MQUnifiedsensor

This library allows you to read the MQ sensors very easily. This library allows an Arduino/Genuino/ESP8266 board to read MQ Sensors (AIr quality meter) references: MQ2, MQ3, MQ4, MQ5, MQ6, MQ7, MQ8, MQ9, MQ131, MQ135, MQ303A, MQ309A.