GH-312 Sensor Used in Making Gas Sensor

The main goal of the project is to determine several types of gases by creating a PIC16F84A gas detector which relies on its GH-312 sensor.

The types of gases that can be determined include smoke, butane and propane, alcohol, Methane, hydrogen, liquefied gas, and others. Since the power requirement of the sensor is 9V, a 9V battery is used for the input. A 7805 regulator handles the voltage of the microcontroller and any 12V power supply will work since the sensor can handle 9V to 20V.

When tested initially on a breadboard, the display shows “No Gas” message when the circuit enters a normal state after initialization. The portable gas soldering iron with the gas coming out pointed to the sensor was used during the testing of the sensor. The flashing LED warning and sound is triggered by the microcontroller during the detection of the gas. This time, the display shows the message “Found Gas” and a small piezo produces the sound. The sensor does not sense any gas and the circuit will return to normal state when the air is clean again. It’s cheap and easily assemble.

Rest of the project