title: How do I write integers to a micro SD card on an Arduino
body: <p>How do I get the Arduino to write the measurement data onto the micro SD card when the write function only accepts integers?</p>
  
  <pre><code>#include &lt;SD.h&gt;
  #include &lt;SPI.h&gt;
  
  int CS_PIN = 10;
  int ledPin = 13;
  int EP =9;
  
  
  
  File file;
  
  void setup()
  {
  
    Serial.begin(9600);
    pinMode(ledPin, OUTPUT);
    pinMode(EP, INPUT);
  
    initializeSD();
  
  
  
  }
  
  
  void loop(){
    long measurement =TP_init();
    delay(50);
   // Serial.print("measurment = ");
    Serial.println(measurement);
  
    createFile("test.txt");
    writeToFile(measurement);
    closeFile();
  }
  
  
  
  long TP_init(){
    delay(10);
    long measurement=pulseIn (EP, HIGH);  //wait for the pin to get HIGH and   returns measurement
    return  String(measurement);
  
  }
  
  
  
  
  
  void initializeSD()
  {
    Serial.println("Initializing SD card...");
    pinMode(CS_PIN, OUTPUT);
  
    if (SD.begin())
    {
      Serial.println("SD card is ready to use.");
    } else
    {
      Serial.println("SD card initialization failed");
      return;
    }
  }
  
  int createFile(char filename[])
  {
    file = SD.open(filename, FILE_WRITE);
  
    if (file)
    {
      Serial.println("File created successfully.");
      return 1;
    } else
    {
      Serial.println("Error while creating file.");
      return 0;
    }
  }
  
  int writeToFile(char text[])
  {
    if (file)
    {
      file.println(text);
      Serial.println("Writing to file: ");
      Serial.println(text);
      return 1;
    } else
    {
      Serial.println("Couldn't write to file");
      return 0;
    }
  }
  
  void closeFile()
  {
    if (file)
    {
      file.close();
      Serial.println("File closed");
    }
  }
  
  int openFile(char filename[])
  {
    file = SD.open(filename);
    if (file)
    {
      Serial.println("File opened with success!");
      return 1;
    } else
    {
      Serial.println("Error opening file...");
      return 0;
    }
  }
  
  String readLine()
  {
    String received = "";
    char ch;
    while (file.available())
    {
      ch = file.read();
      if (ch == '\n')
      {
        return String(received);
      }
      else
      {
        received += ch;
      }
    }
    return "";
  }
  </code></pre>