Leaking LPG may be a disaster even though it is an essential need of every household. LPG leak detection is done by various products that detect the leakage and prevent any mishappening. An LPG gas detection alarm is developed using an Arduino. The circuit buzzes if there is a leak in gas and that triggers a signal from the system. This system is extremely easy to construct, and anyone with programming and electronics skills can do it. The LPG gas was detected using an LPG sensor module. Whenever LPG leaks, it sends a HIGH pulse to the DO pin, which Arduino stays in continuous contact with. A 16x2 LCD displays the message "LPG Gas Leakage Alert" when Arduino detects a HIGH pulse from LPG Gas module. The gas detector module beeps repeatedly until no gas is detected in the environment, leading to the buzzer being activated. The LCD displays a "No LPG Gas Leakage" message when the LPG gas detector outputs a LOW signal to the Arduino. Components Used Arduino Pro Mini LPG Gas sensor Module Buzzer, BC 547 Transistor

16x2 LCD, 1K resistor, Bread board 9-volt battery, Connecting wires Circuit and Description As you can see from the schematic diagram above, it has an Arduino board, an LPG GAS Sensor Module, a buzzer, and a 16x2 LCD module. This system is controlled by Arduino, which reads the gas sensor's output, sends messages to the LCD and activates the buzzer. This sensor module has an inbuilt potentiometer that we can use to set its sensitivity. DO, pin 18 (A4), of the LPG sensor module is connected directly to Arduino's Vcc and GND pins. A MQ3 sensor detects LPG gas in the LPG gas sensor module. In order for the heater to heat up, the MQ3 sensor will require some electrical power, and it may take up to fifteen minutes for it to get ready for detecting LPG gas.

An analog to digital converter circuit converts the output of MQ3 to a digital signal. Four-bit mode is used to connect a 16x2 LCD to Arduino. Arduino pin 2 and GND are directly connected to pins RS, RW and En while pins 4, 5, 6 and 7 of the Arduino are connected to the data pins. Through a binary NPN BC547 transistor coupled to pin 13 of the Arduino, a buzzer is connected. LPG Gas Sensor Module In this module, we find a MQ3 sensor, which actually detects the presence of LPG, and a comparator (LM393), which compares the sensor's output voltage with the reference voltage. When LPG gas is present, it will emit a HIGH output signal. Potentiometers are also used to control the sensitivity of gas sensors. In addition, it can be made with LM358 or LM393 and MQ3, which can be accessed by microcontrollers and Arduinos quite easily. There is also a “LPG Gas Sensor Module” readily available on the market.