/*
 Voltaat learn (http://learn.voltaat.com/)
 Link for full tutorial:
 SD Library:
 DHT11 Library:
 Time Library:

 Tutorial: Save values to SD card using Arduino

 The purpose of this sketch is to read the temperature
 in Celsius degrees as well as the humidity of the air
 in percentage from the DHT11 sensor.

 Then save the values in a TXT file
 in the SD card memory every 30 seconds.

 Connections from the Arduino to the breadboard:
 • Arduino GND pin → Breadboard ground line
 • Arduino 5V pin → Breadboard 5V line

 Connections from the DHT11:
 • positive pin→ Breadboard 5V line
 • Out pin → Arduino pin 3
 • Negative pin → Breadboard ground line


 Connections from the SD card module:
 • GND pin → Breadboard ground line
 • VCC pin → Breadboard 5V line
 • MISO pin→ 12
 • MOSI pin→ 11
 • SCK pin → 13
 • CS pin → Arduino pin 4
*/

//This library allows you to communicate with SPI devices
#include "SPI.h"

//include the SD library
#include "SD.h"

//include the time library
#include "TimeLib.h"

//include the DHT sensor Library
#include "DHT.h"

//Define Parameters to DHT function, 3 Refers to digital pin 3 in arduino which you can change with any other digital pin, DHT11 is the sensor type.
DHT dht (3, DHT11);

//Define two variables for Temperature and Humidity.
float Temperature, Humidity;

//Define SD card module cs to arduino digital pin 4
const int cs = 4;

// Commands inside void setup run once.
void setup()
{
 //Initialize the DHT sensor with the begin() method.
 dht.begin();

 //Start the serial monitor at 9600 baud rate (9600 bits per second)
 Serial.begin(9600);

 //Set your current time so that arduino can start from it as real time clock
 //SetTime(hr,min,sec,day,mnth,yr);
 setTime(9, 38, 50, 1, 8, 2022);

 //Function we made to see if the card is present and can be initialized
 Initialize_SDcard();

}

//Commands inside void loop run forever
void loop()
{
 //Fuction we made to print time and date at each line besides values from DHT11 sensor
 dateAndTime();

 //Function we made to read values from DHT11 sensor and print them to serial monitor
 Read_DHT11();

 //Function we made to create a TXT file and save the output to it in the SD card memory
 Write_SDcard();

 //Function we made to see if the card is present and can be initialized
 Initialize_SDcard();

 //delay to get reading from the sensor every 30 seconds
 delay(30000);

}

void dateAndTime()
{
 //Set the system time to the give time t
 time_t t = now();

 //Print to the serial monitor
 Serial.print("Time now: ");
 Serial.print(hour());
 Serial.print(":");
 Serial.print(minute());
 Serial.print(":");
 Serial.print(second());
 Serial.print(" Date: ");
 Serial.print(day());
 Serial.print("/");
 Serial.print(month());
 Serial.print("/");
 Serial.print(year());
}

void Read_DHT11()
{
 //Read the Temperature value from the sensor
 //You can use Temperature = dht.readTemperature(True); to print the temperature value in Fahrenheit.
 Temperature = dht.readTemperature();

 //Read the Humidity value from the sensor
 Humidity = dht.readHumidity();

 //Print to the serial monitor
 Serial.print(" Temperature = ");
 Serial.print(Temperature);
 Serial.print(" ,Humidity = ");
 Serial.print(Humidity);
 Serial.println("%");

}


void Initialize_SDcard()
{
 // see if the card is present and can be initialized
 if (!SD.begin(cs))
 {
   Serial.println(" Card failed, or not present");
   // don't do anything more:
   return;
 }

}
void Write_SDcard()
{
 //Open the file Keep in mind that only one file can be opened at once
 //Consequently, you must close current one before starting a new one
 File dataFile = SD.open("LoggerCD.txt", FILE_WRITE);
 //If the file is available, write to it
 if (dataFile)
 {

   //Set the system time to the give time t
   time_t t = now();

   //Write on the TXT file
   dataFile.print("Time now: ");
   dataFile.print(hour());
   dataFile.print(":");
   dataFile.print(minute());
   dataFile.print(":");
   dataFile.print(second());
   dataFile.print(" Date: ");
   dataFile.print(day());
   dataFile.print("/");
   dataFile.print(month());
   dataFile.print("/");
   dataFile.print(year());
   dataFile.print(" Temperature: ");
   dataFile.print(Temperature); //Store date on SD card
   dataFile.print(" ,"); //Move to next column using a ","
   dataFile.print("Humidity ");
   dataFile.print(Humidity); //Store date on SD card
   dataFile.print("%");
   dataFile.println(); //End of Row move to next row
   dataFile.close(); //Close the file
 }
 else

   //Print to serial monitor
   Serial.println(" SD card writing failed");
}