/* DHT-22 sensor with 12c 16x2 LCD with Arduino uno
   Temperature and humidity sensor displayed in LCD
   based on: http://www.ardumotive.com/how-to-use-dht-22-sensor-en.html and
   https://www.ardumotive.com/i2clcden.html for the i2c LCD library by Michalis Vasilakis
   Recompile by adhitadhitadhit
   Notes: use LCD i2c Library from link above, i'm not sure why but new Liquidcristal library from Francisco Malpartida  isn't working for me
   other thing, check your */

//Libraries
#include <dht.h> // sensor library using lib from https://www.ardumotive.com/how-to-use-dht-22-sensor-en.html
#include <LiquidCrystal_I2C.h> // LCD library using from  https://www.ardumotive.com/i2clcden.html for the i2c LCD library 
#include <Wire.h> 
dht DHT;

//Constants
#define DHT22_PIN 2     // DHT 22  (AM2302) - pin used for DHT22 
LiquidCrystal_I2C lcd(0x27,20,4);  // set the LCD address to 0x27 after finding it from serial monitor (see comment above) for a 16 chars and 2 line display

//Variables
int hum;  //Stores humidity value
int temp; //Stores temperature value
const int RELAY1=10; //Red LED
const int RELAY2=11; //Green LED
const int RELAY3=12; //Lock Relay or motor
 const int up_key=3;
 const int down_key=4;
int SetPoint=30;

void setup()
{
  pinMode(RELAY1,OUTPUT);
  pinMode(RELAY2,OUTPUT);  
  pinMode(RELAY3,OUTPUT);  
  pinMode(up_key,INPUT);
  pinMode(down_key,INPUT);
  digitalWrite(up_key,LOW);
  digitalWrite(down_key,LOW);
  digitalWrite(RELAY1,LOW);     //Red LED On
  digitalWrite(RELAY2,LOW);       //Turn off Relay
  digitalWrite(RELAY3,LOW);       //Turn off Relay
   
    Serial.begin(9600);
    lcd.init();                      // initialize the lcd 
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setBacklight(HIGH);
}

void loop()
{
    int chk = DHT.read22(DHT22_PIN);
    //Read data and store it to variables hum and temp
    hum = DHT.humidity;
    temp= DHT.temperature;
    //Print temp and humidity values to LCD
    lcd.setCursor(0,0);
    lcd.print("Homoditi:");
    lcd.print(hum);
    lcd.print("%");
    lcd.setCursor(0,1);
    lcd.print("Temperatur:"); 
    lcd.print(temp);
    lcd.println("C");
    delay(2000); //Delay 2 sec between temperature/humidity check.
//Get user input for setpoints  
  if(digitalRead(down_key)==HIGH)
  {
    if(SetPoint>0)
    {
      SetPoint--;    
    }
  }
  if(digitalRead(up_key)==HIGH)
  {
    if(SetPoint<100)
    {
      SetPoint++;
    }
  }

//Display Set point on LCD
  lcd.setCursor(0,2);
  lcd.print("Set Point:");
  lcd.print(SetPoint);
  lcd.print("C   ");

//Check Temperature is in limit
if(temp > SetPoint)
{
   digitalWrite(RELAY1,LOW);    //Turn off heater
   digitalWrite(RELAY2,LOW);
   digitalWrite(RELAY3,HIGH);  //Turn on Green LED
}
else
{
  digitalWrite(RELAY1,HIGH);    //Turn on heater
  digitalWrite(RELAY2,LOW);
  digitalWrite(RELAY3,HIGH);
  delay(2000);
   //Turn on RED LED  
}


}
//=================================================================