/* MQUnifiedsensor Library - reading an MQ4 Demonstrates the use a MQ4 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 4 //MQ4 //#define calibration_button 13 //Pin to calibrate your sensor //Declare Sensor MQUnifiedsensor MQ4(pin, type); //Variables float CH4, LPG, CO, Alcohol, smoke; void setup() { Serial.begin(9600); //Init serial port //init the sensor /***************************** MQInicializar**************************************** Input: pin, type Output: Remarks: This function create the sensor object. ************************************************************************************/ MQ4.inicializar(); //pinMode(calibration_button, INPUT); } void loop() { MQ4.update(); // Update data, the arduino will be read the voltaje in the analog pin /* //Si el valor de RL es diferente a 10K por favor asigna tu valor de RL con el siguiente metodo: MQ4.setRL(10); */ /* //Rutina de calibracion - Uncomment if you need (setup too and header) if(calibration_button) { float R0 = MQ4.calibrate(); MQ4.setR0(R0); } */ /***************************** 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 //float lecture = MQ4.readSensor("", true); // Return CH4 concentration // Options, uncomment where you need CH4 = MQ4.readSensor("CH4"); // Return CH4 concentration LPG = MQ4.readSensor("LPG"); // Return LPG concentration CO = MQ4.readSensor("CO"); // Return CO concentration Alcohol = MQ4.readSensor("Alcohol"); // Return Alcohol concentration smoke = MQ4.readSensor("smoke"); // Return smoke concentration Serial.println("***************************"); Serial.println("Lectures for MQ-4"); Serial.print("Volt: ");Serial.print(MQ4.getVoltage(false));Serial.println(" V"); Serial.print("R0: ");Serial.print(MQ4.getR0());Serial.println(" Ohm"); Serial.print("CH4: ");Serial.print(CH4,2);Serial.println(" ppm"); Serial.print("LPG: ");Serial.print(LPG,2);Serial.println(" ppm"); Serial.print("CO: ");Serial.print(CO,2);Serial.println(" ppm"); Serial.print("Alcohol: ");Serial.print(Alcohol,2);Serial.println(" ppm"); Serial.print("smoke: ");Serial.print(smoke,2);Serial.println(" ppm"); Serial.println("***************************"); }