B4R Question What max file size to SD card your used?

Private Sub SaveToLog As Boolean
    Log("Wait..")
    Dim millis1 As ULong = Millis
    Dim j, i As UInt
    For j = 1 To 3
        Dim fn As String = GenerateFileName(j)
        For i = 1 To 5000
            Dim a() As Byte = GenerateFileLine(i)
            WriteString(fn, a)
        Next
        Log(fn, " saved OK")
    Next
    Dim millis2 As ULong = Millis
    Dim delta As Float = (millis2 - millis1)/1000
    Log("Saved log file OK: ", NumberFormat(delta, 1, 3))
    Return True
End Sub

Sub GenerateFileName(i As UInt) As String
    Dim fn As String = JoinStrings(Array As String("/log_", NumberFormat(i,4,0), ".dat"))
    Return fn
End Sub

Sub GenerateFileLine(i As UInt) As String
    Dim a As String = JoinStrings(Array As String(NumberFormat(i,10,0), ";", "Column_", NumberFormat(i, 2, 0), CRLF))
    Return a
End Sub

Sub WriteString(key_string() As Byte, value() As Byte)
    Dim source As KeyValueType
    source.key = key_string
    source.value = value
    RunNative("save_csv_line", source)
    'Log("Saved to file")
End Sub

#if C
#include "FS.h"
#include "SD.h"
#include "SPI.h"

B4R::Object returnvalue_esp_sp;

void writeFile(fs::FS &fs, const char *path, const char *message) {
  Serial.printf("Writing file: %s\n", path);

  File file = fs.open(path, FILE_WRITE);
  if (!file) {
    Serial.println("Failed to open file for writing");
    return;
  }
  if (file.print(message)) {
    Serial.println("File written");
  } else {
    Serial.println("Write failed");
  }
  file.close();
}

void appendFile(fs::FS &fs, const char *path, const char *message) {
  //Serial.printf("Appending to file: %s\n", path);

  File file = fs.open(path, FILE_APPEND);
  if (!file) {
    Serial.println("Failed to open file for appending");
    return;
  }
  if (file.print(message)) {
    //Serial.println("Message appended");
  } else {
    Serial.println("Append failed");
  }
  file.close();
}

B4R::Object* setup_sd(B4R::Object* o){
    bool begun = SD.begin();
    if (!begun) {
        //Serial.println("Card Mount Failed");
        return returnvalue_esp_sp.wrapNumber((byte)0);
    }else{
        return returnvalue_esp_sp.wrapNumber((byte)1);
    }
}

void save_csv_line(B4R::Object* passedvar){
    _keyvaluetype* tmp = (_keyvaluetype*)B4R::Object::toPointer(passedvar); //structure from B4R
 
    B4R::Array* b = tmp->key;
    char* c = (char*)b->data; //file name, do not forget slash "/file.txt"
    //String key = (String)c;
 
    B4R::Array* b2 = tmp->value;
    char* c2 = (char*)b2->data; //test line for saving to file
    //String value = (String)c2;

    appendFile(SD, c, c2);
}

B4R::Object* freespace_sd(B4R::Object* o){
    float result;
    uint64_t total = SD.totalBytes() / (1024 * 1024);
    Serial.printf("totalBytes: %llu MB\n", total);
    uint64_t used = SD.usedBytes() / (1024 * 1024);
    Serial.printf("usedBytes: %llu MB\n", used);
    result = ((float)total - (float)used) / (float)total * 100;
   
       return returnvalue_esp_sp.wrapNumber((float)result);
}
#End If