// UH 5COM2004
// Practical 3 - DHT Sensor
// 3.1 - Library
// 
// Use a DFU Temperature and Humidity Sensor
// Make use of the DHT library
// https://github.com/adafruit/DHT-sensor-library
// https://randomnerdtutorials.com/esp32-dht11-dht22-temperature-humidity-sensor-arduino-ide/


#include "DHT.h"

#define DHTPIN 14     // Digital pin connected to the DHT sensor
// Feather HUZZAH ESP8266 note: use pins 3, 4, 5, 12, 13 or 14 --
// Pin 15 can work but DHT must be disconnected during program upload.


//#define DHTTYPE DHT11   // DHT 11
#define DHTTYPE DHT22   // DHT 22 (AM2302), AM2321
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// initialise the sensor
DHT dht(DHTPIN, DHTTYPE);

// container variables
float humidity;
float temp_c;
float temp_f;

float hic;  // heat index for celsius temp
float hif;  // heat index for fahrenheit temp

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println(F("DHTxx test!"));

  dht.begin();

}

void loop() {
  // put your main code here, to run repeatedly:
  // wait 2s between measurements
  delay(2000);

  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  humidity = dht.readHumidity();
  // Read temperature as Celsius (the default)
  temp_c = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  temp_f = dht.readTemperature(true);

  // Check if any reads failed and exit early (to try again).
  if (isnan(humidity) || isnan(temp_c) || isnan(temp_f)) {
    Serial.println(F("Failed to read from DHT sensor!"));
    return;
  }

  // Compute heat index in Fahrenheit (the default)
  float hif = dht.computeHeatIndex(temp_f, humidity);
  // Compute heat index in Celsius (isFahreheit = false)
  float hic = dht.computeHeatIndex(temp_c, humidity, false);

  Serial.print(F("Humidity: "));
  Serial.print(humidity);
  Serial.print(F("%  Temperature: "));
  Serial.print(temp_c);
  Serial.print(F("C "));
  Serial.print(temp_f);
  Serial.print(F("F  Heat index: "));
  Serial.print(hic);
  Serial.print(F("C "));
  Serial.print(hif);
  Serial.println(F("F"));
}