#include <SPI.h> // Include SPI library needed for the SD card
#include <SD.h> // Include SD library
#include <DHT.h> // Include DHT sensor library

File dataFile;

#define DHTPIN 2 // DHT22 data pin is connected to Arduino pin 2
#define DHTTYPE DHT22 // DHT22 sensor is used
DHT dht(DHTPIN, DHTTYPE); // Initialize DHT library

// declare variable names
float hum; // humidity range is 0 - 100%
float temp; // temp range -40 to 125 degrees celsius

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600); // Initializing Serial Monitor
  SD.begin(); // Initializing SD Card
  dht.begin(); // Initializing DHT sensor
}

void loop() {
  // put your main code here, to run repeatedly:
  hum = dht.readHumidity(); // Read humidity
  temp= dht.readTemperature(); // Read temperature

  Serial.print("Humidity: ");
  Serial.print(hum);
  Serial.print("%, Temperature: ");
  Serial.print(temp);
  Serial.print(" Degrees Celsius");
  Serial.print("\n");

  // open SD card file (data.txt)
  dataFile = SD.open("data.txt", FILE_WRITE);

  // Write data to SD card file (data.txt)
  dataFile.print("Humidity: ");
  dataFile.print(hum);
  dataFile.print("%, Temperature: ");
  dataFile.print(temp);
  dataFile.print(" Degrees Celsius");
  dataFile.print("\n");
  dataFile.close();
  // delay in between reads for stability
  delay(1000);
}