Standalone-device to erase USB-stick. ?

worktech

.

I wonder if this is possible:

I like to have a "blackbox" with a USB receptacle.
when you stick a USB-stick in it and press a button
then the "blackbox will erase the USB-stick.

That´s all....however:

a)

The "blackbox" should be very small
and operate from a small battery (1 or 2 button cells ?)

c)

It will not consume power until a push-button is pressed
(batt is connected and·uP controlled (FET) switch·takes over the·power)


d)

A confirmation off the erasure-process taking place would be handy
something like a beep when started and a few beeps when erasure is finished.

c)

Erasure should be secure so no data can be reconstructed from the USB-stick
instead of only erasing (overwriting) there could be 2 actions to make the erasure more secure:
1st all bits are set to 1 or 0 ...after that·the stick is filled with (semi) random bits.


Question 1

---

Is it possible to have something like that using a PIC or other uP ?


Question 2

---

Is it possible to have a good conformation to see if the USB-stick was
really erased...maybe by first writing a few bits to it...and then at the end of
the process trying to read them...if cant be read erasure was succesfull· ?

Question 3

---

How long would it take to erase for example a 10GB stick ? (1 go...only erase)
How long would it take to erase for example a 10GB stick ? (erase and then overwrite with random)
The goal·is as fast as possible.


If above works...i consider to have both USB-stick and erasure-circuit in 1 housing
i would then have a fast (standalone) erasable USB-stick that does not need a PC
to do the erasing...since the USB-stick will also be used to plug into a PC...the erasure
circuit should nor interfere with normal operation.
In this case the whole unit needs to be really small as possible and operate from a small as possible battery.


I do electronics but i´m not a programmer ...and might need someone to make·above for me.

Anyone ...suggestions ...ideas ?


Thanks !

worktech

RickB

AVRs have been used to make standalone usb hosts using a software bitbang method, and this could be used as the basis for what you want. Search AVR Freaks and Google for references. I suspect that an sx-48 could also be used. This would be a non-trivial (expensive) project. And last, the Vinculum USB Host chip sold by Parallax could be used. The code to do your specific task would need to be written.

Rick

worktech

.

Thanks Rick,

I had no idea that it would be difficult (as in expensive· )

I thought there was enough choice of Microchip PIC´s that have USB-interfaces
and can act as a host.
·····················
Why not use one of those ?

I thought it would not be so difficult to have a uP spit out similar data as a PC would do
when it is erasing/writing bits to a USB-peripheral...is it that difficult to emulate such a protocol ?

Anyway if there´s anyone...let me know if you could program something like that
and what it takes to have you do that.

Greetings

worktech

RickB

The author of the MyUSB project in the Academy forum of avr freaks might be willing to take it on.

Rick

worktech

.

Tnx Rick,

On mentioned forum...he already replied to my posting.

By the way...very little respons to this thread here...maybe the wrong area ?
On another subject i got much more response...any suggestions ?

Greetz

worktech

Mike Green

I think the issue is that you're asking about a BIG project. It's a lot of work to create a USB master for a mass storage device. Most of the devices with built-in USB controllers have slave controllers. They're designed to plug into a PC or similar bus master.

I think another piece at first read is that you don't seem to have done your homework. For example, your question about erase time shows that you seem to have no idea of the bus speed of USB or what might be involved (time-wise) in the kind of secure erasure you're talking about. Similarly, wanting to use a couple of small coin cells may not be practical. Writing is the most time and power intensive operation you can do with a USB memory stick. Once you figure out how long a secure erasure would take, check the range of power supply drain for typical USB memory sticks. I think you'll find that you'll need a larger battery.

I don't mean to be critical, but you did ask. Think about other postings. Typically, there'll be a lot of response for situations where the person asking seems to have done their homework, asks a clear question, and includes enough supporting information. Other situations might be where there's a teacher and students involved and they're clearly trying very hard, but seem to be lost or too inexperienced somehow and maybe some straightforward advice and guidance is enough to get them going.

RickB

Download the code for Deans project and you will see the complexity involved. There are VERY few USB master projects to be
found on the web. There is a reason for it.
If you only need a few of these, some used laptops might be a bargain.

Rick

Post Edited (RickB) : 5/4/2008 8:45:18 PM GMT

FireHopper

what about using the usb datalogger from parallax for this? wouldn't this possibly help in this?

worktech

.



Thanks FireHopper,

Yes thats an idea...adding a·PIC or other uP with the right software·might do it.

"The Memory Stick Datalogger is a USB host bridge which allows you to connect a USB mass storage device, such as a thumb drive, to your BASIC Stamp, SX or Propeller Microcontroller" :
<!-- m -->http://tinyurl.com/5z6nk8<!-- m -->


Here´s more·stuff to get some more insight :

Vinculum...VNC1L USB Host Controller-chip (the chip on above board)
handles all low-level stuff and USB-protocols.
all you do is connect your uP to it (SPI) wich will tell the vinculum what to do.
<!-- m -->http://www.vinculum.com/<!-- m -->

Vinculum have a similar board
<!-- m -->http://www.vinculum.com/products.html<!-- m -->

Access flashdrives with a microcontroller:
<!-- m -->http://www.lvr.com/access_flash_drives_ ... roller.htm<!-- m -->

USBwhiz-chip manufacturer(used in above article)
<!-- m -->http://www.ghielectronics.com/<!-- m -->

USB Flash-drive (USB-Stick..description at Wikipedia):
<!-- m -->http://en.wikipedia.org/wiki/USB_flash_drive<!-- m -->

Flash-memory (the memory-chips at Wikipedia)
<!-- m -->http://en.wikipedia.org/wiki/Flash_memory<!-- m -->

Resources for Developers of USB Devices in the
Mass Storage Device Class:
<!-- m -->http://www.lvr.com/mass_storage.htm<!-- m -->

Mass Storage Class Firmware using Microchip PIC18F4550
<!-- m -->http://www.microchip.com/stellent/idcpl ... m=en024412<!-- m -->

Dontronics (Australia) selling Vinculum-chip
and related stuff:
<!-- m -->http://www.dontronics-shop.com/USB-Host-p-1-c-380.html<!-- m -->

Host USB implementation using PIC (full doc)
<!-- m -->http://g.fondeville.free.fr/usb_host_en.html<!-- m -->

Maxim, USB On-The-Go basics (usb-host):
<!-- m -->http://www.maxim-ic.com/appnotes.cfm/ap ... umber/1822<!-- m -->

Maxim, MAX3421 USB-controller Host/peripheral
"USB Controllers use a simple 3 or 4-wire SPI
interface to allow any microprocessor, DSP, or ASIC
to become a USB peripheral or USB host."
Similar to the vinculum, handles all the difficult
low-level stuff, USB-protocols...uP speed no problemo:
<!-- m -->http://www.maxim-ic.com/products/interf ... ollers.cfm<!-- m -->


Well that was yesterday´s homework...what say ?
I guess the hardware is solved..make your choice
...my non-educated guess:

Vinculum and a uP of your choice should do it.


This is about as much as i can do and understand

Now who is going to do this for me ? ·

By the way i´m in The Netherlands
if you are there too..then that would be great
allthough for this project distance would not be
such a big problem since you could pretty much do
the whole thing at your own location.

Contact me if you are interested.

Thanks again.

worktech