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Sd card corruption



We are seeing ocasionall sd card corruption on some units deployed in the field.
The hardware is EM module and the sd card is a mini sd card Verbatim 2GB.
The corruption manifests as a lot of files and folders with random names (letters and numbers) being created out of the blue.
When you load the sd card in a windows PC and try to open the files is doesn’t. If you try to delete a folder or file, they won’t get deleted.
The only solution is to format the sd card again.
Is there anything that we can do to add robustness in the app as far as the sd card r/w is concerned?
I believe we are doing everything as supposed: mount, dismount, closing files, etc.

Last week on a particular unit the garbage files and folders look like pieces of code.
As I couldn’t copy the file structure I did a print screen which I’m attaching.
Maybe you guys can make sense out of it.



What is your firmware version? Please try latest SDK.


Hi Mike,

  • Let me clarify that the sd card is not removed.
    It is placed there during production, it is closed inside the product enclosure not accessible from outside. It is only removed by support people if necessary.

  • The latest SDK firmware is loaded on the units.

  • We are using perfectly common code with StreamWriter and StreamReader. Flushing and closing files after use. We are not able to reproduce this behaviour. And I can’t tell that is occurring at [italic]that [/italic]particular part of the code.

  • I can confirm that the hardware is the same on all machines: EM module and the SD cards are also the same brand and production lot. But note that the sd card corruption does not occur on all units, just a few.

  • Looking like code is what make it more strange. This is the first time we notice the resemblance with code. The usual corruption is a bunch of letters and numbers making random files and folder names. I would guess that something is going into some buffer that gets dumped to the sd card at some point.


Please send us an email with link to this post at ghielec at
We will try to send you a test firmware that might solve a possible issue.


I have found this issue as well. It turned out to be my SD card. I switched to a new card and it worked just fine.

Were you trying to read/write web files to the card when this happened? The fragments on the drive look like Javascript.