DFRobot Gravity Analog Gas Sensor MQ2 for Arduino - Analog Output

The DFRobot Gravity MQ2 module requires a stable 5V DC power supply. Applying voltages outside this range can damage the onboard heater circuit and signal conditioning components. Always connect VCC to a regulated 5V source from your Arduino, Raspberry Pi, or a dedicated power supply.

Connect the module's VCC pin to 5V, GND to ground, and the Signal (AO) pin to an analog input pin on your microcontroller (e.g., Arduino A0). The sensor outputs an analog voltage that increases with gas concentration. Use the `analogRead()` function in Arduino to get a value between 0 and 1023, which you can then map to a concentration level through calibration.

Yes, the module includes a blue potentiometer for sensitivity adjustment. Turning the potentiometer changes the baseline output voltage, allowing you to set a detection threshold for your specific application and environment. A higher resistance setting typically increases sensitivity, but requires recalibration.

The MQ2 is sensitive to a broad range of combustible gases including Liquefied Petroleum Gas (LPG), i-butane, propane, methane (natural gas), alcohol, and hydrogen. It also responds to smoke. It is not selective to a single gas type, so it is best used as a general combustible gas or leak detector.

While it operates at 5V, the MQ2 sensor contains a heater that draws significant current (approx. 150-200mA during warm-up). This makes it less ideal for direct battery-powered projects without a high-capacity power source. For low-power applications, consider sensors with lower heater current or pulsed heating modes.