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[SOLVED] Weird problem in interfacing between Arduino Uno and SD card

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mamech

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hello everyone

I have a weird problem. I am trying to interface an Arduino Uno with an SD card. The code is made to produce a new file every timer interval. The logic seemed simple to me, but the results are not logical at all!
this is the code:
Code:
#include <SPI.h>  //SPI communication protocol library
#include <SD.h>  //SD card interface library

double File_name_counter=1;
String Fixed_File_Name = "ex";
String Variable_File_Name = "";
String Extension = ".txt";
char temp[9] = "ex.txt";
int i=0;
int soft_counter =0;
void setup()
{
  // Open serial communications:
  Serial.begin(9600);
  
  Serial.print("Initializing SD card...");
  pinMode(10, OUTPUT);  // Comment from Arduino page: This can be the hardware SS pin - pin 10 (on most Arduino boards) or 
                        // pin 53 (on the Mega) - or another pin specified in the call to SD.begin(). Note that
                        // even if you don't use the hardware SS pin, it must be left as an output or the SD library won't work.

  if (!SD.begin(4))  // begin SD proces, and make the SS/CS pin to be on pin 4, and check if it returns true or false
  {
    Serial.println("initialization failed!");
    return;
  }
  Serial.println("initialization done.");

  delay(3000);

}


void loop()
{
  
  File myFile;
  myFile = SD.open(temp, FILE_WRITE);
 if (myFile) {
    Serial.println("Writing to the file");
    i++;
    myFile.println(i);
    myFile.close();
    Serial.println("done.");
  } else {
    // if the file didn't open, print an error:
    Serial.println("error opening file");
  }
  delay(1000);      //delay
  
  soft_counter++;
  if(soft_counter>30)
  {
    Variable_File_Name= Fixed_File_Name+File_name_counter+Extension;  // construct new file name
    Variable_File_Name.toCharArray(temp,9) ;   // convert file name from String to CharArray

    File_name_counter++;
    soft_counter=0;
  }
}


This code writes only one file with incrementing numbers in it, and when the part after delay function begins , the serial monitor gives several times :
error opening file
error opening file
error opening file


can any one tells me what is the problem in this code? I made numerous modifications nut no logical response.
 

hi m,
I would add a file name check/debug after this code in order to ensure a correct name construct.

Variable_File_Name= Fixed_File_Name+File_name_counter+Extension; // construct new file name
Variable_File_Name.toCharArray(temp,9) ; // convert file name from String to CharArray
Serial.println(Variable_File_Name);

E
 

thanks for advice, but before I made this equation, I have already made this step for checking to be sure that the output is really a char array that contains the correct file name that increment with incrementing of variable "File_name_counter"
 

hi m,
I have programmed my working Arduino Mega and SD Shield data logger with your Sketch.
For some reason it reports 'error opening file', I will relook at the cause, let you know what I find.

I have reduced the software counter in order to get the constructed FileName more often.

Note when the FileNameCounter is Double , the FileName has 1.00 as the Index which means two 'DPs!' in the FileName.
Changing the Double Long gives an acceptable FileName construct.
Ref the attached images.

E

- - - Updated - - -

hi m,
The above 'Arduino Mega and SD Shield data logger', should read Arduino UNO and SD Shield data logger.
I will change over to the MEGA later.
E

- - - Updated - - -

hi,
The attached EDA_SD1.txt file works OK on a UNO, I have verified that the data is being written to the SD Card.
Change the file extension to '.ino'.
Attached is a clip of the Serial data.
E
 

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Reactions: mamech

    mamech

    Points: 2
    Helpful Answer Positive Rating
it works now, thank you very much! I was about to be mad because I did not think that data type can cause all of this mess.
 

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