USB host MSC example

Stephan Scherer · ‎2012-01-03

Posted on January 03, 2012 at 09:29

Hi everybody,

i work with the evalboard STM3220G with the USB example from the USB host-device lib.

I try to write additional data in the create/existing file, but I'm not successful.

Can anyone say me, what i must chance to solve that problem?

rosarium · ‎2012-01-03

Posted on January 03, 2012 at 11:20

hi stephan,

if you want to write additional data the created file, you want to take care of certain things.

in the file ''usbh_usr.c'' line no. 623,

//------------------------------------------

/* Write buffer to file */

file_write(&file, 50, textFileBuffer);

//----------------------------------------

Here you have to change the file size from 50 to your desired value.

Also you have to add the required data inside the textFileBuffer.

Stephan Scherer · ‎2012-01-03

Posted on January 03, 2012 at 11:46

Thx for your reply pila,

but maybe you understand me wrong, i don't want to write the data at once.

I want to make something like a data logging.

I have to open the existing file and add some new data.

rosarium · ‎2012-01-03

Posted on January 03, 2012 at 12:19

ok..got it.

presently such option is not there in the example.

But I think it can be implemented by playing a bit with file system.

you can use the function ''file_setpos'' from file.c in EFSL.

Let me know if it helps????

Stephan Scherer · ‎2012-01-03

Posted on January 03, 2012 at 12:46

I can't find either such a file nor this function....

Maybe we er talking about two different examples??

I download the USB Host and Device library (UM1021) from the ST-page.

rosarium · ‎2012-01-03

Posted on January 03, 2012 at 13:20

You are dealing with USB host example or device example??

Stephan Scherer · ‎2012-01-03

Posted on January 03, 2012 at 13:27

Host example for MSC

rosarium · ‎2012-01-03

Posted on January 04, 2012 at 07:34

OK.. So EFSL is not there in your example. FAT_FS is there.

Lemme chk then wht options are there to append a file in FAT_FS.

There should be some in ff.c.

Stephan Scherer · ‎2012-01-05

Posted on January 05, 2012 at 11:50

Thx for your hint pila,

i try to modify it, but it's my first USB-project an di'm a bit confused...

Can u give me some details??

rosarium · ‎2012-01-05

Posted on January 06, 2012 at 06:15

Can u plz let me know what exactly you modified???