3.1 Write Function

The Petit FatFS module contains a write function with some restrictions, in order to minimize the required memory. These restrictions include:

• Files cannot be created; only an existing file can be written to
• Files cannot be expanded in size
• The time stamp of a file cannot be updated
• A write operation will only start and stop on a sector boundary
• A read-only file attribute will not block a write operation

This means that in order to write to a file, it must already exist on the SDC/MMC, and have the required size allocated.