Building your own flash drive

Where can I find schematics of a USB flash drive. This is the little sticks with a 8 gig or so of flash in them that operate like a plug in hard drive.

I have a need to build one of these into a board I'm making. I don't want to reinvent the wheel if there are reference designs out there.

thanks

Reply to
Mook Johnson
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Don't want to burst your bubble here but unless you plan to build several million systems a year chances are your cost per chip set will be higher than buying the sticks at a computer discount store. Maybe you could crack the shell and place it as a little daughterboard.

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Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Does it have to be USB? There are other memory formats out there.

Reply to
mpm

mpm wrote in news: snipped-for-privacy@o80g2000hse.googlegroups.com:

I wonder if one of the photo mass storage modules would work better than USB flashdrives? Like Compact Flash or SD memory. I suspect that the add-on reader/writers for these are just simple connections to the USB cable. Just add a socket on the PCB.I supose you could solder them in,too.

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Jim Yanik
jyanik
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Reply to
Jim Yanik

The card reader for my camera's flash ROM shows up as a "USB to IDE" interface.

On modern hardware, this card reader is plug-and-play and works much like a thumbdrive. Not too shabby.

Tim

-- Deep Fryer: A very philosophical monk. Website @

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add-on

Reply to
Tim Williams

USB2230

5th Generation Hi-Speed USB Flash Media & IrDA Controller with Integrated Card Power FETs

USB Flash Module

Reply to
Andy

Do you actually need the USB interface or are you just after a bunch of flash memory? An SD card is an often used option in this case.

Dave.

Reply to
David L. Jones

If you're "rolling your own" interface and code, compact flash looks just like an IDE hard drive. A USB memory stick, however, only looks like a hard drive after you get the USB stack and correct protocol all implemented. I.e., much more software to write.

SD cards are a little weird, AFAIK -- they complete interface at the "wire" level is not fully available without NDAs and whatnot, although the SD card readers use an IC that makes the SD card appear, again, as an IDE hard drive on the far side of a USB link. Hence only the guy who made the USBSD interface IC needed to sign all those NDAs...

No, not at all; the interface ICs for SD cards or USB memory sticks are plenty complex.

There are SD cards

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and even CompactFlash cards where they've put that "controller" IC into the memory card into, and thus the SD card can plug directly into a USB port as well (and the CompactFlash card reader really was little more than "wires"), but these are very much the exception rather than the norm. (It never really made sense for CompactFlash cards either, since unlike the SD card shown at the link above you still need the mechanical adapter... the idea originally was apparently that, say, 128MB CF card w/internal USB bridge & mechanical adapter might be, say, $120 whereas a regular 128MB CF card was, say, $100 and a full-fledged reader was $80.)

Indeed -- this is a good idea. It's amazing how cheap flash memory is these days... It was only something like 5 years ago that we were paying something like $10 a 2MB flash IC, and today you can get something around a gigabyte for that much in the form of an SD card or USB memory stick.

---Joel

Reply to
Joel Koltner

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Those are some good thoughts. I need to store a lot of data on a flash disk (of any type) that can be read either by a USB 2.0 link or a wireless USB link. The desire is to have the embedded system write files to the NTFS file system and have a windows notebook just plugin and read the files off at high speed when the job is done. We're talking a full 2 - 8 GB of data so the high speed is needed. The box won't be opened to read the data so just removing the chips isn't an option unfortunately. Also I'd like to solder the chips in so the connector doesn't give problems with age moisture and vibration.

the SD cards look like an interesting option. I was thinking that there were some reference designs by the IC manufacturers that made their USB chip with a flash port on it look like a USB drive. No firmware needed just glue on the chips and away you go. Nothing like this available?

Reply to
Mook Johnson

The AT90USBKEY Atmel demonstration board is a USB flash drive out of the box, source included. It has 16MB of flash on-board for demonstration purposes. Building a USB drive into your product with the chip that's on this board would probably be a cinch!

Cheers, Nicholas Sherlock

Reply to
Nicholas Sherlock

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