4.4 SD Card Disk I/O Layer for AVR

The disk I/O layer code for AVR used in this application note (diskio_avr.c) is a modified version of a sample file available from elm-chan.org/fsw/ff/pfsample.zip. The SD card settings described above are included in the initialization routine. The hash defines for SPI pins and the functions for SPI initialization, transmit, and receive may be reviewed for use with a device other than the tinyAVR 1-series and modified if necessary. Use of the Petitfs library is demonstrated in the 'init_sd_card()' and 'send_buffer()' functions in the main file.