#include <DHT.h>  // Include the DHT sensor library

#define DHTPIN 15   // Define the GPIO pin where the DHT sensor is connected
#define DHTTYPE DHT22  // Define the type of DHT sensor (DHT22)
DHT dht(DHTPIN, DHTTYPE);  // Initialize the DHT sensor

float temperature_c;  // Variable to store the current temperature reading
#define ntemp 10  // Number of temperature readings to store
float temp[ntemp];  // Array to store temperature readings
static int measurement_counter = 0;  // Counter to track number of measurements

// Function to get the minimum temperature from stored readings
float getMin() {
    float result = temp[0];
    for (int i = 1; i < ntemp; i++) {
        if (temp[i] < result) {
            result = temp[i];
        }
    }
    return result;
}

// Function to get the maximum temperature from stored readings
float getMax() {
    float result = temp[0];
    for (int i = 1; i < ntemp; i++) {
        if (temp[i] > result) {
            result = temp[i];
        }
    }
    return result;
}

// Function to calculate the average temperature
float getAvg() {
    float result = 0.0;
    for (int i = 0; i < ntemp; i++) {
        result += temp[i];
    }
    return (result / ntemp);
}

// Function to calculate the standard deviation of temperature readings
float getStdv() {
    float avg = getAvg();
    float deviation = 0.0;
    float sumsqr = 0.0;
    for (int i = 0; i < ntemp; i++) {
        deviation = temp[i] - avg;
        sumsqr += sq(deviation);
    }
    float variance = sumsqr / ntemp;
    return sqrt(variance);
}

// Function to initialize the temperature array with zeros
void initialisation() {
    for (int i = 0; i < ntemp; i++) {
        temp[i] = 0.0;
    }
}

// Function to update the counter and process data when enough readings are collected
void addCounter() {
    measurement_counter++;
    if (measurement_counter >= ntemp) {
        printProcessedData();  // Print calculated statistics
        resetCounter();  // Reset the counter
    }
}

// Function to reset the measurement counter
void resetCounter() {
    measurement_counter = 0;
}

// Function to add a new temperature reading to the array
void addReading(float t) {
    temp[measurement_counter] = t;  // Store the temperature reading
    addCounter();  // Update counter and check if processing is needed
}

// Function to print the processed temperature data (Min, Max, Avg, Std Dev)
void printProcessedData() {
    Serial.print("Min: ");
    Serial.print(getMin());
    Serial.print(", Max: ");
    Serial.print(getMax());
    Serial.print(", Avg: ");
    Serial.print(getAvg());
    Serial.print(", Stdev: ");
    Serial.println(getStdv());
}

void setup() {
    Serial.begin(9600);  // Start serial communication
    dht.begin();  // Initialize the DHT sensor
    initialisation();  // Initialize the temperature array
}

void loop() {
    temperature_c = dht.readTemperature(false);  // Read temperature in Celsius
    addReading(temperature_c);  // Store and process the reading
    Serial.print("Current temperature: ");
    Serial.println(temperature_c);
    delay(1000);  // Waits for 1 second before taking the next reading
}