Interfacing Gas Sensor (MQ2) With AVR
After basic peripheral interfaces with AVR, it's time to interface some sensors with it. In this tutorial we will interface Gas sensor MQ2 with Atmega 32 breakout. We will require a Smoke Sensor (MQ2) Board .
Basics
The gas sensor MQ2 suitable for detecting of LPG, i-butane, propane, methane, alcohol, Hydrogen, smoke etc. Since It is highly sensitive and gives fast response, we can take measurements as soon as possible. This sensor can be used for gas leakage detection.
At normal condition, sensor resistor will be high so voltage drop across the load will be low and it will be a constant.If sensor senses flammable gases, resistance of sensor will drop. That means more current will flow from load resistor.So the voltage across it increases.
This Smoke Sensor (MQ2) Board has analog as well as digital output. For this tutorial we will use analog output. Analog output pin needs to be connect ADC channel 0 of atmega 32 breakout as shown in hook up.