//https://navody.arduino-shop.cz/navody-k-produktum/komunikace-po-i2c-mezi-arduino-deskami.html
#include <Wire.h>
#include <MQUnifiedsensor.h>

//Definitions
#define placa "Arduino NANO"
#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
int CO = 0;
int Alcohol = 0;
int CO2 = 0;
int Tolueno = 0;
int NH4 = 0;
int Acetona = 0;

//Declare Sensor
MQUnifiedsensor MQ135(placa, Voltage_Resolution, ADC_Bit_Resolution, pin, type);


void setup() {
  Serial.begin(115200);
  Wire.begin(0x01);
  //Set math model to calculate the PPM concentration and the value of constants
  MQ135.setRegressionMethod(1); //_PPM =  a*ratio^b
  //Remarks: Configure the pin of arduino as input.
  /************************************************************************************/ 
  MQ135.init();
  /* 
    //If the RL value is different from 10K please assign your RL value with the following method:
    MQ135.setRL(10);
  */
  /*****************************  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
  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);
    
  }
  MQ135.setR0(calcR0/10);
  
}

void loop() {
  merime();
  Wire.beginTransmission(0x02);
  Wire.write(CO);
  Wire.write(Alcohol);
  Wire.write(CO2);
  Wire.write(Tolueno);
  Wire.write(NH4);
  Wire.write(Acetona);
delay(1000*60*5);
}

//########################################################
void merime(){
  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

}