3. INTRODUCTION
The presence of dangerous LPG leakage in the
homes can be detected using the Ideal Gas
Sensor.
This unit can be easily integrated into a unit that
can sound an alarm or make a call on your
mobile.
It can also turn off the power supply of our home.
The sensor can also sense iso-butane,
propane,LNG and cigarette smoke.
5. BLOCK DIAGRAM
DESCRIPTION
MQ-5 LPG SENSOR : It senses the leakage of
LPG. The out put of this sensor is high at normal
condition. The output goes low, when it senses
the LPG.
MICROCONTROLLER: It is the whole control of
the project. It controls the Exhaust fan, LED and
Buzzer when LPG leak occurs. The input/ output
ports of the microcontroller is used for this.
EXHAUST FAN : This is used to send out the
LPG to space and then the concentration of LPG
is reduced.
6. Buzzer : When buzzer is blowing, this indicates
the leakage of LPG gas. It is 12 V DC operated
buzzer.
LED : When LED is glowing, this indicates the
leakage of LPG gas. It is 1.2 V DC operated LED.
7. WORKING
The output of the sensor goes LOW as soon as
the LPG sensor senses any gas leakage from the
storage.
This is detected by the microcontroller and gives
direction to make a call using GSM Module and to
turn off the power supply using by power control
unit.
MQ-5 semiconductor sensor is Combustible Gas
Sensitive. The MQ-5 gas sensor is made up of
SnO2 which has lower conductivity in clean air
A simple electro-circuit is used here which is used
to convert the changing conductivity into
corresponding output signal of gas concentration
8. Methane and Propane can be detected easily by
MQ-5 sensor because it has high sensitivity
towards Methane, Propane and Butane.
It is a low cost sensor suitable for different
application.
9. start
Power On
MCU sends’AT’ to
GSM Module
GSM
module
replies
“OK”
Is sensors o/p
value is greater
than threshold
value ?
Turn on LED & buzzer
Start Exaust fan
Send message to stored
mobile no.
No
Yes
No
Ye
s
FLOW CHART
10. CONNECTION BETWEEN
MICROCONTROLLER & GSM
MODULE
For connection, connect Receiver Pin (Rx) of
Microcontroller to Transmitter Pin (Tx) of GSM
Module and Transmitter Pin (Tx) of
Microcontroller to Receiver Pin (Rx) of GSM
Module.
AVR GSM
Rx Tx
Tx
Vcc Vcc
11. ADVANTAGES
Detection and prevention of any sort of gas
leakage.
Cost efficient.
Less complex circuit.
No environmental effect or no effect of physical
conditions.
12. APPLICATION
Domestic gas leakage detector
Homes
Portable gas detector
factories
Industrial Combustible gas detector
Lpg storage
Gas car
13. CONCLUSION
The previous listed applications of this GSM
based security system are based on the fact that
this system is able to detect any sort of gas
leakage.
In case there is a gas leakage in a house,hotel or
in a laboratory, this security system will
simultaneously complete two tasks Firstly it will
turn off the power supply, secondly it will connect
a call to the predefined number listed in the
program.
Due to this simultaneous action accidents can be
prevented.
