#include <DHT.h> // include the library for our sensor

#define DHTPIN 2 // define the pin where the sensor is connected
#define DHTTYPE DHT22 // define the type of the sensor

DHT dht(DHTPIN, DHTTYPE); // class of the library to create an object

void setup() { // function to start when we power the board or reseting
  Serial.begin(115200); // initialization
  pinMode(13, OUTPUT); // for the alarm led
  dht.begin(); // initialization of the sensor
  delay(1000); // delay 1 second to skip the unstable phase
  Serial.println("AM2302 Is Ready!"); // to see that the sensor connected successfully
  // print the headers
  Serial.print("Time (ms), Humidity (%), Temperature (C), Sense Temperature (C)");
  // check the led
  digitalWrite(13, HIGH); // light led
  delay(500);
  digitalWrite(13, LOW); // close led
}

void loop() { // function that runs again and again for ever after the setup until we reset or cut off the power
  float humidity=dht.readHumidity(); // read the humidity measumerement
  float temperature=dht.readTemperature(); // read the temperature measurement
  float sense=dht.computeHeatIndex(temperature, humidity, false); // calculate the sense temperature due to humidity

  // print time humidity, temperature and sense of temperature values
  Serial.print(millis());
  Serial.print(", ");
  Serial.print(humidity);
  Serial.print(", ");
  Serial.print(temperature);
  Serial.print(", ");
  Serial.println(sense); // print with new line at the end

  // for extreme temperatures give an alarm
  if (temperature>=40 || temperature<=0)
  {
    alert_blink();
  }
  else
  {
    digitalWrite(13, LOW); // to be sure the led if off
    delay(2000); // take a measure every 2 seconds
  }
}

void alert_blink() // alarm function for the led blink
{ // total delay same as if we don't have an alarm (can be different)
    digitalWrite(13, HIGH);
    delay(400);
    digitalWrite(13, LOW);
    delay(400);
    digitalWrite(13, HIGH);
    delay(400);
    digitalWrite(13, LOW);
    delay(400);
    digitalWrite(13, HIGH);
    delay(400);
    digitalWrite(13, LOW);
}