USB MSC buffer size

[froux]

Hi, I'm working on the MSC USB example with the nrf52840-dk.

I'm using only the SD card interface, I've disabled the others.

I've noticed that the interface is quite slow, and it has some problems with large files.

I worked with a similar interface with another mcu (lpc1769) and I found that the buffer size used to read and write the SD is critical. So I've tried to change this value in the example touching the following declaration:

/**
 * @brief Mass storage class work buffer size
 */
#define MSC_WORKBUFFER_SIZE (1024)

I put down something like 1024*16, to have a larger size. But when I do that, the application doesn't start.

What may be the problem in this case? do I have to change something else to have a larger buffer?

thanks a lot!

[Jørgen Holmefjord]

Hi,

I tried to increase the size to 16 *1024 in the unmodified USB MSC example in the SDK, and it does not seem to cause any problems in the application. Did you debug your application to see what causes it to not work? 

Could you share your full project for us to reproduce/debug the problem?

Best regards,
Jørgen