Chan's FatFS read problem!Hello my friends, I'm really confused about the Chan's FatFS read-function! I'm able to write and do loggings etc... but reading a file greater than 1 kB doesn't work! I can read up to 1 kB (not including 1 kB). The problem is I see only 0 (zero) above 1 kB! My buffer is 2 kB, so it's not the bufferproblem.
Guest
#680423
I am missing two things in your code: disk_initialize () How does it work without this ? f_close() I would try to read 2048 bytes in four 512 byte steps. Only to see if f_read() has a problem reading more than one sector. holger wrote: > I am missing two things in your code: > disk_initialize () How does it work without this ? > f_close() > > I would try to read 2048 bytes in four 512 byte steps. > Only to see if f_read() has a problem reading more than > one sector. Holger, disk_initialize() is done when you call f_open(). f_close? hmmm I thought this was only needed when you write to SD, for flushing the data. But maybe it also works for reading! I'll try that. So f_read() reads only 512 bytes max.?? I thought as long as the buffer can be filled. Thank you. f_read normally has no problems reading more than 512 bytes. But you can easily check how much it really read by looking at ByteRead. f_close() also didn't worked. I managend by looping till the buffer is filled. But what if I want to know how big the file is, so I know when to stop copying to the buffer?
Guest
#680441
>But what if I want to >know how big the file is, so I know when to stop copying to the buffer? Ask FileObject.fsize ? You should compare ByteRead against ByteToRead, not against zero. ReplyPlease log in before posting. |