83 replies to this topic

[Chris Walker]

Hi msgersch, Netduino Plus will automatically mount SD cards. Just look for the "\SD" folder once you insert the card. Welcome to the Netduino community, Chris

[Edward]

I tried the v4.2 firmware briefly. Had big problems working with SD card (256MB) on the Plus. Seemed like it would only work with files in the root directory. Trying to access anything in a sub-directory (eg, GetFiles) would throw a NotSupported exception. Same code working fine in the 4.1 beta so rolled back to that for now.

[Stefan]

I tried the v4.2 firmware briefly. Had big problems working with SD card (256MB) on the Plus. Seemed like it would only work with files in the root directory.
Trying to access anything in a sub-directory (eg, GetFiles) would throw a NotSupported exception. Same code working fine in the 4.1 beta so rolled back to that for now.

Hi Edward,

That's interesting. Could you provide me with the brand of the SD-card, the filesystem (FAT16/FAT32), the clustersize (512/1024/etc.) and the full path name of the subdirectory you try to read from (ex.: \SD\Foldername\)?
I'll try to reproduce it tonight. It could be a problem with the filesystem or unsupported characters in the path or something.

[Stefan]

So far I can't reproduce it. I use firmware "Netduino Plus (v4.2.0.0 b1) by Secret Labs LLC" (BuildDate: Jun 8 2011)

This is my working code:

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.IO;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;
using SecretLabs.NETMF.IO;

namespace Folder_Bug_test
{
    public class Program
    {
        public static void Main()
        {
            // Created a test folder
            Directory.CreateDirectory("SD\\Test");

            // Creates 10 text files
            for (int FileNo = 0; FileNo < 10; ++FileNo)
            {
                FileStream test = new FileStream("SD\\Test\\File " + FileNo.ToString() + ".txt", FileMode.CreateNew);
                test.Write(new byte[] { 0x54, 0x45, 0x53, 0x54 }, 0, 4);
                test.Close();
            }

            // Creates 10 subfolders
            for (int DirNo = 0; DirNo < 10; ++DirNo)
            {
                Directory.CreateDirectory("SD\\Test\\Subfolder " + DirNo.ToString());
            }

            // Reads all filenames
            string[] Files = Directory.GetFiles("SD\\Test");
            for (int FileNo = 0; FileNo < Files.Length; ++FileNo)
            {
                Debug.Print("Found file: " + Files[FileNo]);
            }

            // Reads all directories
            string[] Directories = Directory.GetDirectories("SD\\Test");
            for (int DirNo = 0; DirNo < Directories.Length; ++DirNo)
            {
                Debug.Print("Found directory: " + Directories[DirNo]);
            }
        }

    }
}

This is the output:

Found file: \SD\Test\File 0.txt
Found file: \SD\Test\File 1.txt
Found file: \SD\Test\File 2.txt
Found file: \SD\Test\File 3.txt
Found file: \SD\Test\File 4.txt
Found file: \SD\Test\File 5.txt
Found file: \SD\Test\File 6.txt
Found file: \SD\Test\File 7.txt
Found file: \SD\Test\File 8.txt
Found file: \SD\Test\File 9.txt
Found directory: \SD\Test\Subfolder 0
Found directory: \SD\Test\Subfolder 1
Found directory: \SD\Test\Subfolder 2
Found directory: \SD\Test\Subfolder 3
Found directory: \SD\Test\Subfolder 4
Found directory: \SD\Test\Subfolder 5
Found directory: \SD\Test\Subfolder 6
Found directory: \SD\Test\Subfolder 7
Found directory: \SD\Test\Subfolder 8
Found directory: \SD\Test\Subfolder 9

[Edward]

Thanks for trying to replicate. I'll install the firmware here again and retry.. Card is a 128MB SanDisk (dug out from the back of a dusty drawer, came with an old phone) Formatted as FAT32/2048 by Win7 - files were written by Win7. Path \\SD\www.

[Stefan]

Thanks for trying to replicate.
I'll install the firmware here again and retry..

Hi Edward,

If your code fails to run, could you please provide us (a portion of) your code?

[Edward]

I reinstlled everything, reflashed everything and reformatted the card. And all is working fine now. Thanks for taking the time to run those tests it gave me the confidence to give 4.2 another try. Hopefully my next feedback will be more worthwhile!

[Edward]

Spoke to soon. The problem seems to be a power cycling one. If the netduino is powered up with the card in the slot then the exception is thrown. If I take the card out and re-insert it with the power kept on then the progtam will run. So is the problem that the card isn't being mounted at power on only on insertion?

[Stefan]

Interesting. So to reproduce it, I need to execute the following steps: - Insert the µSD-card into the Netduino Plus - Put power the Netduino Plus - Execute the program I posted in this thread earlier Then it will fail, am I right? If so, I'm going to try it out tonight! By the way, remember, beta software can always contain a few flaws, it's a risk using Beta firmware. appairently you found a flaw

[Stefan]

Interesting. So to reproduce it, I need to execute the following steps:

Nope, can't reproduce it that way. Is it possible you can mention the exact steps and perhaps (a part of) the source code to reproduce it?

[Edward]

The code is:

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.IO;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;
using SecretLabs.NETMF.IO;

namespace SD_Card_test
{
    public class Program
    {
        public static void Main()
        {
           var fs= Directory.GetFiles(@"SD");
        }

    }
}

and the exception is:
A first chance exception of type 'System.NotSupportedException' occurred in Microsoft.SPOT.IO.dll
An unhandled exception of type 'System.NotSupportedException' occurred in Microsoft.SPOT.IO.dll

By the way, remember, beta software can always contain a few flaws, it's a risk using Beta firmware.
appairently you found a flaw

yup - trying to help find them and fix them!

[mikepo]

Now, reading that it does not work on power-on, but works afterwards, maybe it's a timing/initialization issue for the SD card. Especially since you mentioned it's an older card. How about putting some delay in the code before trying to read the files? Like Thread.Sleep or some delay loop. Giving the card time to initialize. If the timing issue is in the firmware itself mounting the card, this will not help, but it's worth a try. Also, not sure if you have tied that already, but reproducing it with another card might pinpoint ifit's a netduino issue or card compatibility, HTH, Mike

[Chris Walker]

Hi Edward,

           var fs= Directory.GetFiles(@"SD");

What happens if you use the full path?

fs = Directory.GetFiles(@"\SD");

Chris

[Stefan]

Can't reproduce it still, but I thought of something which could be the case. Just to be sure. If you go to your project properties, and go to .NET Micro Framework, to which device are you deploying?

[Edward]

Thanks all for the various helpful suggestions but no change for any of them. I'm awaiting delivery of some 2GB cards to compare results against. Will update again as soon as I get my hands on them.

[Edward]

My 2GB SD cards arrived but only hours before going on vacation. A quick test suggested that they do >not< exhibit the access problems described abover for the 128MB card. One question; clarification about what is in and what in not included in the 4.2 B1 release - is the tuning down of buffer sizes and counts for SD card FAT file access to alleviate memory allocation problems included in this firmware?

[Chris Walker]

One question; clarification about what is in and what in not included in the 4.2 B1 release - is the tuning down of buffer sizes and counts for SD card FAT file access to alleviate memory allocation problems included in this firmware?

We build the tuning down of buffer sizes into the v4.1.0.0 firmware, and it's now included in the v4.2 firmware as well.

What is the FAT file access count memory issue? If that has been changed in the 4.2 codebase, it's included as well.

The GC bugfixes are included for sure.

We'll be posting v4.2 beta 2 later this weekend, now with "WithEvents" support for VB programmers.

Chris

[grimbouk]

hi guys,

should "EndOfStream" for StreamReader be working at the momment?

The following code always returns "True" and never drops into the loop to read data

StreamReader sr = new StreamReader("SD\\Filename.txt");
while (!sr.EndOfStream)
{
    string line = sr.ReadLine();
}
sr.Close()

any ideas?

thanks
Tim

[Chris Walker]

Hi Tim, Could you please attach the file? [Also, silly question...is the file empty?] Chris

[grimbouk]

Hi Chris,

Hi Tim,

Could you please attach the file? [Also, silly question...is the file empty?]

Chris

sure. I'm actually writing the file in a previous session using streamwriter. The file looks fine, I can open it by taking the SD card and putting it in an addapter on my PC. I haven't checked yet if the lines are terminated correctly though.

Here's some sample code:-

            string filename = "SD\\test.txt";
            StreamWriter sw = new StreamWriter(filename);
            for (int i = 0; i < 5; i++ )
            {
                sw.WriteLine("TestLine" + i.ToString());
            }
            sw.Flush();
            sw.Close();

            Debug.Print(File.Exists(filename) ? "File Found" : "File Not Found!");

            StreamReader sr = new StreamReader(filename);
            while (!sr.EndOfStream)
            {
                string line = sr.ReadLine();
                Debug.Print(line);
            }
            sr.Close();

When I run the code I get the "FileFound" output, but nothing is returned for reading the lines. Any ideas what I'm doing wrong?

I've attached the file that's created as well.

thanks
Tim

Update: If I skip the check for !sr.EndOfStream, and just do a ReadLine, I do just get the first line of data. At least this proves that reading data works and that each line of data seems terminated correctly. It does just seem that EndOfStream is not working... or I'm misusing it ;-)

Attached Files

•  test.txt   55bytes   4 downloads