From d7b1ed1314bf17b704d4372c966e227a89a0581c Mon Sep 17 00:00:00 2001 From: miguel5612 Date: Sun, 29 Mar 2020 20:48:45 -0500 Subject: [PATCH] Added MQ-135 all gases --- examples/MQ-135-ALL/MQ-135-ALL.ino | 121 +++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 examples/MQ-135-ALL/MQ-135-ALL.ino diff --git a/examples/MQ-135-ALL/MQ-135-ALL.ino b/examples/MQ-135-ALL/MQ-135-ALL.ino new file mode 100644 index 0000000..4fe96f8 --- /dev/null +++ b/examples/MQ-135-ALL/MQ-135-ALL.ino @@ -0,0 +1,121 @@ +/* + MQUnifiedsensor Library - reading an MQ135 + + Demonstrates the use a MQ135 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 + + Updated library usage + modified 26 March 2020 + by Miguel Califa + + This example code is in the public domain. + +*/ + +//Include the library +#include + +//Definitions +#define placa "Arduino UNO" +#define Voltage_Resolution 5 +#define pin A0 //Analog input 0 of your arduino +#define type "MQ-135" //MQ135 +#define ADC_Bit_Resolution 10 // For arduino UNO/MEGA/NANO +#define RatioMQ135CleanAir 3.6//RS / R0 = 3.6 ppm +//#define calibration_button 13 //Pin to calibrate your sensor + +//Declare Sensor +MQUnifiedsensor MQ135(placa, Voltage_Resolution, ADC_Bit_Resolution, pin, type); + +void setup() { + //Init the serial port communication - to debug the library + Serial.begin(9600); //Init serial port + + //Set math model to calculate the PPM concentration and the value of constants + MQ135.setRegressionMethod(1); //_PPM = a*ratio^b + + + /***************************** MQ CAlibration ********************************************/ + // Explanation: + // In this routine the sensor will measure the resistance of the sensor supposing before was pre-heated + // and now is on clean air (Calibration conditions), and it will setup R0 value. + // We recomend execute this routine only on setup or on the laboratory and save on the eeprom of your arduino + // This routine not need to execute to every restart, you can load your R0 if you know the value + // Acknowledgements: https://jayconsystems.com/blog/understanding-a-gas-sensor + Serial.print("Calibrating please wait."); + float calcR0 = 0; + for(int i = 1; i<=10; i ++) + { + MQ135.update(); // Update data, the arduino will be read the voltage on the analog pin + calcR0 += MQ135.calibrate(RatioMQ135CleanAir); + Serial.print("."); + } + MQ135.setR0(calcR0/10); + Serial.println(" done!."); + + if(isinf(calcR0)) {Serial.println("Warning: Conection issue founded, R0 is infite (Open circuit detected) please check your wiring and supply"); while(1);} + if(calcR0 == 0){Serial.println("Warning: Conection issue founded, R0 is zero (Analog pin with short circuit to ground) please check your wiring and supply"); while(1);} + /***************************** MQ CAlibration ********************************************/ + + /* + //If the RL value is different from 10K please assign your RL value with the following method: + MQ135.setRL(10); + */ + + MQ135.init(); + /***************************** MQ Init ********************************************/ + //Input: setup flag, if this function are on setup will print the headers (Optional - Default value: False) + //Output: print on serial port the information about sensor and sensor readings + //Remarks: Configure the pin of arduino as input. + /************************************************************************************/ + + Serial.println("** Lectures from MQ-135 ****"); + Serial.println("| CO | Alcohol | CO2 | Tolueno | NH4 | Acteona |"); +} + +void loop() { + MQ135.update(); // Update data, the arduino will be read the voltage on the analog pin + + MQ135.setA(605.18); MQ135.setB(-3.937); // Configurate the ecuation values to get CO concentration + float CO = MQ135.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup + + MQ135.setA(77.255); MQ135.setB(-3.18); // Configurate the ecuation values to get Alcohol concentration + float Alcohol = MQ135.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup + + MQ135.setA(110.47); MQ135.setB(-2.862); // Configurate the ecuation values to get CO2 concentration + float CO2 = MQ135.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup + + MQ135.setA(44.947); MQ135.setB(-3.445); // Configurate the ecuation values to get Tolueno concentration + float Tolueno = MQ135.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup + + MQ135.setA(102.2 ); MQ135.setB(-2.473); // Configurate the ecuation values to get NH4 concentration + float NH4 = MQ135.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup + + MQ135.setA(34.668); MQ135.setB(-3.369); // Configurate the ecuation values to get Acetona concentration + float Acetona = MQ135.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup + + Serial.print("| "); Serial.print(CO); + Serial.print(" | "); Serial.print(Alcohol); + Serial.print(" | "); Serial.print(CO2); + Serial.print(" | "); Serial.print(Tolueno); + Serial.print(" | "); Serial.print(NH4); + Serial.print(" | "); Serial.print(Acetona); + Serial.println(" |"); + /* + Exponential regression: + GAS | a | b + CO | 605.18 | -3.937 + Alcohol | 77.255 | -3.18 + CO2 | 110.47 | -2.862 + Tolueno | 44.947 | -3.445 + NH4 | 102.2 | -2.473 + Acetona | 34.668 | -3.369 + */ + + delay(500); //Sampling frequency +} \ No newline at end of file