MQSensorsLib

We present a unified library for MQ sensors, this library allows to read MQ signals easily from Arduino, Genuino, ESP8266, ESP-32 boards whose references are MQ2, MQ3, MQ4, MQ5, MQ6, MQ7, MQ8, MQ9, MQ131, MQ135, MQ303A, MQ309A.

Getting Started
Wiring
User Manual
Sensor manufacturers
Contributing
Authors
Be a sponsor 💖

Getting Started

//Include the library
#include <MQUnifiedsensor.h>
/************************Hardware Related Macros************************************/
#define         Board                   ("Arduino UNO")
#define         Pin                     (A4)  //Analog input 4 of your arduino
/***********************Software Related Macros************************************/
#define         Type                    ("MQ-4") //MQ4
#define         Voltage_Resolution      (5)
#define         ADC_Bit_Resolution      (10) // For arduino UNO/MEGA/NANO
#define         RatioMQ4CleanAir        (4.4) //RS / R0 = 60 ppm 
/*****************************Globals***********************************************/
//Declare Sensor
MQUnifiedsensor MQ4(Board, Voltage_Resolution, ADC_Bit_Resolution, Pin, Type);
// Setup
MQ4.setRegressionMethod("Exponential"); //_PPM =  a*ratio^b
MQ4.setA(1012.7); MQ4.setB(-2.786); // Configure the equation to to calculate CH4 concentration
MQ4.setR0(3.86018237); // Value getted on calibration
// Loop
MQ4.init();
MQ4.update();
float ppmCH4 = MQ4.readSensor();

Wiring

Sensor

Important points:

Points you should identify

VCC -> 5V Power supply (+) wire
GND -> GND Ground (-) wire
AO -> Analog Output of the sensor

Data of board that you should have

RL Value in KOhms

Graph

RS/R0 value (From datasheet of your sensor)

RS/R0 (Clean air - English) -> (Aire puro - Spanish)
Note: RS/R0 is equal to Ratio variable on the program

Arduino

MQ-7 / MQ-309A

** Note ** issue: MQ-7 and MQ-309 needs two different voltages for heater, they can be supplied by PWM and DC Signal controlled by your controller, another option is to use two different power sources, you should use the best option for you, next i will show the PWM option and on the examples this will be the way .

ESP8266-ESP32

ESP32 WROOM 32D

The ESP32 WROOM 32D does not need an external power supply. A0 goes to PIN36, Vcc to 3v3 and GND to any GND port on the board. Check the ESP2/ESP32_WROOM_32 folder to fixing the measuring issue when connecting to wifi.

Manuals

User Manual (v1.0) 12.2019

Manual

User Manual (v2.0) 04.2020

Manual

Serial debug (optional)

If your sensor is an MQ2 (Same for others sensors):

To enable on setup wrote

MQ2.serialDebug(true);

And on Loop Wrote

MQ2.serialDebug();

Result:

Note:

Yellow -> Calibration status.
Green -> Hardware and software characteristics.
Red -> Headers of the library calculations.
Only valid for 1 gas sensor readings.

Usage

Quick troubleshooting, since it shows everything the library does and the results of the calculations in each function.

Prerequisites

You'll need Arduino desktop app 1.8.9 or later.

Sensor manufacturers:

Sensor	Manufacture	URL Datasheet
MQ-2	Pololulu	datasheet
MQ-3	Sparkfun	datasheet
MQ-4	Sparkfun	datasheet
MQ-5	parallax	datasheet
MQ-6	Sparkfun	datasheet
MQ-7	Sparkfun	datasheet
MQ-8	Sparkfun	datasheet
MQ-9	Haoyuelectronics	datasheet
MQ-131	Sensorsportal	datasheet
MQ-135	HANWEI Electronics	datasheet
MQ-136	HANWEI Electronics	datasheet
MQ-303A	HANWEI Electronics	datasheet
MQ-309A	HANWEI Electronics	datasheet

Info of datasheets

Review WPDigitalizer folder website

Installing

Clone this repository into your desktop machine

git clone https://github.com/miguel5612/MQSensorsLib

Running the tests

Use calibration systems if you have several sensors that read the same gas.

Break down into end to end tests

These tests can re-adjust values defined previously and you can contribute to improve conditions or features obtained from particular scenes.

Examples/MQ-3

And coding style tests

These tests may generate statistics validation using descriptive tools for quantitative variables.

Examples/MQ-board.ino

Built With

Data sheets - Curves and behavior for each sensor, using logarithmic graphs.
Main purpose - Every sensor has high sensibility for a specific gas or material.

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Reviewers

PhD. Jacipt A Ramón V. - GitHub - CV

Authors

Miguel A. Califa U. - GitHub - CV
Ghiordy F. Contreras C. - GitHub - CV
Yersson R. Carrillo A. - GitHub - CV

Collaborators

Andres A. Martinez. - Github - CV
Juan A. Rodríguez. - Github - CV
Mario A. Rodríguez O. - GitHub - CV

See also the list of contributors who participated in this project.

License

This project is licensed under the MIT License - see the LICENSE.md file for details

Cite as

Plain text: Califa Urquiza, Miguel Angel, Contreras Contreras, Ghiordy, & Carrillo Amado, Yerson Ramiro. (2019, September 3). miguel5612/MQSensorsLib: Arduino Preview V1.03 (Version 1.0.3). Zenodo. http://doi.org/10.5281/zenodo.3384301
CSL: { "publisher": "Zenodo", "DOI": "10.5281/zenodo.3384301", "title": "miguel5612/MQSensorsLib: Arduino Preview V1.03", "issued": { "date-parts": [ [ 2019, 9, 3 ] ] }, "abstract": "
Publishing on Zenodo platform as software in order to extend its applications for other works allowing to recognize MQSensorLib's Authors this work into scientific community using Digital Object Identifier System (DOI).
", "author": [ { "family": "Califa Urquiza, Miguel Angel" }, { "family": "Contreras Contreras, Ghiordy" }, { "family": "Carrillo Amado, Yerson Ramiro" } ], "version": "1.0.3", "type": "article", "id": "3384301" }
BibTeX: @misc{califa_urquiza_miguel_angel_2019_3384301, author = {Califa Urquiza, Miguel Angel and Contreras Contreras, Ghiordy and Carrillo Amado, Yerson Ramiro}, title = {miguel5612/MQSensorsLib: Arduino Preview V1.03}, month = sep, year = 2019, doi = {10.5281/zenodo.3384301}, url = {https://doi.org/10.5281/zenodo.3384301} }

Sponsor

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SMH17/MQSensorsLib