Function FS Read Sector
Loads currently selected sector of file into sector buffer.
Zero on success, error code on failure.
Accesses the SD card. The function attempts a retry, so if you receive an error from it, you may assume that the card became inaccessible.
The error codes returned by this function:
- 1: Card is not initialized
- 2: CMD17 failed
- 3: Timed out during waiting for data token
- 4: CRC error (data is loaded, but possibly corrupt)