Methane Gas Sensor MQ4 (Analog/Digital)

From the shop's description

MQ-4 Sensor is highly sensitive to Methane - CH4. Using a MQ sensor and detecting the gas is quite easy. You can either use the digital pin or the analog pin to accomplish this. Simply power the module with 5V and you should notice the power LED on the module to glow and when no gas is detected the output LED will remain turned off meaning the digital output pin will be 0V. Features Power requirements: VCC - 5V±0.1. Detection Gas: Natural gas/Methane. Good sensitivity to Combustible gas in wide range. High sensitivity to CH4, Natural gas. Small sensitivity to alcohol, smoke. Fast response Stable and long life. Simple drive circuit. MQ-4 Methane Gas Sensor datasheet