Using the SD card on the
Wunderboard
ECE152

Overview
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What is a file system?
How can I open files?
How do I read and write from files?
What about 'error codes'?
Coding example

What is a file system?
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Memory is just a long list of locations
File systems organize memory
File systems are created based on the memory uint8_t initializeFAT(FATFS* fs)

How can I open files?
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Files are opened for reading or writing
Files can be created, overwritten, or appended to f_open(&log, "/log.txt", FA_WRITE | FA_CREATE_ALWAYS)

How do I write to files?
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You write data as bytes
When writing, tell the function how many bytes
 f_write (FIL*, const void*, UINT, UINT*)
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FIL - File 'handle' const void* - data to be written
UINT - number of bytes to write
UINT* - number of bytes written

What about 'error codes'?
switch (err)
{ case ERR_FMOUNT: sendStringUART("ERROR: Could not mount SD\r\n"); break; case ERR_NODISK: sendStringUART("ERROR: No SDC/MMC present\r\n"); break; case ERR_NOINIT: sendStringUART("ERROR: Unable to initialize FAT.\r\n"); break;
...etc...

Coding example

Things to Remember
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Always double check the error codes
When in doubt, ask questions.