USB Sticks write error

[ivosenn]

Hello

I'm using MQX4.1 with the  TWR-K60D100M and Keil IDE. I'm using the mfs and USB host of the MQX to write data to an USB Stick. I modified the example of the mfs_usb in the shell.c that every 400ms the string: "2014-05-14;13:59:45;2,4979e+01;\n" is added to a file on the stick. With older sticks sized up to about 8GB everithing works fine. Also with a bigger newer one 128GB Verbatim 49064 everything is ok. With the Stick from Kingston DT101 G2 and a Verbatim SSD with 256GB both formated as FAT32, the writing works for a few minutes. The writing of this few bytes takes about 500ms to 1s on this Sticks, which I think is very long. After a few minutes of logging the writes doesn' work anymore and I get a write timeout. On the USB I can see that a data out Package is repeated many times and the Stick always gives a NAK. Does anybody know similar problems or does anybody know a solution?

Regards Ivo 

Original Attachment has been moved to: Shell_Task.c.txt.zip

[soledad]

Hi,

“USB MQX examples are based on the MSD specification; however, several USB sticks manufacturers don’t meet the specification (timing, endpoint handling, supported commands etc). Thus, when a USB stick is out of specification, the embedded file-system libraries are unable to support all the variations such as non-embedded RTOS, OS or stack/library do (like Mac-OS or MS Windows). So, it may be required adding a considerable amount of code in order to support all the variations.

MQX developers are continuously improving the MSD Host applications, testing more USB sticks for every release and applying workarounds if necessary. However, a universal workaround for this is not possible because of the big variety of non-compliant USB sticks on the market. We are very sorry for any inconveniences this may cause.”

Have a great day,
Regards
Sol
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