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
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
-----------------
-----------------
Nope.
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.
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
-- Rich Webb Norfolk, VA
Whatever you do, it'll be dog slow compared to real RAM.
Do you want this for non volatile storage? I'd go with the suggestions to use an SD card, or if your storage requirements are modest an 8-pin serial EEPROM.
-- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html
If you want to use SD, you might use this:
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
1)
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
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.