  
  

#include <SPI.h>

#include <SD.h>

  

File myFile;

  

void setup() {

  // Open serial communications and wait for port to open:

  Serial.begin(9600);

  

  Serial.print("Initializing SD card...");

  

  if (!SD.begin(15)) {

    Serial.println("initialization failed!");

    return;

  }

  Serial.println("initialization done.");

  

  // open the file. note that only one file can be open at a time,

  // so you have to close this one before opening another.

  myFile = SD.open("test.txt", FILE_WRITE);

  Serial.print("asfd");

  // if the file opened okay, write to it:

  if (myFile) {

    Serial.print("Writing to test.txt...");

    myFile.println("testing 1, 2, 3.");

    // close the file:

    myFile.close();

    Serial.println("done.");

  } else {

    // if the file didn't open, print an error:

    Serial.println("error opening test.txt");

  }

  Serial.print("asfd1");

  

  // re-open the file for reading:

  myFile = SD.open("test.txt");

  if (myFile) {

    Serial.println("test.txt:");

  

    // read from the file until there's nothing else in it:

    while (myFile.available()) {

      Serial.write("1 - ");

      Serial.write(myFile.read());

    }

    // close the file:

    myFile.close();

  } else {

    // if the file didn't open, print an error:

    Serial.println("error opening test.txt");

  }

    Serial.print("asfd2");

  

  pinMode(D4, INPUT);

}

  

void loop() {

  byte val = digitalRead(D4);

  if (val == HIGH) {

    Serial.println("Closed");

  } else {

    Serial.println("Open");

  }

  

  delay(500);

}