Maker Pro
Maker Pro

Use USB memory stick as random memory?

B

Bill Bowden

Jan 1, 1970
0
Is it possible to use a little USB flash drive as RAM memory for a PIC
microcontroller project without a lot of serial I/O software?

How complicated is it?

What procedure is needed to read and write a single byte to some
location inside the USB flash drive?

I'm guessing it requires writing and reading entire files to move
small bits of data.

-Bill
 
N

Nicholas Sherlock

Jan 1, 1970
0
Bill said:
Is it possible to use a little USB flash drive as RAM memory for a PIC
microcontroller project without a lot of serial I/O software?

How complicated is it?

What procedure is needed to read and write a single byte to some
location inside the USB flash drive?

I'm guessing it requires writing and reading entire files to move
small bits of data.

The drive doesn't know anything about files. You read and write blocks
of data to locations on the flash. You have to implement USB host and
issue USB commands over the wire, which is pretty painful. Why do you
want to use a USB flash drive? You might be better off with, say, an SD
card, which has a far simpler interface designed for small devices to
implement.

Cheers,
Nicholas Sherlock
 
R

Rich Webb

Jan 1, 1970
0
Is it possible to use a little USB flash drive as RAM memory for a PIC
microcontroller project without a lot of serial I/O software?
Nope.

How complicated is it?

Fairly. You'd need to implement a "USB host" to talk to the USB flash
drive. Depending on which side of the build/buy equation you're on, you
can get pre-packaged interface libraries.
What procedure is needed to read and write a single byte to some
location inside the USB flash drive?

I'm guessing it requires writing and reading entire files to move
small bits of data.

If you have to have a USB drive (customer requirement, etc.) then you
do. But, if you just want a ton of flash storage, then it's probably
easier to implement an SPI driver for SD cards in MMC mode.

Here's a link to a PIC project that does just that
http://www.captain.at/electronics/pic-mmc/
 
B

Bob Monsen

Jan 1, 1970
0
Bill Bowden said:
Is it possible to use a little USB flash drive as RAM memory for a PIC
microcontroller project without a lot of serial I/O software?

How complicated is it?

What procedure is needed to read and write a single byte to some
location inside the USB flash drive?

I'm guessing it requires writing and reading entire files to move
small bits of data.

-Bill


If you want to use SD, you might use this:

http://www.futurlec.com/Mini_SC.shtml

It is a 'miniboard' from those Australian guys. You can use it to read and
write an SD card. It is basically just a breakout board, but you won't have
to run your own board.

Regards,
Bob Monsen
 
D

Don McKenzie

Jan 1, 1970
0
Bill said:
Is it possible to use a little USB flash drive as RAM memory for a PIC
microcontroller project without a lot of serial I/O software?

How complicated is it?

What procedure is needed to read and write a single byte to some
location inside the USB flash drive?

I'm guessing it requires writing and reading entire files to move
small bits of data.

1)
http://www.dontronics-shop.com/4d-udrive-usd-g1-tiny-disk-drive-data-storage-module.html

2)
http://www.dontronics-shop.com/ftdi-vdrive2.html

Cheers Don...



--
Don McKenzie

Site Map: http://www.dontronics.com/sitemap
E-Mail Contact Page: http://www.dontronics.com/email

Xbee Wireless Modules, and low cost Interface Boards.
http://www.dontronics-shop.com/xbee-boards.html
 
Top