This document describes a gas leakage detection and alert system using an Arduino board. The system uses an LPG gas sensor to detect gas leaks and triggers an alarm with lights and sounds. If a leak is detected, it will also send an alert via Bluetooth. It is designed for home safety to prevent accidents from gas leaks in the kitchen. When fully built, the system will help prevent accidents and can be enhanced for industrial use.

2. OBJECTIVES OF THE PROJECT
• Detect Gas Leakage (like LPG) using LPG Gas Sensor and
Arduino.
• Sound Alarm - produce sound alert on gas leak.
• Glow an Emergency LED light.
• Setup an Bluetooth based Alert Mechanism using a
Bluetooth Module.

3. COMPONENTS
 Arduino Uno
 LPG gas sensor module
 2 LEDs
 Buzzer
 1k Resistors
 Bread board
 Jumper Wires
 Bluetooth module HC-05

4. BLOCK DIAGRAM DESCRIPTION
• MQ-5 LPG SENSOR
To sense LPG (use Analog Out to detect level
status)
• ARDUINO UNO
i)To read MQ5 output and detect Gas Leak (through level
comparison).
ii)To activate outputs upon gas leak – sound alarm and LED
blinking.
iii)To send alert commands to bluetooth module HC-05.
• 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

5. DETECTION SYSTEM
 GAS DETECTOR UNIT MQ-05
 THE OUTPUT OF THIS SENSOR IS “HIGH” AT
NORMAL CONDITION. THE OUTPUT GOES LOW,
WHEN IT SENSES THE LPG.

6. CONTROL UNIT
 ARDUINO UNO -BRAIN OF THE WHOLE SETUP
 BUILT IN CHARGER AND DC BATTERY BACKUP OF 5v
 DC BATTERY MONITORING SYSTEM
 INPUT TERMINAL FOR SINGLE PHASE AC SUPPLY
 OUTPUT WIRES FOR COMMUNICATION WITH
DETECTION SYSTEM AND ALARM SYSTEM

7. ALARM AND COMMUNICATION SYSTEM
 BUZZER AND BRIGHT RED LED FOR
PHYSICAL NOTIFICATION OF LPG GAS
LEAK AND DC BATTERY STATUS.
 AN HC 05 BLUETOOTH MODULE FOR
COMMUNICATION WITH NEARBY
SMARTPHONE OR SERVER.

8. • It contains Arduino board, LPG GAS Sensor
Module, 3 resistors and a buzzer.
• Arduino controls the whole process of this
system like reading LPG Gas sensor module
output, sending signal to the Red LED to glow.
• LPG gas sensor module's A0 pin is directly
connected to pin A0 of Arduino.
• Vcc and GND are connected to Vcc and GND
of Arduino.
• A buzzer is connected with Arduino pin
number 13.
Circuit description

9.  A LPG gas sensor module MQ-5 is used to detect LPG Gas.
 When Arduino gets a HIGH pulse
 An emergency light or LED light glows from LPG gas module.
 Activates buzzer which beeps again and again until the gas detector
module doesn't sense the gas in environment.
 It sends a notification “ALERT” to the app of the device with the
help of Bluetooth module HC-05.
 When the detector module gives LOW pulse to Arduino, then
green LED light starts glowing and the app shows “OK”.
Working principle

10. APPLICATION
 Home security
This system is designed mainly for home (especially kitchen area) to prevent
accidents due to gas leak.
 Automation
It can be enhanced to automate electrical cut off process to prevent short
circuit.
 Enhancement
It can be enhanced to measure specific gas levels to use in industrial
application.

11. FUTURE POSSIBILITIES
 We may also add a feedback system to check the operation of sensor and
microcontroller time to time.
 The dc backup system being idle may get damaged so to check its condition
proper dc voltage monitoring system needs to be employed.
 As the buzzer causes vibration and works at high voltage which can cause
sparking and lead to fire, thus the buzzer must be placed in proper fire proof
enclosure.

12. SYSTEM FAILURE
 GAS DETECTOR – IT REQUIRES A MINIMUM TEMPERATURE
FOR WORKING.
 CONTINIOUS USE CAN CAUSE FADING OF SENSITIVITY OF
SENSOR.
 PROBLEM IN MICROCONTROLLER WORKING AND VOLTAVE
SENSING
 AC-DC CONVERSION SYSTEM AND DC BATTERY BACKUP
 BLUETOOTH MODULE COMMUNICATION FAILURE

13. HOW TO TACKLE
 THE WHOLE SYSTEM NEEDS AN CONTIONOUS AND
PERIODIC HEALTH ANALYSIS TO BE DONE AND
REPORT SENT TO SERVER
 NEED TO SETUP AN AUTOMATIC GAS SENSOR
SENSITIVITY ANALYSIS SYSTEM
 DC BACKUP MAY GET DAMAGED DUE TO
CONTINIOUS IDLENESS THUS POWER SUPPLY MUST
BE EXCHANGED FROM TIME TO TIME.
 DC BACKUP OUTPUT VOLTAGE ANALYSIS TO BE
DONE.

14. CONCLUSION…….
The LPG is now being used in everywhere – at home, car and
even in hospital, hotel etc. There are many cases of major
accidents caused by Gas leakage.
Since there are provision of ‘Buzzer” as well as “ALERT
notification” which is visible in mobile through Bluetooth form
some distance, hence its usefulness will be tremendous.
With our project we could be able to prevent all types of
accidents due to leakage of LPG.

15. • SAURABH BASAK
• SAYAN SARKAR
• SIDDHARTHA BASU
• SPANDAN PAUL