Project Report Sample

Mini Project’11 DTMF Based Fire Extinguisher

Dept. Of ECE IESCE, Thrissur

ACKNOWLEDGEMENT

We take this opportunity to thank GOD almighty, for blessing us with grace throughout

this project and take our endeavour to a successful culmination.We are extending our sincere and

heartfelt gratitude to our Project Guide Mrs.RACHANA.M.K , the lecturer of Electronics And

Communication Engineering and Mrs.REKHA M, the Project co-ordinator of Electronics And

Communication Engineering. We intend our prodigious thanks to our Principal,

Dr.VEERANKUTTY,the head of the Department of Electronics And Communication

Engineering Prof.SHIJU ARAVINDAKSHAN.M for encouraging and allowing us to make use

of facilities over here and thus completing our project.

We would like to thank our faculty members also on this occasion. Last but not the least

we would like to thank our companions for the support and encouragement they have extended

to us during the course of work.



ABSTRACT

A method used by the telephone system to recognize the keys pressed when dialing.

Pressing a key on the phone's keypad generates two simultaneous tones, which are decoded by

the exchange to determine which key was pressed.

The full form of DTMF is dual tone multi frequency it is being used when u want to send

u tone of a number to the opponent like in the voice recording when u call to customer service

there is a tone recognizer which will get the tone of the number which u have press and do the

functionality Dual-tone-multi-frequency (DTMF, also known as touch-tone) are the audible

sounds you hear when you press keys on your phone. Touch-tone is familiar to many

(telephone), it is a mature technology, and readily available with off-the-shelf, single-chip, low-

cost components

A DTMF based fire extinguisher system is based on extinguishing fire by controlling the

circuit direction through phone. Here we use integrated with digital decoder and band split filter

functions. A DTMF keypad consists of numbers with varying frequency. The generated tone at

the transmitter is decoded by the decoder which is placed in the circuit the transmitter is the

mobile phone. it pumps the water by viewing through the camera where the fire had struck and

water it in the direction where the fire had struck



CONTENTS

LIST OF FIGURES I

LIST OF ABBREVIATIONS II

1. INTRODUCTION 1

2. BLOCK DIAGRAM 4

3. BLOCK DIAGRAM DESCRIPTION 5

3.1 MICROCONTROLLER 5

3.2 MOBILE PHONES 6

3.3 DTMF DECODER 6

3.4 TEMPERATURE SENSOR 7

3.5 CENTRIFUGAL PUMP 8

3.6 DRIVERS 8

3.7 MOTORS 9

4. CIRCUIT DIAGRAM 10

5. CIRCUIT DIAGRAM EXPLANATION 11

5.1 MICROCONTROLLER 11

5.2 TEMPERATURE SENSOR 19

5.3 DTMF DECODER 19

5.4 DRIVER 20

6. WORKING OF CIRCUIT 21

7. PCB LAYOUT 22



8. FIRMWARE 23

9. ADVANTAGES AND DISADVANTAGES 25

9.1 ADVANTAGES 25

9.2 DISADVANTAGES 25

10. APPLICATIONS 26

11. FUTURE ENHANCEMENT 29

12. CONCLUSION 30

13. REFERENCE 31

14. APPENDIX 32


Dept. Of ECE I IESCE, Thrissur

LIST OF FIGURES

TITLE PAGE NO

Block Diagram of DTMF based fire extinguisher 4

Circuit Diagram Of DTMF BASED fire extinguisher 10

Block Diagram of PIC 16F677A 13

Block Diagram of RA3:RA0 Pins 14

Block Diagram of RB3:RB0 Pins 15

Block Diagram of PORTC 16

Block Diagram of PORTD 17

Block Diagram of PORTE 18

DTMF Keypad 19

PCB Layout 22


Dept. Of ECE II IESCE, Thrissur

LIST OF ABBREVIATIONS

NAME FULL FORM

A/D Analog to Digital Converter

BOR Brown-out Reset

DC Direct current

DTMF Dual Tone Multiple Frequency

EEPROM Electrically Erasable Programmable read only memory

ICSP In-Circuit Serial Programming

MC Microcontroller

μA Micro ampere

PC Personal Computer

PCB Printed Circuit Board

PIC Peripheral Interface Controller

WDT Watchdog Timer

Mini Project ‘11 DTMF Based Fire Extinguisher

Dept. Of ECE 1 IESCE, Thrissur

1. INTRODUCTION

Dual-tone-multi-frequency (DTMF, also known as touch-tone) are the audible sounds

you hear when you press keys on your phone. Touch-tone is familiar to many (telephone), it is a

mature technology, and readily available with off-the-shelf, single-chip, low-cost components A

method used by the telephone system to recognize the keys pressed when dialing. Pressing a key

on the phone's keypad generates two simultaneous tones, which are decoded by the exchange to

determine which key was pressed. For these reasons DTMF is often used in remote control

applications that typically use telephones. The DTMF (Dual Tone Multiple Frequency)

application is associated with digital telephony, and provides two selected output frequencies

(one high band, one low band) for duration of 100 ms.

Yet another experiment is to interface either the generator or the emitter or both to a PC

or embedded microprocessor (e.g. 8051, PIC or Stamp). In this scenario, the PC or a peripheral,

through touch-tones, can respond and controlIn DTMF there are 16 distinct tones. Each tone is

the sum of two frequencies: one from a low and one from a high frequency group. There are four

different frequencies in each group. Your phone only uses 12 of the possible 16 tones. If you

look at your phone, there are only 4 rows (R1, R2, R3 and R4) and 3 columns (C1, C2 and C3).

The rows and columns select frequencies from the low and high frequency group respectively.

. The bottom line is that DTMF was designed for optimal performance with each tone

being very distinct. This makes decoding the tone very easy even in surrounding noise. It is this

performance that makes DTMF ideal for clear transmission and reception in remote control

(wireless or through phone lines) applications. DTMF decoder can be powered from a 9V battery

or from your parallel printer port. It can detect and display all 16 DTMF digits on your computer



screen in real-time. The Window's program can be placed in the minimize mode and still detect

tones while you use your computer to do other things like Net surfing

The tone generator's speaker next to the mouthpiece of your phone, and dialling a phone

number might actually work since the emitted tone is loud enough. remote control unit has 4

channels which can be easily extended to 12. This circuit differs from similar circuits in view of

its simplicity and a totally different concept of generating the control signals. Usually remote

control circuits make use of infrared light to transmit control signals. Their use is thus limited to

a very confined area and line-of-sight.

DTMF can be used to switch up to nine appliances (corresponding to the digits 1 through

9 of the telephone key-pad). The DTMF signals on telephone instrument are used as control

signals. The digit ‘0’ in DTMF mode is used to toggle between the appliance mode and normal

telephone operation mode. Thus the telephone can be used to switch on or switch off the

appliances also while being used for normal conversation

Telephone intercom version of the Link uses DTMF tones for dialling both internally

between handsets, and externally for outside calls. Remember, in some countries, it is to simply

connect unapproved and untested equipment to Telco lines, so avoid the fine and confiscation of

your equipment, and the link has only 2 handsets, numbered 1 and 2. When the Link is at reset,

both phones are on hook and no external incoming call is present. All chips run off a +5 V

regulator and all relays and telephone handsets run off a +12 V regulator

A DTMF Decoder displays telephone numbers decoded from tones. A microphone picks

up the tones, a preamplifier boosts the signals. DTMF chip decodes the tones, a Basic Stamp acts

as an interface to an LCD display and also provides serial output. The HT9170 series are Dual

Tone Multi Frequency (DTMF) receivers integrated with digital decoder and band split filter

functions. The HT9170B and HT9170D types supply power-down mode and inhibit mode



operations. All types of the HT9170 series use digital counting techniques to detect and decode

all the 16 DTMF tone pairs into a 4-bit code output. Highly accurate switched capacitor filters

are employed to divide tone (DTMF) signals into low and high group signals. A built-in dial tone

rejection circuit is provided to eliminate the need for pre-filtering.

In most cases the consequences faced are irrepairable. The possibility of occurrence of

fire is high now a days. So fire detectors are inevitable role in every field. Ordinary fire detectors

are only meant for detecting fire There are detectors which can detect possibility of fire and can

extinguish it in a parallel manner before having its own vital impact.

A DTMF based fire extinguisher system is based on extinguishing fire by controlling the

circuit direction through phone. Here we use integrated with digital decoder and band split filter

functions. A DTMF keypad consists of numbers with varying frequency. The generated tone at

the transmitter is decoded by the decoder which is placed in the circuit the transmitter is the

mobile phone. it pumps the water by viewing through the camera where the fire had struck and

water it in the direction where the fire had struck



2. BLOCK DIAGRAM

DTMF

MODULE

PIC GSM

MODULE

DC

MOTOR

CENTRIFUGAL

PUMP

POWER SUPPLY

TEMP

SENSOR

BUZZER PC CAMERA



3. BLOCK DIAGRAM DESCRIPTION

The microcontroller controls the entire operations. Here we use PIC 16F877A to control

the device. The system also consist DTMF decoder, H Bridge, DC motors, centrifugal pump,

driver and temperature sensor. The temperature sensor senses the ambient temperature and

provides output voltage in accordance with the temperature. LM35 is used as the temperature

sensor. The output of the sensor is connected to the analog channel of the microcontroller. The

microcontroller is programmed to turn on the buzzer according to the temperature level.

3.1 MICROCONTROLLER

Microcontroller (MC) is a small computer on a single integrated circuit containing a

processor core, memory, and programmable input/output peripherals. Program memory in the

form of NOR flash or OTP ROM is also often included on chip, as well as a typically small

amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the

microprocessors used in personal computers or other general purpose applications.

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

automobile engine control systems, implantable medical devices, remote controls, office

machines, appliances, power tools, and toys. By reducing the size and cost compared to a design

that uses a separate microprocessor, memory, and input/output devices, microcontrollers make it

economical to digitally control even more devices and processes. Mixed signal microcontrollers

are common, integrating analog components needed to control non-digital electronic systems.



3.2 MOBILE PHONES

Mobile phones are electronic device used for full duplex two-way radio

telecommunications over a cellular network of base stations known as cell sites. Mobile phones

differ from cordless telephones, which only offer telephone service within limited range through

a single base station attached to a fixed land line, for example within a home or an office. Low-

end mobile phones are often referred to as feature phones, whereas high-end mobile phones that

offer more advanced computing ability are referred to as smart phones.

A mobile phone allows its user to make and receive telephone calls to and from the

public telephone network which includes other mobiles and fixed line phones across the world. It

does this by connecting to a cellular network owned by a mobile network operator. A key feature

of the cellular network is that it enables seamless telephone calls even when the user is moving

around wide areas via a process known as handoff or handover.

3.3 DTMF DECODER

Dual-tone multi-frequency signal (DTMF) is used for telecommunication signaling over

analog telephone lines in the voice-frequency band between telephone handsets and other

communications devices and the switching center. The version of DTMF that is used in push-

button telephones for tone dialing is known as Touch-Tone, was first used by AT&T in

commerce as a registered trademark, and is standardized by ITU-T Recommendation Q.23. It is

also known in the UK as MF4.

Other multi-frequency systems are used for internal signaling within the telephone

network. The Touch-Tone system, using the telephone keypad, gradually replaced the use of

rotary dial starting in 1963, and since then DTMF or Touch-Tone became the industry standard

for both cell phones and landline service



3.4 TEMPERATURE SENSOR

The LM35 series are precision integrated-circuit temperature sensors, whose output

voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an

advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to

subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The

LM35 does not require any external calibration or trimming to provide typical accuracies of

±¼°C at room temperature and ±¾°C over a full -55 to +150°C temperature range. Low cost is

assured by trimming and calibration at the wafer level. The LM35's low output impedance, linear

output, and precise inherent calibration make interfacing to readout or control circuitry especially

easy. It can be used with single power supplies, or with plus and minus supplies. As it draws

only 60 µA from its supply, it has very low self-heating, less than 0.1°C in still air. The LM35 is

rated to operate over a -55° to +150°C temperature range, while the LM35C is rated for a -40° to

+110°C range (-10° with improved accuracy). The LM35 series is available packaged in

hermetic TO-46 transistor packages, while the LM35C, LM35CA, and LM35D are also available

in the plastic TO-92 transistor package. The LM35D is also available in an 8-lead surface mount

small outline package and a plastic TO-220 package.

Features

Calibrated directly in ° Celsius (Centigrade)

Linear + 10.0 mV/°C scale factor

0.5°C accuracy guaranteeable (at +25°C)

Rated for full -55° to +150°C range

Suitable for remote applications

Low cost due to wafer-level trimming

Operates from 4 to 30 volts



Less than 60 µA current drain

Low self-heating, 0.08°C in still air

Nonlinearity only ±¼°C typical

Low impedance output, 0.1 Ohm for 1 mA load

3.5 CENTRIFUGAL PUMP

A centrifugal pump is a rotodynamic pump that uses a rotating impeller to increase the

pressure of a fluid. Centrifugal pumps are commonly used to move liquids through a piping

system. The fluid enters the pump impeller along or near to the rotating axis and is accelerated

by the impeller, flowing radially outward into a diffuser or volute chamber (casing), from where

it exits into the downstream piping system. Centrifugal pumps are used for large discharge

through smaller heads.

3.6 DRIVERS

A driver typically communicates with the device through the computer bus or

communications subsystem to which the hardware connects. When a calling program invokes a

routine in the driver, the driver issues commands to the device. Once the device sends data back

to the driver, the driver may invoke routines in the original calling program. Drivers are

hardware-dependent and operating-system-specific. They usually provide the interrupt handling

required for any necessary asynchronous time-dependent hardware



3.7 MOTORS

Motor is a device that creates motion. It usually refers to an engine of some kind DC

motor, an electric motor that runs on direct current electricity Brushed DC electric motor, an

internally commutated electric motor designed to be run from a direct current power source

Brushless DC motor, a synchronous electric motor which is powered by direct current electricity

and has an electronically controlled commutation system, instead of a mechanical commutation

system based on brushes The brushed DC motor generates torque directly from DC power

supplied to the motor by using internal commutation, stationary permanent magnets, and rotating

electrical magnets.It works on the principle of Lorentz force , which states that any current

carrying conductor placed within an external magnetic field experiences a torque or force known

as Lorentz force. Advantages of a brushed DC motor include low initial cost, high reliability, and

simple control of motor speed. Disadvantages are high maintenance and low life-span for high

intensity uses.



4.CIRCUIT DIAGRAM



5. CIRCUIT DIAGRAM EXPLANATION

5.1 MICROCONTROLLER

Heart of the circuit is a microcontroller. The microcontroller used here is the PIC

16F877A. PIC is a family of Harvard architecture microcontrollers made by Microchip

Technology, derived from the PIC1640 originally developed by General Instrument'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.

hle 5.1.1 FEATURES OF PIC MICROCONTROLLER

High-Performance RISC CPU:

Only 35 single-word instructions to learn

All single-cycle instructions except for program

branches, which are two-cycle

Operating speed: DC – 20 MHz clock input

Universal Synchronous Asynchronous Receiver

Transmitter (USART/SCI) with 9-bit address

Detection



Analog Features:

10-bit, up to 8-channel Analog-to-Digital

Converter (A/D)

Brown-out Reset (BOR)

Analog Comparator module

Special Microcontroller Features:

100,000 erase/write cycle Enhanced Flash

program memory typical

1,000,000 erase/write cycle Data EEPROM

memory typical

Data EEPROM Retention > 40 years

Self-reprogrammable under software control

In-Circuit Serial Programming™ (ICSP™)

via two pins

Single-supply 5V In-Circuit Serial Programming

Watchdog Timer (WDT) with its own on-chip RC

oscillator for reliable operation



5.1.2 BLOCK DIAGRAM OF PIC 16F877A



5.1.3 PORTA AND THE TRISA REGISTER

Fig: Block diagram of RA3:RA0 PINS

PORTA is a 6-bit wide, bidirectional 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 High-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 operations. 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. Pin RA4 is multiplexed with the Timer0 module clock input to become the

RA4/T0CKI pin. The RA4/T0CKI pin is a Schmitt Trigger input and an open-drain output.

5.1.4 PORTB AND THE TRISB REGISTER

Fig: Block diagram RB3:RB0 pins



PORTB is an 8-bit wide, bidirectional 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 High-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).Three pins of PORTB are multiplexed with the In-Circuit Debugger and

Low-Voltage Programming function: RB3/PGM, RB6/PGC and RB7/PGD. Each of the

PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This

is performed by clearing bit RBPU (OPTION_REG<7>). The weak pull-up is automatically

turned off when the port pin is configured as an output.

5.1.5 PORTC AND THE TRISC REGISTER

Fig: Block diagram of PORT C



PORTC is an 8-bit wide, bidirectional 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 High-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 When enabling

peripheral functions, care should be taken in defining TRIS bits for each PORTC pin. Some

peripherals override the TRIS bit to make a pin an output, while other peripherals override the

TRIS bit to make a pin an input.

5.1.6 PORTD AND THE TRISD REGISTERS

Fig: Block diagram of PORT D



PORTD is an 8-bit port with Schmitt Trigger input buffers. Each pin is individually

configurable as an input or output. PORTD can be configured as an 8-bit wide microprocessor

port (Parallel Slave Port) by setting control bit, PSPMODE (TRISE<4>). In this mode, the

input buffers are TTL.

5.1.7 PORTE AND THE TRISE REGISTER

PORTE has three pins (RE0/RD/AN5, RE1/WR/AN6 and RE2/CS/AN7) which are

individually configurable as inputs or outputs. These pins have Schmitt Trigger input buffers.

The PORTE pins become the I/O control inputs for the microprocessor port when bit

PSPMODE (TRISE<4>) is set. In this mode, the user must make certain that the TRISE<2:0>

bits are set and that the pins are configured as digital inputs. Also, ensure that ADCON1 is

configured for digital I/O. In this mode, the input buffers are TTL.

Fig: Block diagram of PORT E



5.2 TEMPERATURE SENSOR

The LM35 has an advantage over linear temperature sensors calibrated in ° Kelvin, as

the user is not required to subtract a large constant voltage from its output to obtain convenient

Centigrade scaling. The LM35 does not require any external calibration or trimming to provide

typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C

temperature range. Low cost is assured by trimming and calibration at the wafer level. The

LM35’s low output impedance, linear output, and precise inherent calibration make interfacing

to readout or control circuitry especially easy. It can be used with single power supplies, or

with plus and minus supplies. As it draws only 60 μA from its supply, it has very low self-

heating, less than 0.1°C in still air. The LM35 is rated to operate over a −55° to +150°C

temperature range.

5.3 DTMF DECODER

The HT9170 series are Dual Tone Multi Frequency (DTMF) receivers integrated

with digital decoder and band split filter functions. All types of the HT9170 series use digital

counting techniques to detect and decode all the 16 DTMF tone pairs into a 4-bit code output.

Highly accurate switched capacitor filters are employed to divide tone (DTMF) signals into

low and high group signals.

Fig: DTMF keypad



Fig: DTMF frequency table

5.4 DRIVER

A transistor is used to drive the centrifugal pump, since the microcontroller can not

drive it directly. Here we use BC 548 to drive the pump.



6. WORKING OF THE CIRCUIT

As in every embedded system, the microcontroller controls all operations. Here we use

PIC 16F877A and LM35 is used as the temperature sensor. The temperature sensor senses the

ambient temperature and provides output voltage in accordance with the temperature. The

output of the sensor is connected to the analog channel of the microcontroller. When the

temperature is above a critical level, the buzzer makes an annoyance and controller watches the

input port to get signal from the DTMF IC. The HT9170 series are Dual Tone Multi Frequency

(DTMF) receivers integrated with digital decoder and band split filter functions. We can view

the fire through a camera connected to the PC. This camera is placed on the DC Motor, which is

controlled by the GSM device.

The keys 4 and 6 are used to rotate the DC Motor in either directions. The key 5 is used

for pumping water and key 2 is used to halt all the functions.



7. PCB LAYOUT



8. FIRM WARE

#include <htc.h>

#ifndef _XTAL_FREQ

// Unless already defined assume 4MHz system frequency

// This definition is required to calibrate __delay_us() and __delay_ms()

#define _XTAL_FREQ 16000000

#endif

#define BUTTON1 RB0 //bit 1 of PORTB




main(void)

{

//unsigned char i, j;

TRISD = 0; /* all bits output */

TRISB = 0xFF;

while(1)

{

if((BUTTON1 == 0)&&(BUTTON2 == 1)&&(BUTTON3 == 0)&&(BUTTON4 == 0)) /* if switch pressed, increment */

{



RD0 = 0;

RD1 = 1;

RD2 = 0;

}

else if((BUTTON1 == 0)&&(BUTTON2 == 1)&&(BUTTON3 == 1)&&(BUTTON4 == 0)) /* if switch pressed, increment */

{

RD0 = 1;

RD1 = 0;

RD2 = 0;

}

else if((BUTTON1 == 0)&&(BUTTON2 == 1)&&(BUTTON3 == 0)&&(BUTTON4 == 1)) /* if switch pressed, increment */

{

RD0 = 0;

RD1 = 0;

RD2 = 1;

}

else

{

RD0 = 0;

RD1 = 0;

RD2 = 0;

}}}



9. ADVANTAGES AND DISADVANTAGES

9.1 ADVANTAGES

Proximity sensing can be done in an easier manner.

Many devices can be controlled at a time using DTMF alone.

The havocs due to fire can be reduced

Using phone various things can be done at a time.

DTMF alone can be used as an object counter, tachometer and intruder alarms by

assigning various functions to numbers in phone.

Cost effective

In industries and buildings controlling and sensing can be done easily.

Many persons can access this by simply calling.

9.2 DISADVANTAGES

The frequency range is limited.

It’s not fully automatic.

The range of mobile is a problem because only by calling the pumping of water can be

done.

Many persons can access which may lead to misleading.



10. APPLICATIONS

DTMF finds applications in

Burglar alarms:- Burglar (or intrusion), fire, and safety alarms are electronic alarms

designed to alert the user to a specific danger. Sensors are connected to a control unit via

low-voltage wiring or a narrowband RF signal which is used to interact with a response

device. The most common security sensors are used to indicate the opening of a door or

window or detect motion via passive infrared (PIR)

.

Object counter :- A system for counting the number of objects of known thickness in a

stack and identifying the objects by their color in which an ultrasonic sensor is mounted

at a known distance from a reference point that defines the beginning of the stack. The

ultrasonic sensor is operated to measure the round trip transit time of ultrasonic energy

reflected back from the closest object in the stack and the number of objects in the stack

is calculated on the basis of the known distance and the round trip transit time. A color

sensor senses the color of at least one object in the stack to identify the object. In a casino

application where the objects are chips of known monetary value, the value of the chips

in the stack can be calculated.

Tachometers:- A tachometer (also called a revolution-counter, rev-counter, or RPM

gauge) is an instrument that measures the rotation speed of a shaft or disk, as in a motor

or other machine. The device usually displays the revolutions per minute (RPM) on a

calibrated analogue dial, but digital displays are increasingly common.

Proximity sensing of mobile robots:- A DTMF-based IR transmitter and receiver pair

can be used to realize a proximity detector. This enables us to detect any object capable

of reflecting the IR beam and moving in front of the IR LED photo detector pair up to a

distance of about 12 cm from it.



Used to detect the presence of human beings:-DTMF consists of different tones for

different frequencies. So in order to detect the presence of human beings DTMF is used.

The intruders will be detected while cutting the IR rays. Thereby the buzzer produces the

sound and point out the intruders easily.

To control electric appliances:-Using DTMF the electric appliances can be controlled

thereby using it for proximity detection. By assigning different frequencies for different

numbers different appliances can controlled using remote control.

Sensor mechanical construction applications:- Various mechanical construction of

sensors can be controlled using the DTMF .The frequency can be controlled using

DTMF. Hence the distance of operation can be noted.

DTMF Based Fire Extinguisher finds application in

This is ideal for remote control applications around your home, office, shop:- Fire

can create a disaster .A small fire can even make a city to barren land and thereby take

away millions of lives. So by using this circuit the wireless camera in the circuit will

identify the direction where the fire had struck.. Automatic answering of call will make

the circuit to pump water and water it to the direction specified. The direction can be

directed by pressing keys on the mobile phone.

Proximity sensing of mobile robots: - The proximity sensing of robots can be done by

using phones via DTMF. The proximity sensing can be done by adjusting the frequency

through DTMF. By assigning various functions to various numbers at different

frequencies make it available for proximity sensing of mobile robots. we can make it do

whatever the jobs we want by pressing that assigned numbers in mobile phones.



Industrial application: - DTMF can be used for making various types of machines to

work at a time. It can be controlled using DTMF. A wireless camera is attached in the

circuit. This makes us available to watch using USB TV Stick that is installed in PC. In

chemical factories the amount of addition of various constituents can be noted. Also in

every industries the security can be assigned, speed of rotation of machines can be noted

easily using DTMF.



11. FUTURE ENHANCEMENT

The circuit can be employed for Robotics.

Using wireless camera and PC we can locate the region easily

Sand and Hydrogen peroxide can be used instead of water in heavy

machinery manufacturing units and so on..

The range of operation can be increased by using relays.

Display placed at specified areas makes the current incidents known to every

one.

By placing more than one DTMF in the circuit double number of devices can

be controlled and sensed at a time.

The direction of tracking of fire can be increased by making changes in firm

ware.

The USB TV stick installed in their PC makes everyone to view current

incidents at the same time.



12. CONCLUSION

As a part of our project we studied the various aspects related with microcontroller.

Design of reliable and cost efficient fire extinguisher system begins with the establishing of

need through system planning. It then progress through a conceptual design that balances

reliability, ultimate development and cost and culminates in detailed design through firmware.

The project involves a DTMF based fire extinguisher which pumps the water following

the automatic answering of call, camera will determine the direction where the fire has struck.

We cn also watch the presence using USB TV stick that can be installed in PC. The direction

can be controlled using mobile phone and can water it to that direction where the fire has

struck. Thus the havocs due to fire can be reduced.



13. REFERENCE

1. Ajay V Desmukh – ‘Microcontrollers – Theory And Applications’

2. www.microchip.com

3. www.national.com

4. Balaguruswamy –Programming in ANSI C

http://www.national.com/



APPENDIX

Documents

Project Report Sample