/* MQUnifiedsensor Library - reading an MQ9 Demonstrates the use a MQ9 sensor. Library originally added 01 may 2019 by Miguel A Califa, Yersson Carrillo, Ghiordy Contreras, Mario Rodriguez Added example modified 23 May 2019 by Miguel Califa This example code is in the public domain. */ //Include the library #include //Definitions #define pin A0 //Analog input 0 of your arduino #define type 9 //MQ9 //Declare Sensor MQUnifiedsensor MQ9(pin, type); void setup() { //init the sensor /***************************** MQInicializar**************************************** Input: pin, type Output: Remarks: This function create the sensor object. ************************************************************************************/ MQ9.inicializar(); } void loop() { /***************************** MQReadSensor **************************************** Input: Gas - Serial print flag Output: Value in PPM Remarks: This function use readPPM to read the value in PPM the gas in the air. ************************************************************************************/ //Read the sensor and print in serial port //Lecture will be saved in lecture variable int lecture = MQ8.readSensor("", true); // Return LPG concentration // Options, uncomment where you need //int lecture = MQ8.readSensor("LPG", true); // Return LPG concentration //int lecture = MQ8.readSensor("CH4", true); // Return CH4 concentration //int lecture = MQ8.readSensor("CO", true); // Return CO concentration delay(400); }