CPP: SDCard - lvidarte/esp8266 GitHub Wiki

/*
  SD card basic file example
  https://www.arduino.cc/en/Reference/SD
  This example shows how to create and destroy an SD card file
  The circuit:
  * SD card attached to SPI bus as follows:
  ** MOSI - D7 - 13
  ** MISO - D6 - 12
  ** CLK  - D5 - 14
  ** CS   - D8 - 15
  SPI Ref: https://www.arduino.cc/en/Reference/SPI
  The ESP8266 has 2 SPI interfaces (called "SPI" and "HSPI" in the source code
  and the pin descriptions). The SPI register header file and the source code
  suggest that both interfaces have identical register sets, which are just
  located at different base addresses.
  */

#include <Arduino.h>
#include <SPI.h>
#include <SD.h>

File myFile;

void setup ()
{
  // Open serial communications and wait for port to open:
  Serial.begin(115200);

  Serial.print("Initializing SD card...");
  if (!SD.begin(4))
  {
    Serial.println("initialization failed!");
    return;
  }
  Serial.println("initialization done.");

  // Check if file exists
  if (SD.exists("example.txt"))
  {
    Serial.println("example.txt exists.");
  } else {
    Serial.println("example.txt doesn't exist.");
  }

  // Open file for write
  myFile = SD.open("example.txt", FILE_WRITE);
  myFile.println("hello world");
  myFile.close();

  // Open file for read
  Serial.println("reading example.txt");
  myFile = SD.open("example.txt");
  if (myFile)
  {
    while (myFile.available())
    {
      Serial.write(myFile.read());
    }
    myFile.close();
  }
  else
  {
    Serial.println("error opening example.txt");
  }

  // Delete file
  Serial.println("Removing example.txt...");
  SD.remove("example.txt");

  if (SD.exists("example.txt")) {
    Serial.println("example.txt exists.");
  } else {
    Serial.println("example.txt doesn't exist.");
  }
}

void loop ()
{
}