7 replies to this topic

[NoxiaZ]

Hey,

 

Im using framework 4.3 and trying to write to an SD card, but gives me an error:

 

An unhandled exception of type 'System.NotSupportedException' occurred in System.IO.dll

 

on this line:

 

Stream st = new FileStream(@"SDtest.txt", FileMode.OpenOrCreate);

 

Whats wrong? :S

[Chris Walker]

Hi NoxiaZ, First thing...please add a "" before "SD", making it "SD". Beyond that: is your Netduino Plus 2 detecting the SD card (i.e. you see a "SD" folder when you do GetDirectories on @"")? Can you see the files on the SD card using GetFiles? The SD code in 4.3.1 should be identical to 4.2.2.2. We ran our standard SD card tests (from our test jigs) on the firmware before posting it...so the basic SD functionality at minimum is working in the firmware. Chris

[NoxiaZ]

Hi Chris,

 

i have tried everything nearly for writing.

 

  try
  {
  string[] directories = Directory.GetDirectories("");
  string dir = "";
  Debug.Print("Directories count: " + directories.Length);
  for (int i = 0; i < directories.Length; i++)
  {
  Debug.Print("Directory: " + directories[i]);
  if (directories[i].ToLower().IndexOf("sd") >= 0)
  {
  dir = directories[i];
  Debug.Print("Found: " + dir);
  }
  }

  Debug.Print("Finding files");
  string[] files = Directory.GetFiles(dir);
  Debug.Print("File count: " + files.Length);
  for (int i = 0; i < directories.Length; i++)
  {
  Debug.Print("Files: " + files[i]);
  }

  Stream st = new FileStream(dir + @"Log.txt", FileMode.OpenOrCreate);
  }
  catch (Exception ex)
  {
  Debug.Print("Error: " + ex);
  }

 

And this is the log:

 

Directories count: 1
Directory: SD
Found: SD
Finding files
A first chance exception of type 'System.NotSupportedException' occurred in Microsoft.SPOT.IO.dll
A first chance exception of type 'System.IO.IOException' occurred in System.IO.dll
Error: System.IO.IOException

[Chris Walker]

Hi NoxiaZ, Please try reformatting your card on your PC. BTW, what size is the card? <=2GB? Or a larger SDHC card? Chris

[NoxiaZ]

I just reformatting it, and its a SDHC 8GB - Is that a problem? :/

[Kip]

Netduino doesn't support SDHCs, just plain old SDs

[NoxiaZ]

Ohh

 

And thanks for you answer

[RayHAz]

Would be nice to have one central location where all the answers are laid out simply.  There's a lot of info out there, but it's scattered, and a lot of it is wrong (good-intentioned people who are coding and testing with bad results).  Here's what I think I know so far...

 

I'm using a Netduino Plus 2, programming in VB with Visual Studio 2013, but using MF 4.2 (not 4.3).  I've successfully written code to flash LED's, move servos, accept TCP/IP connections, etc.

 

Like most people, I thought just any old micro form-factor card would work.  I found a 2GB SD (non-SDHC) micro SanDisk card for under $6 (I added to my Amazon list here http://astore.amazon...ar01-20?&node=4 if you want a quick reference -- buy two, they're small!).

 

Per other suggestions, I formatted it on my PC (FAT, allocation unit size 32K, volume label "NetD-01", not quick-formatted).

 

I have the following simple code, taken from what appears to be several successful C# SD writing examples:

 

Try

   Using SW As New System.IO.StreamWriter("\SD\Test.txt")

       SW.WriteLine("This is a test!")

   End Using

Catch ex as Exception

   Debug.Print("Error writing to SD card: " & ex.Message)

End Try

 

THIS WORKS!  I removed the SD card, put it in my PC, and that file is present and readable!  You'll note that the Date Modified is not accurate unless you have something to set your Netduino's clock.

 

Note: At first I tried the StreamWriter to write simply to "Test.txt", but this threw an error.  Apparently you MUST include the full path.

 

I hope this helps anyone