Anyone tried to use Compact Flash in an embedded system?

[AliPentland]

I am working on a battery operated instrument where I want to store medium ammounts of data and download it later to a PC. I thought Compact Flash would be an ideal solution for the memory storage area, but I'm not running an operating system like DOS or Windows on my instrument which it seems to need. Will I have to write 'drivers' for my instrument to access the Compact Flash?

It looks to me as if Compact Flash is too complex for an embedded design like mine, any one got any experience / advice? Or thoughts on mass storage for embedded systems?

 

[cbarn24050]

how much data do you need to store

 

[AliPentland]

At the moment we are only storing relatively small amounts of data - a few 100k. We've done this in the past with battery backed RAM, and its worked fine.

I guess you are thinking why change to Compact Flash?
We would like to use Compact Flash as it could be swapped between instruments quickly, downloaded to the PC with a 'reader', be compatible with other instruments etc.

If you have any other ideas for storage or advice fire away, I'd be glad to hear them. I'd looking for a better solution.

Thanks, Ali

 

[IRstuff]

According to the Compact Flash specification:

http://www.compactflash.org/cfspc1_4.pdf

the CF interface supports PC-ATA and PC-IDE electrical interfaces, which means that your circuitry needs to drive 50-odd signals correctly, so you will definitely need to build a software or hardware driver for the interface. I've seen it done, so it's not impossible.

As for complexity, if you had a windows-based board, it would be relatively easy to drive the interface. The converse is that a custom design would not be readily readable on a PC, thus requiring dedicated and custom reader hardware/software.

TTFN

 

[nbucska]

Do you have the CF spec's ? What is your processor ?
Is the project cost sensitive ?
<nbucska@pcperipherals.com>

 

[Chancy99]

Check out Jesper Hansen's Yampp7 mp3 player. It uses an AVR Mega128 with a CF interface, among other cool features.

http://www.myplace.nu/mp3/index2.htm

Few other CF projects I know about :

Another mp3 player, a little simpler.

http://www.stanford.edu/class/ee281/projects/aut2001/mp3player/

Nice dev kit for PIC

http://www.armanet.com/Pages/engineeringright.html

Circuit Cellar article and project

http://www.chipcenter.com/circuitcellar/february01/c0201ms1.htm

Dean.

 

[raivo]

There are many memory cards in the market and if is not essential to use Compact Flash then other cards are better. Compact flash needs costly connectors and you must drive tens of pins.

SmartMedia has less than twenty pins and is much easyer to interface. MMC (MultiMediCard) can be read and writen through 3 wire synchronous serial interface found on most microcontrollers. Also there are Sony's Memory Stick and SD (Secure Digital) Cards. I do not know much about last two but theese too may be worth of considering.

 

[cbarn24050]

Hi, the december edition of elektor electronics has an article showing how to interface cf to a 89s8252 micro.

http://www.elektor-electronics.co.uk

 

[47gandalf]

I've used compact flash as system component just as you are. And for many of the same reasons.

We did have to write drivers for one use we made of it. In another place we had a Windows-like embedded OS to interface with it. Still needed drivers, but the vendor had already written and qualified them.

I think that the headaches now will prove to have been worth it. In the near future such memories will be the way to go and you'll already have developed expertise in using them.

 

[m3]

AliPentland,

Compact Flash no need special driver to run in DOS or Windows. This memory card have a built in microcontroller and just add this in IDE port of CPU board.
I have trouble when use a CF for Boot, some CF not run. The better is Sandisk and Danelec.

Regards,

M3