PROJECT WORK

ON

FM BASED LONG RANGE REMOTE CONTROL

For the partial fulfillment of the

requirements for the award of the Diploma

in Electronics and Communication

Engineering of the Department of Technical

Education

Submitted By

C.M. RAJA R.K. VIGNESH

J. VICTOR JEGAN E. RAJ KUMAR

S. ARICHANDRAN T. JEGATHESH

Guided by

Mr. G. V. PREM KUMAR., B.E

DEPARTMENT OF ELECTRONICS &

COMMUNICATION ENGINEERING

GOVERNMENT POLYTECHNIC COLLEGE

NAGERCOIL – 629 004.

2005-2006

FM BASED LONG RANGE REMOTE CONTROL

PROJECT REPORT

CERTIFICATE

Certified that this is the bonafide recode of project work on

“FM BASED LONG RANGE REMOTE CONTROL” done by

Mr.

Reg. No: of Final year Electronics &

Communication Engineering during the year 2005-2006

Project Guide Head of the Department

Submitted for the Board Examinations, April 2006

Internal Examiner External Examiner

ACKNOWLEDGEMENT

We wish to thank the GOD “Who is invisible without him nothing is

possible.” We here by acknowledge our sincere thanks to our Principal,

TMT.C.J.HONIBALD M.E., MISTE, for her constant encouragement and

blessing.

We express our sincere and hearty thanks to our Head of Electronics

& Communication Engineering department & our guide

Mr. G. V. PREM KUMAR., B.E. for his source inspiration and technical

guidance throughout this project.

We also express our sincere thanks to our teaching & non teaching

staffs & friends for their co-operation to complete this project.

CONTENTS

1. SYNOPSIS

2. INTRODUCTION

3. BLOCK DIAGRAM

4. CIRCUIT DESCRIPTION

5. FLOW CHART

6. PROGRAM

7. PCB PREPARATION

8. ESTIMATION

9. CONCLUSION

10. BIBLIOGRAPHY

1. SYNOPSIS

The Project Long Range Remote Control can be used to remotely

control a number of Electrical or Electronic Gadgets connected to it. Unlike

Infra Red remote control, this Project employs FM transmission and

Reception, and hence it can be used for comparatively longer range.

Any gadget can be switched on/off by keying the number allocated to

it. The Receiver is made up of the famous 8 bit Microcontroller from Atmel.

The Microcontroller is used as the Master in the receiver end which is used

to control all the devices. It decodes the Signal from the transmitter and

control the relays according to the signal. For transmission we are using

frequency modulation at the frequency of 433.92Mhz.

2. INTRODUCTION

A microcontroller unit (MCU) uses the microprocessor as its

central processing unit (CPU) and incorporates memory, timing reference,

I/O peripherals, etc on the same chip. Limited computational capabilities and

enhanced I/O are special features.

In our Project the Microcontroller is used to control all the External

devices. The Transmitter transmits the signal using the FM transmitter.

In the receiver end the FM receiver is used to receive the FM signal

and its output contains the digital signal. The digital signals are decoded by a

decoder and the outputs are coupled to the microcontroller. It controls the

External devices through the Relays.

In our Project we are using the 8-bit Microcontroller AT89C2051

from Atmel semiconductors

3. BLOCK DIAGRAM

BLOCK DIAGRAM OF THE TRANSMITTER SECTION

BLOCK DIAGRAM OF THE RECEIVER SECTION

Block Diagram Explanation

3.1. WHAT IS A MICROCONTROLLER?

A microcontroller (often abbreviated MCU) is a single computer

chip (integrated circuit) that executes a user program, normally for the

purpose of controlling some device hence the name microcontroller. The

program is normally contained either in a second chip, called an EPROM, or

within the same chip as the microcontroller itself. A microcontroller is

normally found in devices such as microwave ovens, automobiles,

keyboards, CD players, cell phones, VCRs, security systems, time &

attendance clocks, etc.

Microcontrollers are used in devices that require some amount of

computing power but don’t require as much computing power as that

provided by a complex (and expensive) 486 or Pentium system which

generally requires a large amount of supporting circuitry (large

motherboards, hundreds of megabytes of RAM, hard drives, hard drive

controllers, video cards, etc). A microwave oven just doesn’t need that much

computing power.

Microcontroller-based systems are generally smaller, more reliable,

and cheaper. They are ideal for the types of applications described above

where cost and unit size are very important considerations. In such

applications it is almost always desirable to produce circuits that require the

smallest number of integrated circuits, that require the smallest amount of

physical space, require the least amount of energy, and cost as little as

possible.

Microcontroller Program Storage

The program for a microcontroller is normally stored on a memory

integrated circuit (IC), called an EPROM, or on the microcontroller chip

itself. An EPROM (Electrically Programmable Read Only Memory) is a

special type of integrated circuit that does nothing more than store program

code or other data but which is maintained even when the power to the

EPROM is turned off. Once you’ve developed software for a microcontroller

it is normally programmed (or “burned”) into an EPROM chip, and that chip

is subsequently physically inserted into the circuitry of your hardware. The

microcontroller accesses the program stored in the EPROM and executes it.

Thus the program is made available to the microcontroller without the need

for a hard drive, floppy drive, or any of the other circuitry necessary to

access such devices. In recent years, more and more microcontrollers offer

the capability of having programs loaded internally into the microcontroller

chip itself. Thus, rather than having a circuit that includes both a

microcontroller and an external EPROM chip, it is now entirely possible to

have a single microcontroller which stores the program code internally.

3.2. Features of AT89C2051

· Compatible with MCS-51 Products

· 2 Kbytes of Reprogrammable Flash Memory

Endurance: 1,000 Write/Erase Cycles

· 2.7 V to 6 V Operating Range

· Fully Static Operation: 0 Hz to 24 MHz

· Two-Level Program Memory Lock

· 128 x 8-Bit Internal RAM

· 15 Programmable I/O Lines

· Two 16-Bit Timer/Counters

· Six Interrupt Sources

· Programmable Serial UART Channel

· Direct LED Drive Outputs

· On-Chip Analog Comparator

· Low Power Idle and Power Down Modes

DESCRIPTION

The AT89C2051 is a low-voltage, high-performance CMOS 8-bit

microcomputer with 2 Kbytes of flash programmable and erasable read only

memory (PEROM). The device is manufactured using Atmel’s high density

nonvolatile memory technology and is compatible with the industry

Standard MCS-51Ô instruction set and pinout. By combining a versatile 8-

bit CPU with flash on a monolithic chip, the Atmel AT89C2051 is a

powerful microcomputer which provides a highly flexible and cost effective

solution to many embedded control applications.

PIN CONFIGURATIONS

BLOCK DIAGRAM

3.3. Pin Description of AT89C2051

VCC

Supply voltage.

GND

Ground.

Port 1

Port 1 is an 8-bit bidirectional I/O port. Port pins P1.2 to P1.7 provide

internal pullups. P1.0 and P1.1 require external pullups. P1.0 and P1.1 also

serve as the positive input (AIN0) and the negative input (AIN1),

respectively, of the on-chip precision analog comparator. The Port 1 output

buffers can sink 20 mA and can drive LED displays directly. When 1s are

written to Port 1 pins, they can be used as inputs. When pins P1.2 to P1.7 are

used as inputs and are externally pulled low, they will source current (IIL)

because of the internal pullups. Port 1 also receives code data during Flash

programming and program verification.

Port 3

Port 3 pins P3.0 to P3.5, P3.7 are seven bidirectional I/O pins with internal

pullups. P3.6 is hard-wired as an input to the output of the on-chip

comparator and is not accessible as a general purpose I/O pin. The Port 3

output buffers can sink 20 mA. When 1s are written to Port 3 pins they are

pulled high by the internal pullups and can be used as inputs. As inputs, Port

3 pins that are externally being pulled low will source current (IIL) because

of the pullups. Port 3 also serves the functions of various special features of

the AT89C2051 as listed below:

Port 3 also receives some control signals for Flash programming and

programming verification.

RST

Reset input. All I/O pins are reset to 1s as soon as RST goes high. HoldingReset input. All I/O pins are reset to 1s as soon as RST goes high. Holding

the RST pin high for two machine cycles while the oscillator is runningthe RST pin high for two machine cycles while the oscillator is running

resets the device. resets the device. Each machine cycle takes 12 oscillator or clock cycles.

XTAL1

Input to the inverting oscillator amplifier and input to the internal clock

operating circuit.

XTAL2

Output from the inverting oscillator amplifier.

3.4. 212 Series of Decoders (HT12D)

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

Built-in oscillator needs only 5% resistor

Valid transmission indicator

Easy interface with an RF or an infrared transmission medium

Minimal external components

Pair with Holtek’s 212 series of encoders

GENERAL DESCRIPTION

The 212 decoders are a series of CMOS LSIs for remote control system

applications. They are paired withHoltek_s 212 series of encoders (refer to

the encoder/decoder cross reference table). For proper operation, a pair of

encoder/decoder with the same number of addresses 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 12_N bits of data. Of this series, the HT12D is

arranged to provide 8 address bits and 4 data bits.

Pin Diagram of HT12D

PIN DESCRIPTION OF HT12D

3.5. 212 SERIES OF ENCODERS (HT12E)

FEATURES

Operating voltage

o 2.4V~12V for the HT12E

Low power and high noise immunity CMOS technology

Low standby current: 0.1_A (typ.) at VDD=5V

Minimum transmission word

Four words for the HT12E

Built-in oscillator needs only 5% resistor

Data code has positive polarity

Minimal external components

Pair with Holtek_s 212 series of decoders

18-pin DIP, 20-pin SOP package

APPLICATIONS

Burglar alarm system

Smoke and fire alarm system

Garage door controllers

Car door controllers

Car alarm system

Security system

Cordless telephones

Other remote control systems

GENERAL DESCRIPTION

The 212 encoders are a series of CMOS LSIs for remote control system

applications. They are capable of encoding information which consists of N

address bits and 12_N data bits. Each address/data input can be set to one of

the two logic states. The programmed addresses/ 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 HT12E further enhances the application

flexibility of the 212 series of encoders.

PIN DIAGRAM OF HT12E

PIN DESCRIPTIONS OF HT12E

3.6. WIRELESS TRANSMITTER MODULE TX1-433.92MHZ

FEATURES:

Complete RF Transmitter Module no external components and no

tuning required.

High Performance SAW Based Architecture with a Maximum Range

of 100 feet at 4800 bps data rate.

Interface directly to Encoders and Microcontrollers with ease.

Low Power Consumption suitable for battery operated devices.

4 Pin Compact size module

Can be directly used in your PCB

Right angle Pin (Flat out) is the standard in these modules.

Optional Vertical pin out available

Can be used with Fixed Code and Rolling Code Encoders or direct

with microcontrollers

PIN DIAGRAM OF THE TRANSMITTER MODULE

PIN DETAILS OF THE TRANSMITTER MODULE

PIN 1 RF OUT

PIN 2 DATA IN

PIN 3  GROUND

PIN 4  VCC

SPECIFICATIONS

PARAMETER MINIMUM TYPICAL RANGE UNITS

Modulation method ON-OFF KEYED (OOK) Modulation (FM)

Voltage   2.7 3 5.2V DC

Supply Current    5 5.5 mA

Stand by Current     3 micro A

Output power into

50ohms    -2 0 0 dBm

Overall frequency

accuracy-250   250 KHz

Data input low 0   0.8 Volts

Data input High >0.8   Vcc Volts

Operating temp.

range0   70 Deg. Cel

Operating

frequencies433.67       433.92 434.17 MHZ

Max. Data rate     2400 bps

Antenna External1/4 Wave Whip, Helical or PCB Trace

Package SMD      

3.7. FM RECEIVER MODULE (RX-3304)

This is the radio frequency receiver module, which can facilitate the

OEM designers to design their remote control applications in remote control

in the quickest way. The circuit is designed with SMD components and the

module size is small enough to be able to be fitted in almost any application.

PIN DIAGRAM OF RECEIVER MODULE

433.92MHZ

GndR/FOUT VccVcc Gnd Ant

Gnd

PIN DETAILS OF RECEIVER MODULE

PIN 1: GND

PIN 2: Digital Output

PIN 3: Linear Output (For Testing)

PIN 4: VCC (5V DC)

PIN 5: VCC (5V DC)

PIN 6: GND

PIN 7: GND

PIN 8: ANT

 

4. CIRCUIT DESCRIPTION

4.1. Main Circuit Diagram

CIRCUIT DIAGRAM 2

4.3. CIRCUIT EXPLANATION

The Circuit consists of the transmitter and a Receiver section. The

transmitter section has encoder IC HT12E which scans the keys and convert

into analog data. This analog data was transmitted continuously through the

FM transmitter.

At the receiving end the FM signal was received by the FM receiver

and the data was decoded by the decoder IC and the decoded signal was fed

to the microcontroller and the microcontroller will control the devices

according to the received signal.

In the power supply circuit diagram we are using a 230v to 12v AC

step down transformer. The 12v ac is further Rectified with help of the four

Diodes. At the rectifier output we get an 12v DC which is filtered by the

Capacitor and the filtered 12v dc is regulated to 5v dc using the three

terminal regulator IC 7805. For the transmitter section we use a 3V battery.

5. FLOW CHART

RECEIVER SECTION

6. PROGRAM

INCLUDE reg_51.pdf

VT EQU P3.0

DATA1 EQU P3.2

DATA2 EQU P3.3

DATA3 EQU P3.4

DATA4 EQU P3.5

DEV1 EQU P1.7

DEV2 EQU P1.6

DEV3 EQU P1.5

DEV4 EQU P1.4

CSEG AT 0 ; RESET VECTOR

;---------==========----------==========---------=========---------

; PROCESSOR INTERRUPT AND RESET VECTORS

;---------==========----------==========---------=========---------

ORG 00H ; Reset

JMP MAIN

;---------==========----------==========---------=========---------

; Main routine. Program execution starts here.

;---------==========----------==========---------=========---------

MAIN:

MOV SP,#2FH

MOV P1,#0FFH

TOP: SETB VT

JB VT,$

SETB DATA1

SETB DATA2

SETB DATA3

SETB DATA4

JB DATA1,DOWN1

CPL DEV1

JNB DATA1,$

DOWN1:JB DATA2,DOWN2

CPL DEV2

JNB DATA2,$

DOWN2:JB DATA3,DOWN3

CPL DEV3

JNB DATA3,$

DOWN3:JB DATA4,DOWN4

CPL DEV4

JNB DATA4,$

DOWN4:AJMP TOP

;**********************************************************

DELAY:

MOV R1,#055H

REP2: MOV R2,#0FFH

REP1: NOP

DJNZ R2,REP1

DJNZ R1,REP2

RET

;**********************************************************

END

7. PCB DETAILS

7.1. PCB Layout

7.2. Component Layout

7.3. PCB Design

The PCB design starts right from the selection of the laminates .The

two main types of base laminate are epoxy glass and phenolic paper

laminates are generally used for simple circuits. Though it is very cheap and

can easily be drilled, phenolic paper has poor electrical characteristics and it

absorbs more moisture than epoxy glass. Epoxy glass has higher mechanical

strength.

The important properties that have to be considered for selecting the

PCB substrate are the dielectric strength ,insulation resistance,

water absorption property, coefficient of thermal expansion ,shear strength,

hardness, dimensional stability etc.

7.4 Manufacturing Process

The steps involved in manufacture are

a) Art work preparation .

b) Resist preparation .

c) Resist application an fixing .

d) Acid etch.

e) Cleaning and inspection.

f) Resist removal.

7.5. PCB Fabrication

The fabrication of a PCB basically of four steps.

a) Preparing the PCB pattern .

b) Transferring the pattern onto the PCB.

c) Developing the PCB.

d) Finishing ie) drilling, cutting, smoothing, turning etc.

Pattern designing is the primary step in fabricating a PCB in this

step, all interconnection between the components in the given circuit are

converted into PCB tracks several factors such as positioning ,the diameter

of holes ,the area that each component would occupy ,the type of end

terminal should be considered.

Transferring the PCB Pattern

The copper side of the PCB should be thoroughly cleaned with the

help of alcoholic spirit or petrol must be completely free from dust and other

contaminants.

The mirror image of the pattern must be carbon copied and to the

laminate the complete pattern may now be made each resistant with the help

of paint and thin brush.

Developing

In this developing all excessive copper is removed from the board and

only the printed pattern is left behind. About 100ml of tape water should be

heated to 75 ° C and 30.5 grams of FeCl3 added to it, the mixture should be

thoroughly stirred and a few drops of HCl may be added to speed up the

process.

The board with its copper side facing upward, should be placed in a

flat bottomed plastic tray and the aqueous solution of FeCl2 poured in the

etching process would take 40 to 60 min to complete.

After etching the board it should be washed under running water and

then held against light .the printed pattern should be cleanly visible. The

paint should be removed with the help of thinner.

Finishing Touches

After the etching is completed ,hole of suitable diameter should be

drilled ,then the PCB may be tin plated using an ordinary 35 Watts soldering

rod along with the solder core ,the copper side may be given a coat of

varnish to prevent oxidation.

Drilling

Drills for PCB use usually come with either a set of collects of various

sizes or a 3-Jaw chuck. For accuracy however 3-jaw chunks aren’t brilliant

and small drill below 1 mm from grooves in the jaws preventing good grips.

Soldering

Begin the construction by soldering the resistors followed by the

capacitors and the LEDs diodes and IC sockets. Don’t try soldering an IC

directly unless you trust your skill in soldering. All components should be

soldered as shown in the figure. Now connect the switch and then

solder/screw if on the PCB using multiple washers or spaces. Soldering it

directly will only reduce its height above other components and hamper in

its easy fixation in the cabinet. Now connect the battery lead.

Assembling

The circuit can be enclosed in any kind of cabinet. Before fitting the

PCB suitable holes must be drilled in the

cabinet for the switch, LED and buzzer. Note that a rotary switch can be

used instead of a slide type.

Switch on the circuit to be desired range. It will automatically start its timing

cycles. To be sure that it is working properly watch the LED flash. The

components are selected to trigger the alarm a few minutes before the set

limit.

8. ESTIMATION

Sl.No Component Name Number Quantity Price

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

Microcontroller

Encoder IC

Decoder IC

FM transmitter module

FM receiver module

Antenna

Battery

SIP

Resistors

Capacitor

Crystal

PCB Designing

PCB Fabrication

Microcontroller Programming

AT89C2051

HT12E

HT12D

_

-

9V

10K

-

-

12 MHZ

-

-

-

-

2

1

1

1

1

1

1

1

6

2

2

-

-

-

400

250

300

250

300

50

25

20

5

50

50

250

250

700

Total Rs. 3400-00

9. CONCLUSION

The Construction and testing of all parts of the project have been

successfully completed. Through this project we have learned how to face a

new project work. This system can be used in factories, home etc. so that the

we can control devices from a distant place using this system. This system

can be adopted to control any kind of devices such us fan, light, Motor etc

10. BIBLIOGRAPHY

1. THE 8051 MICROCONTROLLER AND EMBEDDED

SYSTEMS -By Muhammed Ali Mazidi , Janice Gillispie Mazidi

2. COMMUNICATION SYSTEMS –By B. Sharma

3. WWW.ATMEL.COM

4. WWW.DALSEMI.COM

5. WWW.MICROCONTROLLER.NET

6. WWW.8052.COM