#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);  // set the LCD address to 0x27 for a 16 chars and 2 line display
#include <DHT.h>
#define DHTPIN1 2
#define DHTPIN2 10
#define DHTTYPE1 DHT22
#define DHTTYPE2 DHT22  // DHT 22  (AM2302), AM2321
DHT dht1(DHTPIN1, DHTTYPE1);
DHT dht2(DHTPIN2, DHTTYPE1);

//Variables for sensors
int chk;
float hum1;  //Stores humidity value
float temp1; //Stores temperature value
float hum2;  //Stores humidity value
float temp2; //Stores temperature value

const int LED_GREEN = 22;  //Green LED WHEN HEATER OFF 
const int SENSOR_FAILURE_LED= 3;     // CONNECTED TO LED 
const int SENSOR_FAILURE_BUZZER= 4;  
const int POWER_FAILURE= 5;   //CONNECTED TO RELAY THAT CONNCETED WITH BUZZER AND BATTERY 
const int up_key = 6;
const int down_key = 7;
const int RELAY = 8;         //FOR HEATER
const int LED_RED = 9;      //Red LED WHEN HEATER ON
const int SENSOR_COMPARE_BUZZER = 11;
const int SENSOR_COMPARE_LED = 12;
const int over_temp_LED = A0;
const int over_temp_BUZZER= A1;
const int LOW_TEMP_LED= A2;
const int LOW_TEMP_BUZZER= A3;

float SetPoint = 30.0;

unsigned long start;

void setup() {
  lcd.init();  // initialize the lcd
  lcd.backlight();
  Serial.begin(9600);

  pinMode(up_key, INPUT_PULLUP);
  pinMode(down_key, INPUT_PULLUP);
  pinMode(RELAY, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(POWER_FAILURE, OUTPUT);
  pinMode(SENSOR_FAILURE_LED, OUTPUT);
  pinMode(SENSOR_FAILURE_BUZZER, OUTPUT);
  pinMode(SENSOR_COMPARE_BUZZER, OUTPUT); 
  pinMode(SENSOR_COMPARE_LED, OUTPUT);
  pinMode(over_temp_LED, OUTPUT);
  pinMode(over_temp_BUZZER, OUTPUT);
  pinMode(LOW_TEMP_LED,OUTPUT);
  pinMode(LOW_TEMP_BUZZER,OUTPUT);

  dht1.begin();
  dht2.begin();
  
//inialize screen 
  lcd.print("  Vortrex 0.1 ");
  delay(2000);}
int x=0;
void loop() {

  digitalWrite(POWER_FAILURE, HIGH);
 
  temp1 = dht1.readTemperature();
  hum1 = dht1.readHumidity();
  temp2 = dht2.readTemperature();
  hum2 = dht2.readHumidity();

// Check if any reads failed and exit early (to try again).
  if (isnan(temp1) || isnan(hum1))   {
     lcd.print("Failed sensor");
     Serial.print("Failed sensor 1");
     digitalWrite(SENSOR_FAILURE_LED,HIGH); 
     digitalWrite(SENSOR_FAILURE_BUZZER, OUTPUT);
     digitalWrite(RELAY, LOW); 
     digitalWrite(LED_RED, LOW);
     return;
     }
  if (isnan(temp2) || isnan(hum2))  {
     lcd.print("Failed sensor");
     Serial.print("Failed sensor 2");
     digitalWrite(SENSOR_FAILURE_LED,HIGH); 
     digitalWrite(SENSOR_FAILURE_BUZZER, OUTPUT);
     digitalWrite(RELAY, LOW); 
     digitalWrite(LED_RED, LOW);
     return;
     }
  else {  
     digitalWrite(SENSOR_FAILURE_LED,LOW);
     digitalWrite(SENSOR_FAILURE_BUZZER, LOW);
     }

// if one of dht22 have reading out of range 
if ((temp1 < temp2 -5 )||(temp1 -5 > temp2 )) {
  lcd.print("Err2");
  digitalWrite(SENSOR_COMPARE_LED,HIGH);
  digitalWrite(SENSOR_COMPARE_BUZZER,HIGH);
  return;}
else {digitalWrite(SENSOR_COMPARE_BUZZER,LOW);
digitalWrite(SENSOR_COMPARE_LED,LOW);}

//SET POINT 
  if (digitalRead(down_key) == LOW) {
    if (SetPoint > 25.1) {
      SetPoint-=0.1; }}
  if (digitalRead(up_key) == LOW) {
    if (SetPoint < 38.9) {
      SetPoint+=0.1;}}


//Check Temperature is in limit
  if (temp1 > SetPoint) {
    digitalWrite(RELAY, LOW);  //Turn off heater
    digitalWrite(LED_RED, LOW);
    digitalWrite(LED_GREEN, HIGH);}  //Turn on Green LED 
    else {
    digitalWrite(RELAY, 1);  //Turn on heater
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_RED, HIGH);}  //Turn on RED LED
    delay(100);  //Update at every 100mSeconds

//Over Temp
if(temp1 -2 >SetPoint){
  Serial.print("over temp  ");
  digitalWrite(over_temp_LED,HIGH);
  digitalWrite(over_temp_BUZZER,HIGH);
  digitalWrite(RELAY,LOW);
  digitalWrite(LED_RED,LOW);
}
else{digitalWrite(over_temp_LED,LOW);
digitalWrite(over_temp_BUZZER,LOW);}

//Low Temp
if(temp1==SetPoint){x=1;} 
if(temp1 +2 < SetPoint && x==1)
{digitalWrite(LOW_TEMP_LED,HIGH);
digitalWrite(LOW_TEMP_BUZZER,HIGH);
}
else{digitalWrite(LOW_TEMP_LED,LOW);
digitalWrite(LOW_TEMP_BUZZER,LOW);}

//DISPLAY
lcd.setCursor(0, 0);
lcd.print("TEMP:");
lcd.print(temp1, 1);
lcd.print(" C      ");
lcd.setCursor(0, 1);
lcd.print("Set Point:");
lcd.print(SetPoint, 1);
lcd.print(" C");

Serial.print("Humidity1: ");
Serial.print(hum1);
Serial.print(" %, Temp1: ");
Serial.print(temp1);
Serial.println(" Celsius");
Serial.print("Humidity2: ");
Serial.print(hum2);
Serial.print(" %, Temp2: ");
Serial.print(temp2);
Serial.println(" Celsius");
delay(10);}