1. PROJECT PRESENTATION ON GSM BASED GAS LEAKAGE DETECTION SYSTEM
TEAM MEMBERS:
K Yasodha NM1A0468
K Mounika NM1A0475
K Snehaja NM1A0471
N Roja Kumari NM1A04A7
PROJECT GUIDE
Prof.v.s.v .Ranga Das

2. INTRODUCTION
The aim of this project is to automatically detect and stop gas leakage in vulnerable premises.
Gas leakage detection is the process of identifying hazardous gas leaks by means of various sensors.
These sensors usually employ an audible alarm to alert people when a dangerous gas has been detected.
The total circuit is arranged on a bread board.

3. BLOCK DIAGRAM LCD GSM module Micro controller AT89C51 Stepper motor
Main
Power
Supply
ULN 2003
Driver IC
MQ 6
Gas sensor
Stepper motor
Main Gas Supply
ULN2003
Driver IC
Alarm unit
LCD

4. COMPONENTS USED IN THIS PROJECT
AT89S51 microcontroller
Gas sensor-MQ6
ULN2003 driver
Stepper motors
GSM module
Buzzer
Power supply

5. AT89S51 Microcontroller
The AT89S51 is a low-power, high-performance CMOS 8-bit micro controller with 8Kbytes of in-system programmable Flash memory.
It is a 40 pin device.
This device is compatible with the industry-standard 80C51 micro controller.
By combining a versatile 8-bit CPU with in-system programmable flash one monolithic chip; the Atmel AT89S51 is a powerful micro controller, which provides a highly flexible and cost-effective solution to many embedded control applications.

6. GAS SENSOR
A GAS SENSOR is an electronic device which Detects dangerous gas leaks in the industrial areas.
This unit detects 300 to 5000ppm of Natural Gas.
Good sensitivity to Combustible gas in wide range.
High sensitivity to Propane, Butane and LPG.
Long life and low cost.
Simple drive circuit.

7. ULN2003 DRIVER
The ULN 2003 is high-voltage, high-current Darlington driver comprised of seven NPN Darlington pairs.
The collector-current rating of a single Darlington pair is 500 mA. The Darlington pairs can be paralleled for higher current capability.
ULN2003 is commonly used to interface with  Stepper Motors.
It can withstand peak current of 600mA.

8. ULN2003 WITH STEPPER MOTOR
INTERNAL DIAGRAM:

9. Stepper motor
Motors convert electrical energy into mechanical energy.  A stepper motor converts electrical pulses into specific rotational movements.
A stepper motor is a brushless DC electric motor that divides a full rotation into a number of equal steps.
Stepper motors work on the principle of electromagnetism

10. GSM MODULE
A GSM module is used to send an sms to the user cell phone, when the gas leakage is detected by the gas sensor. Micro controller sends a signal to the gsm module in which one of the tasks is to send the text sms.
Gsm module requires one sim card and is capable to accept any type of network. It works with 12v dc supply.
It has a unique identity number like our mobile phones have .With the help of gsm we can send sms and also send a voice message. These messages are saved in the micro controller memory.

11. BUZZER
A buzzer or beeper is a audio signaling device, usually electronic, typically used in automobiles, household appliances such as a microwave oven, or game shows .

12. OPERATION OF THE CIRCUIT
First we have to apply 9v dc to the Vcc pin of the microcontroller.
The reset pin is used to clear all the values of temporary register of microcontroller.
Crystal oscillator is connected between the 18,19 pins of the microcontroller here the crystal frequency is mhz.
The ULN2003 driver is used as h-bridge and also as a current amplifying ic to increase the power to drive the motor.
Here we use two side shaft dc motor to wheels with 300rps and the power to the motors is from the ULN2003.
The microcontroller AT89S51 is used to control the total system by its internal program code.
When we press the reset button the dc motors starts and travel its predefined area and when gas is detected by the sensor then the buzzer is starts buzzing and motors will stop until we press the reset button.

13. APPLICATIONS
This project is applicable in following fields: 1. Gas leakage detector (Domestic) 2. Combustible gas detector (Industrial) 3. Gas detector (Portable) 4. Homes 5. Factories 6. LPG storage 7. Hotels etc.

14. Advantages: Low power consumption and reliable.
The advantage this has over others is that it provides quick response rate and has faster diffusion of the critical situation than the manual methods.
All the reviewed works aimed at developing systems capable of detecting gas leakages and sending an SMS alert to the user. 
The system enables monitoring of gas leakages in remote locations and thereby leads to a faster response time in the events of a leakage condition.

15. References:

16. SOME GAS LEAKAGE SITUATIONS

19. CONCLUSION
This project is microcontroller based project. A Gas sensor is used to detect dangerous gas leaks in the kitchen or near the gas heater. Ideal to detect dangerous gas leaks in the kitchen.
The sensor can also sense LPG and Coal Gas as well as Ideal sensor for use to detect the presence of a dangerous LPG leak in your car or in a service station, storage tank environment.
This unit can be easily incorporated into an alarm unit, to sound an alarm or give a visual indication of the LPG concentration.
The sensor has excellent sensitivity combined with a quick response time.