REFERENCE GAS Leak/SMOKE Sensor Arduino Library

[aybyd]

Hi, just want to share one of my created library for GAS Leak and Smoke Sensor device for Arduino.
Here is my library. I created this for one of my project I designed for some Universities.

Header File: MQxSensor.h

//Created by: Aybyd Romero (c)2015
//Public License

#ifndef MQxSensor_h
#define MQxSensor_h

#if ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif

#define DEBUG_MQxSensor

// Define where debug output will be printed.
#define DEBUG_PRINTER Serial

// Setup debug printing macros.

#ifdef DEBUG_MQxSensor
#define DEBUG_PRINT(...) { DEBUG_PRINTER.print(__VA_ARGS__); }
#define DEBUG_PRINTLN(...) { DEBUG_PRINTER.println(__VA_ARGS__); }
#else
#define DEBUG_PRINT(...) {}
#define DEBUG_PRINTLN(...) {}
#endif


#define         CLEAN_AIR_FACTOR          (9.83)
#define         _LPG                         (0)
#define         _CO                          (1)
#define         _SMOKE                       (2)


class MQxSensor
{

  public:
    MQxSensor(int pin, int res);
    void begin(void);
    int MQxGetLPG();
    int MQxGetCO();
    int MQxGetSMOKE();


  private:
    int   MQx_PIN;
    int   MQx_LoadRes;
    int   MQxGetConcentration(float ratio, int id);
    float MQxSensorResistance(int adc);
    float MQxCalibrate();
    float MQRead();
    int   MQxGetPPM(float ratio, float *curve);

    //This logarithmic x,y,slope data are for MQ2 Sensor, please refer to datasheet for type of sensor you have
    float LPGCurve[3] = {2.3, 0.21, -0.47};
    float COCurve[3] = {2.3, 0.72, -0.34};
    float SmokeCurve[3] = {2.3, 0.53, -0.44};
    float Ro = 10;

};



#endif

Source File: MQxSensor.cpp

#include "MQxSensor.h"

MQxSensor::MQxSensor(int pin, int res) {
  MQx_PIN = pin;
  MQx_LoadRes = res;
}

int MQxSensor::MQxGetLPG() {
  return MQxGetConcentration(MQRead() / Ro, _LPG) ;
}

int MQxSensor::MQxGetCO() {
  return MQxGetConcentration(MQRead() / Ro, _CO) ;
}

int MQxSensor::MQxGetSMOKE() {
  return MQxGetConcentration(MQRead() / Ro, _SMOKE) ;
}

void MQxSensor::begin(void) {
  DEBUG_PRINTLN(F("Calibrating..."));
  Ro = MQxCalibrate();

  DEBUG_PRINTLN(F("Calibration done..."));
  DEBUG_PRINTLN(F("Ro:"));
  DEBUG_PRINT(Ro);
}

float MQxSensor::MQxSensorResistance(int adc)
{
  //DEBUG_PRINT(raw_adc);
  return ( ((float)MQx_LoadRes * (1023 - adc) / adc));
}

float MQxSensor::MQxCalibrate()
{
  int i;
  float val = 0;

  for (i = 0; i < 50; i++) {
    val += MQxSensorResistance(analogRead(MQx_PIN));
    delay(500);
  }
  val = val / 50;
  val = val / CLEAN_AIR_FACTOR;
  return val;
}

float MQxSensor::MQRead()
{
  int i;
  float res = 0;

  for (i = 0; i < 5; i++) {
    res += MQxSensorResistance(analogRead(MQx_PIN));
    delay(50);
  }
  res = res / 5;
  return res;
}

int MQxSensor::MQxGetConcentration(float ratio, int id)
{
  if ( id == _LPG ) {
    return MQxGetPPM(ratio, LPGCurve);
  } else if ( id == _CO ) {
    return MQxGetPPM(ratio, COCurve);
  } else if ( id == _SMOKE ) {
    return MQxGetPPM(ratio, SmokeCurve);
  }
  return 0;
}

int  MQxSensor::MQxGetPPM(float ratio, float *curve)
{
  return (pow(10, ( ((log(ratio) - curve[1]) / curve[2]) + curve[0])));
}

Sample Usage:

#include <MQxSensor.h>

MQxSensor sensor(0, 10); // xAnalog Pin#, xResistant of resistor on board x1000, in this layout we used 37 kilo ohms that set to default value of 10.

void setup() {
  Serial.begin(9600);
  sensor.begin();
}

void loop() {
  Serial.print("SMOKE: ");
  Serial.println(sensor.MQxGetSMOKE());
  Serial.print("GAS/LPG: ");
  Serial.println(sensor.MQxGetLPG());
  Serial.print("CO: ");
  Serial.println(sensor.MQxGetCO());
}

Enjoy sensing

This is the sensor I used on the sample codes:

You can also use any MQx Gas and Smoke Sensor, just change the logarithmic value according to the datasheet.

 

[Dites]

pag gumana yan... ng maayos, magandang imarket yan....

 

[wallyavila66]

salamat bro pwd pang market to