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

//dht parameters
#define DHTPIN 3
#define DHTTYPE DHT22
float hum,temp;
float hum_value=75.00;
float hum_value_lastdays=80.00;
bool temp_flag= false;
bool hum_flag= false;

//actuators parameter
#define heater 10
#define fan 9
#define alarm 8

//timer parameter
unsigned long long time1;
//unsigned long time2=0;
const long long period= 30000;

LiquidCrystal_I2C lcd(0x27, 16,2);
DHT dht(DHTPIN, DHTTYPE);

void setup() {
  dht.begin();
  
  pinMode(fan, OUTPUT); //fan operation to maintain humidity
  pinMode(alarm, OUTPUT); //buzzer for humidity indication
  pinMode(heater, OUTPUT); //connect with relay for heating bulb/element
   
  //all the actuators are brought down for precaution
  digitalWrite(fan, LOW);
  digitalWrite(alarm, LOW);
  digitalWrite(heater,LOW);
  Serial.begin(9600);
  
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("ISA Technologies");
  delay(1000);
  lcd.clear();
  lcd.print("Setting up......");
  sensing();
  initiate();
  delay(1000);
  lcd.clear();

  lcd.setCursor(0,0);
  lcd.print("Temp :");
  lcd.setCursor(12,0);
  lcd.print("\337c"); // \337 is used to print degree symbol in LCD

  lcd.setCursor(0,1);
  lcd.print ("Humid:");
  lcd.setCursor(12,1);
  lcd.print("%");

 
}

void loop() {
  time1= millis();
  if (time1>=period){
    hum_value=hum_value_lastdays;
  }

  Serial.print(F("Temp: "));
  Serial.print(temp);
  Serial.print(F("°C "));
  Serial.println();

  Serial.print(F("Humidity: "));
  Serial.print(hum);
  Serial.print(F("%"));
  Serial.println();

  lcd.clear();
  sensing();

  lcd.setCursor(0,0);
  lcd.print("Temp :");
  lcd.setCursor(12,0);
  lcd.print("\337c"); // \337 is used to print degree symbol in LCD

  lcd.setCursor(0,1);
  lcd.print ("Humid:");
  lcd.setCursor(12,1);
  lcd.print("%");

  lcd.setCursor(6,0);
  lcd.print(temp);
  
  lcd.setCursor(6,1);
  lcd.print(hum);

  temp_control();
  humid_control();
  alarm_system();

}
void sensing(){
  hum = dht.readHumidity(); //read relative humidity in percentage
  temp = dht.readTemperature();// read temperature in deg C
  if (isnan(hum) || isnan(temp)) {
    Serial.println(F("Check the DHT Sensor!!!"));
    lcd.setCursor(0,0);
    lcd.print("Check the DHT sensor!!!");
    delay(500);
    lcd.clear();
    return;
   }
   //delay(1000);
}

void initiate(){
  if(temp>=36.00){
   digitalWrite(heater,HIGH);
   Serial.println("Heater is ON for initial temp");
   temp_flag= true;
  }
  if(hum>=65.00){
    digitalWrite(fan,LOW);
    Serial.println("Fan is OFF for initial hum");
    hum_flag= true;
  }
}

void temp_control(){
  //sensing();
  if ((temp <= 36.0) && (temp_flag == false)){
    digitalWrite(heater, HIGH);
    Serial.println("Heater is ON");
    temp_flag= true;
  }
  if((temp>=36.7) && (temp_flag == true)){
    digitalWrite(heater,LOW);
    Serial.println("Heater is OFF");
    temp_flag= false;
  }
}

 void humid_control(){
   //sensing();
   if ((hum<=65.0) && (hum_flag ==false)){
    digitalWrite(fan, LOW);
    Serial.println("Fan is OFF");
    hum_flag= true;
    }
    
   if((hum>=hum_value) && (hum_flag ==true)){
    digitalWrite(fan, HIGH);
    Serial.println("Fan is ON");
    hum_flag = false;
    }
  }

void alarm_system(){
  //sensing();
   if ((hum<50)||(temp>=38)){
     digitalWrite(alarm, HIGH);
      }
   else{
     digitalWrite(alarm, LOW);
        }
  }