/*
  SD card datalogger

  This example shows how to log data from three analog sensors
  to an SD card using the SD library.

  The circuit:
   analog sensors on analog ins 0, 1, and 2
   SD card attached to SPI bus as follows (Raspberry Pi Pico):
   ** MISO - pin 4
   ** MOSI - pin 7
   ** CS   - pin 5
   ** SCK  - pin 6

  created  24 Nov 2010
  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

// Include SPI (communication bus) and SD card libraries (for filesystem FAT32)
#include <SPI.h>
#include <SD.h>

// Configure SPI pins
const int _MISO = 16;
const int _MOSI = 19;
const int _CS = 17;
const int _SCK = 18;

// store a byte received from UART
int incomingByte = 0;

// create a file object to interface the write/read to/from sdcard
File myFile;
  
void setup() {
  // Open serial communications and wait for port to open:
  Serial1.begin(115200);
  Serial1.println("Press ENTER to start!");

  delay(500);
  
  // Wait until a newline character is received
  while (incomingByte != '\n') {
    if (Serial1.available() > 0) {
      incomingByte = Serial1.read();
    }
  }
    // print some info to the uart
    Serial1.println("SD card example started!");

  // 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)) {
    Serial1.println("initialization failed!");
    return;
  }
  Serial1.println("initialization done.");
}

void loop() {
   // 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("file.txt", FILE_WRITE);

  // if the file opened okay, write some data:
  if (myFile) {
    // this goes to the uart. check the Serial monitor
    Serial1.print("Writing to file.txt...");
    // this goes to the file "altimeter.txt" inside the sdcard
    myFile.println("testing 1, 2, 3..............................");
    // close the file:
    myFile.close();
    // this goes to the Serial monitor
    Serial1.println("done.");
  } else {
    // if the file didn't open, print an error:
    Serial1.println("error opening file.txt");
  }

  // re-open the file for reading:
  myFile = SD.open("file.txt");
  if (myFile) {
    Serial1.println("Content of file.txt:");

    // read from the file until there's nothing else in it:
    while (myFile.available()) {
      Serial1.write(myFile.read());
    }
    // close the file:
    myFile.close();
  } else {
    // if the file didn't open, print an error:
    Serial1.println("error opening file.txt");
  }

  // List files inside the SD card root directory
  Serial1.println("Listing files in the root directory:");

  File root = SD.open("/");
  if (root) {
    File entry = root.openNextFile();
    while (entry) {
      Serial1.print("  ");
      Serial1.print(entry.name());
      if (entry.isDirectory()) {
        Serial1.println("/");
      } else {
        // Files have sizes, directories do not
        Serial1.print("\t\t");
        Serial1.println(entry.size(), DEC);
      }
      entry = root.openNextFile();
    }
    root.close();
  } else {
    Serial1.println("Failed to open root directory");
  }

  while(1);
}