#include <Wire.h>
#include <LiquidCrystal_I2C.h>

#include <OneWire.h>
#include <DallasTemperature.h>

#define SDA_PIN 21
#define SCL_PIN 20

LiquidCrystal_I2C lcd(0x27, 16, 2);

//----------------------
// Pin Definitions
//----------------------

#define TEMP_PIN 4

#define PH_PIN 34
#define TURBIDITY_PIN 35
#define TDS_PIN 36

#define GREEN_LED 18
#define RED_LED 19

//----------------------
// DS18B20
//----------------------

OneWire oneWire(TEMP_PIN);
DallasTemperature sensors(&oneWire);

//----------------------
// Variables
//----------------------

float temperature;

float phValue;

float turbidity;

float tds;

float WQI;

String status;
void setup()
{

Serial.begin(115200);

Wire.begin(SDA_PIN,SCL_PIN);

lcd.init();

lcd.backlight();

sensors.begin();

pinMode(GREEN_LED,OUTPUT);

pinMode(RED_LED,OUTPUT);

digitalWrite(GREEN_LED,LOW);

digitalWrite(RED_LED,LOW);

lcd.clear();

lcd.setCursor(0,0);
lcd.print(" WATER BODY");

lcd.setCursor(0,1);
lcd.print(" GUARDIAN ");

delay(2000);

lcd.clear();

lcd.setCursor(0,0);
lcd.print("Initializing");

for(int i=0;i<16;i++)
{
lcd.setCursor(i,1);
lcd.print((char)255);
delay(120);
}

lcd.clear();

}
float readTemperature()
{

sensors.requestTemperatures();

float t=sensors.getTempCByIndex(0);

if(t==-127)
{

t=25;

}

return t;

}
float readPH()
{

int value=analogRead(PH_PIN);

float voltage=value*3.3/4095.0;

float ph=3+(voltage/3.3)*11;

return ph;

}
float readTurbidity()
{

int value=analogRead(TURBIDITY_PIN);

float ntu=map(value,0,4095,0,1000);

return ntu;

}
float readTDS()
{

int value=analogRead(TDS_PIN);

float ppm=map(value,0,4095,0,1200);

return ppm;

}
float calculateWQI(float temp,float ph,float turb,float tds)
{

float tempScore;
float phScore;
float turbScore;
float tdsScore;

// Temperature Score

if(temp>=20 && temp<=35)
tempScore=100;

else if(temp>=15 && temp<=40)
tempScore=80;

else
tempScore=50;

// pH Score

if(ph>=6.5 && ph<=8.5)
phScore=100;

else if(ph>=5.5 && ph<=9.5)
phScore=70;

else
phScore=40;

// Turbidity Score

if(turb<=300)
turbScore=100;

else if(turb<=600)
turbScore=70;

else
turbScore=40;

// TDS Score

if(tds<=500)
tdsScore=100;

else if(tds<=900)
tdsScore=70;

else
tdsScore=40;

float wqi=(tempScore+phScore+turbScore+tdsScore)/4.0;

return wqi;

}
String getStatus(float wqi)
{

if(wqi>=90)
return "EXCELLENT";

else if(wqi>=75)
return "GOOD";

else if(wqi>=60)
return "AVERAGE";

else if(wqi>=40)
return "POOR";

else
return "POLLUTED";

}
void controlLED(String state)
{

if(state=="EXCELLENT" || state=="GOOD")
{

digitalWrite(GREEN_LED,HIGH);

digitalWrite(RED_LED,LOW);

}

else
{

digitalWrite(GREEN_LED,LOW);

digitalWrite(RED_LED,HIGH);

}

}
void screen1()
{

lcd.clear();

lcd.setCursor(0,0);
lcd.print("Temp:");
lcd.print(temperature,1);
lcd.print("C");

lcd.setCursor(0,1);
lcd.print("pH:");
lcd.print(phValue,1);

delay(2000);

}
void screen2()
{

lcd.clear();

lcd.setCursor(0,0);
lcd.print("Turb:");
lcd.print((int)turbidity);

lcd.setCursor(0,1);
lcd.print("TDS:");
lcd.print((int)tds);

delay(2000);

}
void screen3()
{

lcd.clear();

lcd.setCursor(0,0);
lcd.print("WQI:");
lcd.print(WQI,0);

lcd.setCursor(0,1);
lcd.print(status);

delay(2500);

}
void serialData()
{

Serial.println("--------------------------------");

Serial.print("Temperature : ");
Serial.print(temperature);
Serial.println(" C");

Serial.print("pH : ");
Serial.println(phValue);

Serial.print("Turbidity : ");
Serial.print(turbidity);
Serial.println(" NTU");

Serial.print("TDS : ");
Serial.print(tds);
Serial.println(" ppm");

Serial.print("WQI : ");
Serial.println(WQI);

Serial.print("Status : ");
Serial.println(status);

Serial.println("--------------------------------");

}
void loop()
{

  // Read Sensors
  temperature = readTemperature();
  phValue = readPH();
  turbidity = readTurbidity();
  tds = readTDS();

  // Calculate WQI
  WQI = calculateWQI(temperature, phValue, turbidity, tds);

  // Get Water Status
  status = getStatus(WQI);

  // LED Control
  controlLED(status);

  // Serial Monitor
  serialData();

  // LCD Screen 1
  screen1();

  // LCD Screen 2
  screen2();

  // LCD Screen 3
  screen3();

}