/*
Voltaat learn (http://learn.voltaat.com)
Link for full tutorial:

Tutorial: Measure the LPG gas concentration using the Arduino!
Adafruit_GFX library
Adafruit_ILI9341 library
MQ2 library
wire library

The purpose of this sketch is to display the concentration of LPG, smoke, and CO gas
in ppm obtained from the MQ-2 gas sensor on the TFT Display and to sound an alarm if
the concentration exceeds a certain value using a buzzer.

Connections from the Arduino to the breadboard:

• Arduino GND pin → Breadboard ground line

• Arduino 5V pin → Breadboard 5V line


Connections from the MQ-2 gas sensor:

• MQ-2  gas sensor VCC pin → Breadboard 5V line

• MQ-2  gas sensor GND pin → Breadboard ground line

• MQ-2 gas sensor A0 pin → Arduino pin A0


Connections from the passive buzzer:

•passive buzzer GND pin → Breadboard ground line

•passive buzzer VCC pin (+ pin) → Arduino pin 3


Connections from the TFT Display to the breadboard:

• TFT Display VCC pin → Breadboard 5V line

• TFT Display GND pin → Breadboard ground line

• TFT Display LED pin → Breadboard 5V line


Connections from the TFT Display to arduino :

• TFT Display CS pin → Arduino pin 10

• TFT Display RST pin → Arduino pin 8

• TFT Display DC pin → Arduino pin 9

• TFT Display MOSI pin → Arduino pin 11

• TFT Display SCK pin → Arduino pin 13

• TFT Display MISO pin → Arduino pin 12


*/

#include "Adafruit_GFX.h"    
#include "Adafruit_ILI9341.h"
#include "Wire.h"
#include  "SPI.h"
#include "MQ2.h"

//Define TFT Display pin numbers
#define TFT_DC 9              
#define TFT_CS 10            
#define TFT_RST 8            
#define TFT_MISO 12          
#define TFT_MOSI 11          
#define TFT_CLK 13          

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_MOSI, TFT_CLK, TFT_RST, TFT_MISO);

#define Analog_Input    A0  //analog feed from MQ-2
#define passive_buzzer    3  //define passive buzzer pin
char LPGppmChar[10];  
char SMOKEppmChar[10];
char COppmChar[10];
MQ2 mq2(Analog_Input);
void setup(){
Serial.begin(9600);
mq2.begin();
tft.begin();                      
tft.setRotation(0);            
tft.fillScreen(ILI9341_BLACK);

pinMode(passive_buzzer,OUTPUT); //define passive buzzer pin as an output pin

Wire.begin();
printText("LPG Level", ILI9341_GREEN,20,20,3);
printText("SMOKE Level", ILI9341_GREEN,20,130,3);
printText("CO Level", ILI9341_GREEN,20,230,3);
}

void loop()
{


float* values= mq2.read(true); //set it false if you don't want to print the values in the Serial
 //lpg = values[0];
float LPGPPM = mq2.readLPG();
 //co = values[1];
float COPPM = mq2.readCO();
 //smoke = values[2];
float SMOKEPPM = mq2.readSmoke();

int grafX = 0; //int for x value of graph


String LPGppmString = String(LPGPPM,1); //Convert float to string

LPGppmString.toCharArray(LPGppmChar,10);

tft.fillRect(30,70,120,40,ILI9341_BLACK); //Draw a Rectangle

printText(LPGppmChar, ILI9341_WHITE,35,70,4); //printing the lpg gas concentration on the TFT Display

printText("ppm", ILI9341_WHITE,160,70,4);


grafX = map(LPGPPM,0,1000,0,127);           //map value to screen width

tft.fillRect(0, 112, grafX, 10, ILI9341_WHITE);  //print graph 400min 1000max


String SMOKEppmString = String((SMOKEPPM*100)/1000000,1); //Convert float to string

SMOKEppmString.toCharArray(SMOKEppmChar,10);

tft.fillRect(30,170,120,40,ILI9341_BLACK); //Draw a Rectangle

printText(SMOKEppmChar, ILI9341_WHITE,35,170,4); //printing the smoke concentration on the TFT Display

printText(" %", ILI9341_WHITE,160,170,4);



grafX = map((SMOKEPPM*100)/1000000,0,1000,0,127);      //map value to screen width

tft.fillRect(0, 212, grafX, 10, ILI9341_WHITE);  //print graph 400min 1000max


String COppmString = String(COPPM,1); //Convert float to string

COppmString.toCharArray(COppmChar,10);

tft.fillRect(30,270,120,40,ILI9341_BLACK); //Draw a Rectangle

printText(COppmChar, ILI9341_WHITE,35,270,4); //printing the co gas concentration on the TFT Display

printText("ppm", ILI9341_WHITE,160,270,4);

grafX = map(COPPM,0,1000,0,127);           //map value to screen width

tft.fillRect(0, 312, grafX, 10, ILI9341_WHITE);  //print graph 400min 1000max

if(LPGPPM>400){                             //if lpg ppm >400
   digitalWrite(passive_buzzer,HIGH);                   //turn on buzzer
}
else{                                       //if not
   digitalWrite(passive_buzzer,LOW);                    //turn off buzzer
}



}

//The function of writing words on the TFT Display
void printText(char *text, uint16_t color, int x, int y,int textSize)
{
 tft.setCursor(x, y);
 tft.setTextColor(color);
 tft.setTextSize(textSize);
 tft.setTextWrap(true);
 tft.print(text);
}

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