We've got a project built against NNDK 2.6 with a Nano target, and some (but not all) f_open() calls to read and write are returning NULL when they shouldn't. This is a port of a project built against NNDK 2.5.3/MOD5234, and those same calls work as expected. I believe we're calling f_enterFS() and f_chdrive() for each task correctly. I can provide more specifics if anyone is interested, and is there any way to get any extended error information when f_open() fails?
On a possibly-related note, the release notes for NNDK 2.6.1 mention this:
* EFFS
* Fixed mutex bug that generated problems when simultaneous SD cards are used on MOD5441X
We don't think that applies to our project, since we're using only one SD card and the NANO54415 - but it sounds like it could be related. The problem is we're close to releasing the Nano-based product and migrating to a new NNDK now is a significant risk for us.
Thank you
f_open() fails in NNDK 2.6
Re: f_open() fails in NNDK 2.6
Even if you don't plan to update, I would download the latest revision or take a look at the rev history. I think you have to log into your support account to do this. The SPI interface is completely different for the 54415 processors, they refer to it as dspi. So I would definitely run the examples specific to the nano first as a test.