#define ntc_pin A0         // Pin,to which the voltage divider is connected
//#define vd_power_pin 2     // 5V for the voltage divider
#define nominal_resistance 10000       //Nominal resistance at 25⁰C
#define nominal_temeprature 25         // temperature for nominal resistance (almost always 25⁰ C)
#define samplingrate 5    // Number of samples
#define beta 3950         // The beta coefficient or the B value of the thermistor (usually 3000-4000) check the datasheet for the accurate value.
#define Rref 10000        //Value of  resistor used for the voltage divider

#include <DHT.h>
#include <DHT_U.h>

#include "DHT.h"
#define DHTPIN 2     // Digital pin connected to the DHT sensor
// Uncomment whatever type you're using!
//#define DHTTYPE DHT11   // DHT 11
#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321
//#define DHTTYPE DHT21   // DHT 21 (AM2301)
DHT dht(DHTPIN, DHTTYPE);

int samples = 0;          //array to store the samples

void DHT(){

      // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  float f = dht.readTemperature(true);

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

  // Compute heat index in Fahrenheit (the default)
  float hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  float hic = dht.computeHeatIndex(t, h, false);

  Serial.print(F("Humidity: "));
  Serial.println(h);
  Serial.print(F("DHT Temperature: "));
  
  Serial.print(t);
  Serial.println(F("°C "));
  Serial.print(f);
  Serial.print(F("°F  Heat index: "));
  Serial.print(hic);
  Serial.print(F("°C "));
  Serial.print(hif);
  Serial.println(F("°F"));

}
void setup() {
  Serial.begin(9600);
  Serial.println(F("DHTxx test!"));

  dht.begin();
}

void loop(void) {
  

  uint8_t i;
  float average;

  samples = 0;
  
  // take voltage readings from the voltage divider

//  digitalWrite(vd_power_pin, HIGH);

  for (i = 0; i < samplingrate; i++) {
    samples += analogRead(ntc_pin);
    delay(10);
  }

//  digitalWrite(vd_power_pin, LOW);
  average = 0;
  average = samples / samplingrate;
  Serial.println("\n \n");
  Serial.print("ADC readings ");
  Serial.println(average);
  
  // Calculate NTC resistance
  average = 1023 / average - 1;
  average = Rref / average;
  Serial.print("Thermistor resistance ");
  Serial.println(average);
  
  float temperature;
  temperature = average / nominal_resistance;     // (R/Ro)
  temperature = log(temperature);                  // ln(R/Ro)
  temperature /= beta;                   // 1/B * ln(R/Ro)
  temperature += 1.0 / (nominal_temeprature + 273.15); // + (1/To)
  temperature = 1.0 / temperature;                 // Invert
  temperature -= 273.15;                         // convert absolute temp to C  --->  Kelvin To Celsius
  
  Serial.print("NTC Temperature ");
  Serial.print(temperature);
  Serial.println(" *C");
  delay(2000);
  DHT();
}