Tinycontrol MQ-4 Methane Sensor

Using the Tinycontrol MQ-4 sensor and detecting the gas is quite simple. You can use either the digital pin or the analog pin for this purpose. Simply power the module with 5V and you should notice that the power LED on the module will be on and when no gas is detected, the output LED will remain off, meaning that there will be 0V on the digital output.

You can also use analog pin for gas detection. Read the analog values (0-5V) using the microcontroller, the value will be directly proportional to the concentration of gas that the sensor is detecting. You can experiment with these values and see how the sensor reacts to different gas concentrations and design your program accordingly.