AVR-DOS SDHC cards unreliable?

Jerry · Joined: 25 May 2004 Posts: 40 Location: New York

Testing with Bascom-AVR Version 2.0.7.6. I have read all posts listed in AVR-DOS forum section and still fumbling around to resolve my problem.
Hi all,
I have been using Niclas Fat-Free SD library and Atmega2561 with 14.745 MHz clock for a while with no problems regardless of card type, card size or card speed, 2GB SD up to 16GB SDXC.
I thought I might like to try AVR-DOS since many additional features are available. My hardware remains the same so I know the interface is good. However, Driveinit() seems very inconsistent sometimes gives no error sometimes error. If I get error and perform Drivereset() and then Driveinit() card will then function without issue, sometimes just doing driveinit() a couple times will work. For some reason it seems very picky regarding the card I use. I have 4 Kingston 4GB SDHC class 4 cards and none of them will initialize with AVR-DOS, however they work fine with FAT-Free. I also have 2 8GB Adata SDHC cards and they almost always work with AVR-DOS. Almost is not really good enough.

What I have done in the past when using FAT-Free, since SD cards vary from different manufacturers is to start initialize hardware SPI at highest speed setting then reduce speed setting using SPSR and SPCR registers along with SPIINIT until initialize is good, then I leave it while using the card for reading and writing data. I have tried doing similar with AVR-DOS and regardless of SPI settings Driveinit() gives mixed and inconsistent results.

Another thing I noticed is when using Disksize() it takes about 1 to 2 seconds to return a value. What could be the reason for that?

I would really like to make use of AVR-DOS and would purchase commercial license if I could get reliable and consistent results from it.
Any comments or ideas on the possible problem would be greatly appreciated.

albertsm · Joined: 09 Apr 2004 Posts: 5915 Location: Holland

i yet need to find the first card that does not work. when using AVR-DOS it is important to know that AVR-DOS is the disk operating system library. It works perfect.
But it works together with driver libraries. you can have a driver for XRAM so you can simulate all the AVR-DOS commands, or you can have a driver for a hard disk , CE drive or memory card.
There are different memory card drivers. When using SDHC cards you need to use the proper driver MMCSD_HC.LIB
The lib is written by Josef, the author of AVR-DOS. I altered the lib so it works with MMC cards too. And it was updated for Xmega. One of the updates in 2076 was to get the driver working for some arduino shields. Some shields use the CS pin to control a buffer enable line which is not a good idea since the card is clocked without CS made low. So in 2077 i made that an option. I advise to get the lib from 2077 and test it.
It is also very important that SPI and pins are properly enabled in the bas file that sets up the driver. I think you can always use the highest possible SPI speed for most modern cards.

Jerry · Joined: 25 May 2004 Posts: 40 Location: New York

Hi Mark, thank you for the quick reply.
I verified correct port pins defined in Config_MMCSD_HC.bas it is using $lib "MMCSD_HC.LIB"
I'll download the latest and give it a go.
Kind Regards,
Jerry

Jerry · Joined: 25 May 2004 Posts: 40 Location: New York

OK found the problem. It was in fact hardware.
Thanks for the help.
Jerry

nisse · Joined: 14 Dec 2006 Posts: 50

Jerry, I have a similar issue, could you share what HW problem you found?

Jerry · Joined: 25 May 2004 Posts: 40 Location: New York