Final Code : MMC SD Card interfacing

Final Code : MMC SD Card interfacing


►Final Code

Using these functions, along with Chan’s tff.c module creates all the tools you need to read and write to a FAT16 SD card. An example program to display the root directory of the SD card would look like this:

CODE:

#include "integer.h"
#include "tff.h"
#include "diskio.h"

FATFS SDCard;

void ShowDirectory( char *path );
char *ShowFatTime( WORD ThisTime );
char *ShowFatDate( WORD ThisDate );
DWORD get_fattime();

void main()
{
   /* 1) mount drive... */
   if( f_mount( 0, &SDCard ) )
   {
      printf("Couldn't mount drive...\r\n");
      while( 1 );
   }

   /* 2) initialize card... */
   if( disk_initialize( 0 ) & STA_NOINIT )
   {
      switch( CardType )
      {
         case 0 :
            printf("Couldn't find SD card\r\n");
            break;
         case 1 :
            printf("Card type is MMC - Can't use this type\r\n");
            break;
         case 2 :
            printf("Couldn't initialize SD Card drive...\r\n");
            break;
         default :
            printf("Unknown Card Type error...\r\n");
            break;
      }
      while( 1 );
   }

   /* 3) show directory... */
   ShowDirectory("");

   while( 1 );
}

void ShowDirectory( char *path )
{
   FILINFO finfo;
   DIR dirs;
   FATFS *fs;
   DWORD clust;
   ULONG TotalSpace, FreeSpace;
   FRESULT res;
   char VolumeLabel[12];

   if(disk_read(0, SDCard.win, SDCard.dirbase, 1) != RES_OK)
   {
      printf("\r\nCouldn't read directory sector...\r\n");
      return;
   }

   strncpy( VolumeLabel, &SDCard.win, 11 );
   VolumeLabel[ 11 ] = 0x00;
   if( f_opendir(&dirs, path) == FR_OK )
   {
      if( VolumeLabel[0] == ' ' )
         printf("\r\n Volume in Drive C has no label.\r\n");
      else
         printf("\r\n Volume in Drive C %s\r\n", VolumeLabel );
      printf(" Directory of C:\%s\r\n\n", path );
      while( (f_readdir(&dirs, &finfo) == FR_OK) && finfo.fname[0] )
      {
         putchar('[');
         putchar(( finfo.fattrib & AM_RDO ) ? 'r' : '.');
         putchar(( finfo.fattrib & AM_HID ) ? 'h' : '.');
         putchar(( finfo.fattrib & AM_SYS ) ? 's' : '.');
         putchar(( finfo.fattrib & AM_VOL ) ? 'v' : '.');
         putchar(( finfo.fattrib & AM_LFN ) ? 'l' : '.');
         putchar(( finfo.fattrib & AM_DIR ) ? 'd' : '.');
         putchar(( finfo.fattrib & AM_ARC ) ? 'a' : '.');
         putchar(']');

         printf(" %s  %s   ",
            ShowFatDate(finfo.fdate), ShowFatTime( finfo.ftime ));
         printf("%s %6ld %s\r\n", (finfo.fattrib & AM_DIR)?"<DIR>":"     ",
            finfo.fsize, finfo.fname );
      }
   }
   else
   {
      printf("The system cannot find the path specified.\r\n");
      return;
   }

   printf("%cCalculating disk space...\r", 0x09 );

   // Get free clusters
   res = f_getfree("", &clust, &fs);
   if( res )
   {
      printf("
f_getfree() failed...\r\n");
      return;
   }

   TotalSpace = (DWORD)(fs->max_clust - 2) * fs->csize / 2;
   FreeSpace = clust * fs->csize / 2;
   printf("%c%lu KB total disk space.\r\n", 0x09, TotalSpace );
   printf("%c%lu KB available on the disk.\r\n", 0x09, FreeSpace );
}

char *ShowFatTime( WORD ThisTime )
{
   char msg[12];
   BYTE AM = 1;

   int Hour, Minute, Second;

   Hour = ThisTime >> 11;        // bits 15 through 11 hold Hour...
   Minute = ThisTime & 0x07E0;   // bits 10 through 5 hold Minute... 0000 0111 1110 0000
   Minute = Minute >> 5;
   Second = ThisTime & 0x001F;   //bits 4 through 0 hold Second...   0000 0000 0001 1111
 
   if( Hour > 11 )
   {
      AM = 0;
      if( Hour > 12 )
         Hour -= 12;
   }
   
   sprintf( msg, "%02d:%02d:%02d %s", Hour, Minute, Second*2,
         (AM)?"AM":"PM");
   return( msg );
}


char *ShowFatDate( WORD ThisDate )
{
   char msg[10];

   int Year, Month, Day;

   Year = ThisDate >> 9;         // bits 15 through 9 hold year...
   Month = ThisDate & 0x01E0;    // bits 8 through 5 hold month... 0000 0001 1110 0000
   Month = Month >> 5;
   Day = ThisDate & 0x001F;      //bits 4 through 0 hold day...    0000 0000 0001 1111
   sprintf( msg, "%02d/%02d/%02d", Month, Day, Year-20);
   return( msg );
}

DWORD get_fattime()
{
   RTC_CURRENT rtc;
   RTC_read( &rtc );
 
   return         ((DWORD)((WORD)(rtc.Year) + 20) << 25)
                  | ((DWORD)rtc.Month << 21)
                  | ((DWORD)rtc.Date << 16)
                  | ((DWORD)rtc.Hours << 11)
                  | ((DWORD)rtc.Minutes << 5)
                  | ((DWORD)rtc.Seconds >> 1);
}