LPG Gas Leakage Detection System

An LPG Gas Leakage Detection System is designed to detect the presence of LPG or other combustible gases and provide an immediate warning when the gas concentration exceeds a predefined threshold. The system uses an STM32 Nucleo-L031K6 as the main controller and an MQ2 gas sensor to monitor gas levels.

Simulation image showing the working of LPG Gas Leakage Detection System

When the detected gas level reaches or exceeds the set threshold, the system activates a buzzer alarm and displays a warning on the SSD1306 OLED. The gas value and system status are also displayed through the Serial Monitor, allowing the system to be monitored and tested in real time.

The complete system was designed and tested using the Wokwi simulation environment.

Components Required

S. No.	Component	Quantity	Purpose
1	STM32 Nucleo-L031K6	1	Main controller for processing gas sensor data
2	MQ2 Gas Sensor	1	Detects the presence and level of combustible gas
3	SSD1306 OLED Display	1	Displays the gas value and system status
4	Buzzer	1	Provides an audible warning when gas leakage is detected
5	Jumper Wires	As required	Connects the components to the STM32 board

System Overview and Working Principle

The LPG Gas Leakage Detection System consists of an STM32 Nucleo-L031K6, an MQ2 gas sensor, an SSD1306 OLED display, and a buzzer. The STM32 acts as the main controller and processes the gas-level data received from the MQ2 sensor.

Working Principle

1. The MQ2 gas sensor measures the surrounding gas level and provides an analog output to the STM32.

2. The STM32 continuously reads the gas sensor value through its analog input.

3. A predefined threshold of 700 is used to determine the gas condition.

4. If the gas value is 700 or higher, the system identifies a gas leakage and activates the buzzer.

5. If the gas value is below 700, the system considers the condition SAFE and keeps the buzzer OFF.

6. The gas value and current status are displayed on the SSD1306 OLED and Serial Monitor.

Circuit Connections

Component	Pin	STM32 Nucleo Pin	Purpose
MQ2 Gas Sensor	AOUT	A0	Analog gas-level input
MQ2 Gas Sensor	VCC	3.3V	Power supply
MQ2 Gas Sensor	GND	GND	Ground
SSD1306 OLED	SDA	D4	I²C data
SSD1306 OLED	SCL	D5	I²C clock
SSD1306 OLED	VCC	3.3V	Power supply
SSD1306 OLED	GND	GND	Ground
Buzzer	+	D6	Alarm output
Buzzer	−	GND	Ground

Programming and Implementation

The system is programmed using the Arduino framework for the STM32 Nucleo-L031K6. The MQ2 sensor is read through the STM32's analog input, while the OLED and buzzer provide the output indications.

5.1 Pin Configuration

The following pins are defined in the program:

• A0 → MQ2 analog gas input

• D6 → Buzzer output

• D4 and D5 → OLED I²C communication

• 0x3C → OLED I²C address

• 700 → Gas detection threshold

5.2 Gas Detection

The MQ2 analog value is continuously read and compared with the predefined threshold.

This demonstrates:

• Reading the MQ2 analog value

• Comparing it with the 700 threshold

• Turning the buzzer ON when a leak is detected

• Turning the buzzer OFF under safe conditions

5.3 OLED Display

The OLED displays the current gas value and status, while the buzzer provides an audible warning during a detected gas-leak condition.

5.4 Source Code

LPG_Gas_Leakage_Detection_Source_Code.txt

Download TXT • 6KB

Simulation and Output

The complete LPG Gas Leakage Detection System was simulated in Wokwi to verify the operation of the MQ2 gas sensor, OLED display, and buzzer.

Wokwi simulation output of the LPG Gas Leakage Detection System under a gas-leak condition.

Future Scope

The LPG Gas Leakage Detection System can be further enhanced by:

• IoT connectivity for remote gas-level monitoring and alerts.

• Mobile application integration to notify users about gas leakage conditions.

• Automatic gas shut-off using a solenoid valve to improve safety.

• Additional gas sensors for detecting different types of combustible gases.

• SMS or cloud-based alerts for immediate notification during a leakage.

• Battery backup to maintain operation during power failures

Conclusion

The LPG Gas Leakage Detection System was successfully designed and simulated using the STM32 Nucleo-L031K6, MQ2 gas sensor, SSD1306 OLED display, and buzzer. The system continuously monitors the gas level and compares it with a predefined threshold to identify leakage conditions.

When the gas level exceeds the threshold, the system displays a GAS LEAK DETECTED warning and activates the buzzer. Under safe gas levels, the system displays SAFE and keeps the buzzer OFF. The successful Wokwi simulation confirms that the system performs the intended gas monitoring and alert functions in real time.