#include "DHT.h" //a library used to read the DHT22 sensor.
#include <math.h>
#define sensor 4

DHT dht(sensor, DHT22);
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(sensor, INPUT);
}

String temp_calculate(){
  float temperature = 0;
  float total_temp = 0;
  float avg_temp;
  float arr[10];
  float sum_x;
  float deviation; 
  float max_temp = -40;
  float min_temp = 80;
  for (int i=0; i<10; i++){
    delay(1000);
    temperature = dht.readTemperature();
    if(!isnan(temperature)){
      Serial.println("Temperature: " + String(temperature));
      total_temp+= temperature;
      if (temperature > max_temp){
        max_temp = temperature;
      }
      if (temperature < min_temp){
        min_temp = temperature;
      }
      arr[i] = temperature;
    }
    else{
      i-=1;
      continue;
    }
  } 
  avg_temp = total_temp / 10;
  for(int i=0; i<10; i++){
    float x;
    x = (arr[i] - avg_temp) * (arr[i] - avg_temp);
    sum_x += x;
  }
  deviation = sqrt(sum_x/10);
  String out = "Minimum temperature: " + String(min_temp) + "\nMaximum temperature: " + String(max_temp) + "\nAverage temperature: " + String(avg_temp) + "\nStandard deviation: " + String(deviation);
  return out;
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println(temp_calculate());
}