt sources can be given different levels of priority.

1.3.7 Brown-out detector
Brown-out detectors are also common in many microcontrollers and they reset a microcontroller
if the supply voltage falls below a nominal value. Brown-out detectors are safety features and they
can be employed to prevent unpredictable operation at low voltages, especially to protect the con-
tents of EEPROM-type memories.

1.3.8 Analogue-to-digital converter
An analogue-to-digital converter (A/D) is used to convert an analogue signal such as voltage to a
digital form so that it can be read by a microcontroller. Some microcontrollers have built-in A/D
converters. It is also possible to connect an external A/D converter to any type of microcontroller.
A/D converters are usually 8-bits, having 256 quantisation levels. Some microcontrollers have
10-bit A/D converters with 1024 quantisation levels. Most PIC microcontrollers with A/D features
have multiplexed A/D converters where more than one analogue input channel is provided.

Microcontroller systems 9

The A/D conversion process must be started by the user program and it may take several hundreds
of microseconds for a conversion to complete. A/D converters usually generate interrupts when a
conversion is complete so that the user program can read the converted data quickly.

A/D converters are very useful in control and monitoring applications since most sensors (e.g.
temperature sensor, pressure sensor, force sensor, etc.) produce analogue output voltages.

1.3.9 Serial I/O
Serial communication (also called RS232 communication) enables a microcontroller to be con-
nected to another microcontroller or to a PC using a serial cable. Some microcontrollers have
built-in hardware called USART (Universal Synchronous–Asynchronous Receiver–Transmitter)
to implement a serial communication interface. The baud rate and the data format can usually be
selected by the user program. If any serial I/O hardware is not provided, it is easy to develop soft-
ware to implement serial data communication using any I/O pin of a microcontroller. We shall see
in Chapter 4 how to use the PicBasic and PicBasic Pro statements to send and receive serial data
from any pin of a PIC microcontroller.

Some microcontrollers incorporate SPI (Serial Peripheral Interface) or I2C (Integrated Inter
Connect) hardware bus interfaces. These enable a microcontroller to interface to other compatible
devices easily.

1.3.10 EEPROM data memory
EEPROM type data memory is also very common in many microcontrollers. The advantage of an
EEPROM memory is that the programmer can store non-volatile data in such a memory, and can
also change this data whenever required. For example, in a temperature monitoring application
the maximum and the minimum temperature readings can be stored in an EEPROM memory.
Then, if the power supply is removed for whatever reason, the values of the latest readings will
still be available in the EEPROM memory.

PicBasic and PicBasic Pro languages provide special instructions for reading and writing to the
EEPROM memory of a microcontroller which has such memory built-in.

Some microcontrollers have no built-in EEPROM memory, some provide only 16 bytes of
EEPROM memory, while some others may have as much as 256 bytes of EEPROM memories.

1.3.11 LCD drivers
LCD drivers enable a microcontroller to be connected to an external LCD display directly.
These drivers are not common since most of the functions provided by them can be implemented
in software.

10 PIC BASIC projects

1.3.12 Analogue comparator
Analogue comparators are used where it is required to compare two analogue voltages. Although
these circuits are implemented in most high-end PIC microcontrollers they are not common in
other microcontrollers.

1.3.13 Real-time clock
Real-time clock enables a microcontroller to have absolute date and time information continu-
ously. Built-in real-time clocks are not common in most microcontrollers since they can easily be
implemented by either using a dedicated real-time clock chip, or by writing a program.

1.3.14 Sleep mode
Some microcontrollers (e.g. PIC) offer built-in sleep modes where executing this instruction puts
the microcontroller into a mode where the internal oscillator is stopped and the power consump-
tion is reduced to an extremely low level. The main reason of using the sleep mode is to conserve
the battery power when the microcontroller is not doing anything useful. The microcontroller usu-
ally wakes up from the sleep mode by external reset or by a watchdog time-out.

1.3.15 Power-on reset
Some microcontrollers (e.g. PIC) have built-in power-on reset circuits which keep the microcon-
troller in reset state until all the internal circuitry has been initialised. This feature is very useful
as it starts the microcontroller from a known state on power-up. An external reset can also be pro-
vided where the microcontroller can be reset when an external button is pressed.

1.3.16 Low power operation
Low power operation is especially important in portable applications where the microcontroller-
based equipment is operated from batteries. Some microcontrollers (e.g. PIC) can operate with
less than 2 mA with 5 V supply, and around 15 ␮A at 3 V supply. Some other microcontrollers,
especially microprocessor-based systems where there could be several chips may consume sev-
eral hundred milliamperes or even more.

1.3.17 Current sink/source capability
This is important if the microcontroller is to be connected to an external device which may draw
large current for its operation. PIC microcontrollers can source and sink 25 mA of current from
each output port pin. This current is usually sufficient to drive LEDs, small lamps, buzzers, small
relays, etc. The current capability can be increased by connecting external transistor switching
circuits or relays to the output port pins.
These are some features Of PIC Controllers that I found while creating this doc. Unfortunately
I forgot to add it in my Report so I'm Putting it at the last. I Strongly believe it is very well
explained understandable. Thanxx, - Abhi Sharma :)

Wireless Radio Frequency Module Using PIC Microcontroller.

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