/*
 * Created by ArduinoGetStarted.com
 *
 * This example code is in the public domain
 *
 * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-heating-system
 */

// DHT22 Initial
#include "DHT.h"
#define DHTPIN 15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

#define RELAY_PIN   33  // Arduino pin connected to relay which connected to heating element

int temperature_detection () {
  delay(1000);
  float t = dht.readTemperature();

  if (isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
  }

  if (t < 23) {
    Serial.println("Temperature too low. It is: " + String(t));
    return 1;
  }

  if (t >= 23 && t <= 25) {
    Serial.println("Temperature is good. It is: " + String(t));
    return 2;
  }

  if (t > 25) {
    Serial.println("Temperature too high. It is: " + String(t));
    return 3;
  }
}


void setup() {
  Serial.begin(9600); // initialize serial
  // DHT22 Setup
  dht.begin();
  pinMode(RELAY_PIN, OUTPUT); // initialize digital pin as an output
}

void loop() {
  if (temperature_detection() == 1) {
    Serial.println("The heating element is turned on");
    digitalWrite(RELAY_PIN, HIGH); // turn on
  }
  else if (temperature_detection() == 2 || temperature_detection() == 3)
    Serial.println("The heating element is turned off");
    digitalWrite(RELAY_PIN, LOW); // turn off
  delay(1000);
}