/*
  SD card basic file example

  This example shows how to create and destroy an SD card file
  The circuit:
   SD card attached to SPI bus as follows:
   ** MISO - pin 4
   ** MOSI - pin 7
   ** CS   - pin 5
   ** SCK  - pin 6

  created   Nov 2010
  by David A. Mellis
  modified 9 Apr 2012
  by Tom Igoe

  This example code is in the public domain.

*/

// This are GP pins for SPI0 on the Raspberry Pi Pico board, and connect
// to different *board* level pinouts.  Check the PCB while wiring.
// Only certain pins can be used by the SPI hardware, so if you change
// these be sure they are legal or the program will crash.
// See: https://datasheets.raspberrypi.com/picow/PicoW-A4-Pinout.pdf
const int _MISO = 4;
const int _MOSI = 7;
const int _CS = 5;
const int _SCK = 6;

#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...");

  // Ensure the SPI pinout the SD card is connected to is configured properly
  SPI.setRX(_MISO);
  SPI.setTX(_MOSI);
  SPI.setSCK(_SCK);

  if (!SD.begin(_CS)) {
    Serial.println("initialization failed!");
    return;
  }
  Serial.println("initialization done.");

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

  // open a new file and immediately close it:
  Serial.println("Creating example.txt...");
  myFile = SD.open("example.txt", FILE_WRITE);
  myFile.close();

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

  // delete the 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() {
  // nothing happens after setup finishes.
}