#include <DHT.h>
#include <Wire.h> // библиотека для управления устройствами по I2C 
#include <LiquidCrystal_I2C.h> // подключаем библиотеку для QAPASS 1602

#define DHTTYPE DHT22

#define DHTPIN 3
#define relayPin_warm 2
#define relayPin_cold 11

DHT dht(DHTPIN, DHTTYPE);

float hum;
float temp;
byte temp_status = 0;
unsigned long timer = 0;

/*
 start - temp_status = 0
 too cold - temp_status = 1
 too warm - temp_status = 2
 */

LiquidCrystal_I2C lcd(0x27,16,2);


void setup() {
   Serial.begin(9600);
   
   pinMode(relayPin_warm, OUTPUT);
   pinMode(relayPin_cold, OUTPUT);

   dht.begin();   
   
   lcd.begin(16, 2);
}


void loop(){  
  if (millis() - timer > 1000) {
    timer = millis();
    
    hum = dht.readHumidity();
    temp = dht.readTemperature();
     // temp = 15;
     if (temp < 18) { 
        if (temp_status != 1) {
           if (temp_status == 2) {
              digitalWrite(relayPin_warm, LOW); // disable warm relay
           }
           
           digitalWrite(relayPin_cold, HIGH); // enable cold relay
           temp_status = 1;
        }
     }
     else if (temp > 21) {
        if (temp_status != 2) {  
           if (temp_status == 1) {
              digitalWrite(relayPin_cold, LOW); // disable cold relay
           }
           
           digitalWrite(relayPin_warm, HIGH); // enable warm relay
           temp_status = 2;
        }
        
     }
     else {
        if (temp_status) {
           if (temp_status == 1) {
              digitalWrite(relayPin_cold, LOW); // disable cold relay
           }
           else if (temp_status == 2) {
              digitalWrite(relayPin_warm, LOW); // disable warm relay
           }
           temp_status = 0;
        }
     }
      
    lcd.setCursor(0, 0);           // working with 
    lcd.print("15:51 28.11.2022");
    lcd.setCursor(0, 1);   // lcd dispaly 
    lcd.print("t: ");   // 
    lcd.print(temp);        // 
    lcd.print(' ');
    lcd.print("h: ");    //
    lcd.print(hum);        //
  }
}