SD cards: Copying from one card to another (Eye-Fi video transmission)

FlyingFishFinger

Hi all-
I'm wondering if it's possible to clone a file system without having an MC that can actually handle one. The goal is to send video clips via the Eye-Fi SD card, but as far as it stands, it can only do jpeg images. There's a hack that lets it send video clips by switching the avi file header for a jpeg file header, which seems to fool the Eye-Fi. Now, I have a box that records video to another SD card and takes care of that card's file system (FAT16, I believe).
My question is whether I can copy the contents of the first card at byte-level and write it to the Eye-Fi (which expects an FS). At this point that would be for pure jpeg data.
If it works I'd like to change up the video file header before I write it to the Eye-Fi.
Thanks

Rafael

Mike Green

The Propeller can copy an SD card at the byte level just using absolute card block numbers.

You can also do this under Linux

FlyingFishFinger

I could use the Propeller, yes. Would that retain the FS though?

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You've got to play the game.
You can't win.
You can't break even, except on a very cold day.
It doesn't get that cold.
~Laws of Thermodynamics~

Paul Baker

If you do a byte level move, the whole card it will have an identical fs to the original.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

Ugha

Is this at all possible with a BS2? Or possibly an SX?
Even if it takes 5 minutes per image, it'd be useful [noparse]:)[/noparse]

Mike Green

It's possible, but not practical. The main issue is that blocks are 512 bytes and neither the Stamps nor the SX have the buffer space available for a full block.

Ugha

This is way out of my league but I had a thought.... could you use multiple microprocessors (two SXs? I dunno) to
read the blocks? Request access then have one processor read the first half and another ignore the first half and pickup
on the second... then so on?

If this idea is stupid please forgive me, it was just a thought and like I said, I know very, very little about the subject.

I also apologize for "jacking" this thread.

Mike Green

You can do all sorts of things with microprocessors. For example, you could program an SX to emulate a small I2C RAM (like maybe 250 bytes). This would be an expensive and inefficient way to do it, but you could. You could certainly use multiple SXs to drive a pair of Vinculum chips (on Parallax USB Memory Stick Dataloggers) to copy drives or files, but it would not be a good use of money or intellectual effort. There are much better ways to learn how to program or use an SX microcontroller and much better ways to accomplish the task.

Paul Baker

The Propeller is much more equipped to handle a task such as this, higher processing power and enough memory to buffer things.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.