PIC单片机 读/写 MMC/SD 卡的简单小程序

这里介绍一个简单的PIC单片机 读/写 MMC/SD 卡的小程序

// MMC module connections

sbit Mmc_Chip_Select           at LATC0_bit;  // for writing to output pin always use latch (PIC18 family)

sbit Mmc_Chip_Select_Direction at TRISC0_bit;

// eof MMC module connections

const LINE_LEN = 43;

char err_txt[20]       = "FAT16 not found";

char file_contents[LINE_LEN] = "XX MMC/SD FAT16 library by Anton Rieckertn";

char           filename[14] = "MIKRO00x.TXT";          // File names

unsigned short loop, loop2;

unsigned long  i, size;

char           Buffer[512];

// UART1 write text and new line (carriage return + line feed)

void UART1_Write_Line(char *uart_text) {

  UART1_Write_Text(uart_text);

  UART1_Write(13);

  UART1_Write(10);

}

// Creates new file and writes some data to it

void M_Create_New_File() {

  filename[7] = 'A';

  Mmc_Fat_Set_File_Date(2010, 4, 19, 9, 0, 0); // Set file date & time info

  Mmc_Fat_Assign(&filename, 0xA0);          // Find existing file or create a new one

  Mmc_Fat_Rewrite();                        // To clear file and start with new data

  for(loop = 1; loop <= 99; loop++) {

    UART1_Write('.');

    file_contents[0] = loop / 10 + 48;

    file_contents[1] = loop % 10 + 48;

    Mmc_Fat_Write(file_contents, LINE_LEN-1);   // write data to the assigned file

  }

}

// Creates many new files and writes data to them

void M_Create_Multiple_Files() {

  for(loop2 = 'B'; loop2 <= 'Z'; loop2++) {

    UART1_Write(loop2);                  // signal the progress

    filename[7] = loop2;                 // set filename

    Mmc_Fat_Set_File_Date(2010, 4, 19, 9, 0, 0); // Set file date & time info

    Mmc_Fat_Assign(&filename, 0xA0);     // find existing file or create a new one

    Mmc_Fat_Rewrite();                   // To clear file and start with new data

    for(loop = 1; loop <= 44; loop++) {

      file_contents[0] = loop / 10 + 48;

      file_contents[1] = loop % 10 + 48;

      Mmc_Fat_Write(file_contents, LINE_LEN-1);  // write data to the assigned file

    }

  }

}

// Opens an existing file and rewrites it

void M_Open_File_Rewrite() {

  filename[7] = 'C';

  Mmc_Fat_Assign(&filename, 0);

  Mmc_Fat_Rewrite();

  for(loop = 1; loop <= 55; loop++) {

    file_contents[0] = loop / 10 + 48;

    file_contents[1] = loop % 10 + 48;

    Mmc_Fat_Write(file_contents, LINE_LEN-1);    // write data to the assigned file

  }

}

// Opens an existing file and appends data to it

//               (and alters the date/time stamp)

void M_Open_File_Append() {

   filename[7] = 'B';

   Mmc_Fat_Assign(&filename, 0);

   Mmc_Fat_Set_File_Date(2010, 4, 19, 9, 20, 0);

   Mmc_Fat_Append();                                    // Prepare file for append

   Mmc_Fat_Write(" for mikroElektronika 2010n", 27);   // Write data to assigned file

}

// Opens an existing file, reads data from it and puts it to UART

void M_Open_File_Read() {

  char character;

  filename[7] = 'B';

  Mmc_Fat_Assign(&filename, 0);

  Mmc_Fat_Reset(&size);            // To read file, procedure returns size of file

  for (i = 1; i <= size; i++) {

    Mmc_Fat_Read(&character);

    UART1_Write(character);        // Write data to UART

  }

}

// Deletes a file. If file doesn't exist, it will first be created

// and then deleted.

void M_Delete_File() {

  filename[7] = 'F';

  Mmc_Fat_Assign(filename, 0);

  Mmc_Fat_Delete();

}

// Tests whether file exists, and if so sends its creation date

// and file size via UART

void M_Test_File_Exist() {

  unsigned long  fsize;

  unsigned int   year;

  unsigned short month, day, hour, minute;

  unsigned char  outstr[12];

  filename[7] = 'B';       //uncomment this line to search for file that DOES exists

//  filename[7] = 'F';       //uncomment this line to search for file that DOES NOT exist

  if (Mmc_Fat_Assign(filename, 0)) {

    //--- file has been found - get its create date

    Mmc_Fat_Get_File_Date(&year, &month, &day, &hour, &minute);

    UART1_Write_Text(" created: ");

    WordToStr(year, outstr);

    UART1_Write_Text(outstr);

    ByteToStr(month, outstr);

    UART1_Write_Text(outstr);

    WordToStr(day, outstr);

    UART1_Write_Text(outstr);

    WordToStr(hour, outstr);

    UART1_Write_Text(outstr);

    WordToStr(minute, outstr);

    UART1_Write_Text(outstr);

    //--- file has been found - get its modified date

    Mmc_Fat_Get_File_Date_Modified(&year, &month, &day, &hour, &minute);

    UART1_Write_Text(" modified: ");

    WordToStr(year, outstr);

    UART1_Write_Text(outstr);

    ByteToStr(month, outstr);

    UART1_Write_Text(outstr);

    WordToStr(day, outstr);

    UART1_Write_Text(outstr);

    WordToStr(hour, outstr);

    UART1_Write_Text(outstr);

    WordToStr(minute, outstr);

    UART1_Write_Text(outstr);

    //--- get file size

    fsize = Mmc_Fat_Get_File_Size();

    LongToStr((signed long)fsize, outstr);

    UART1_Write_Line(outstr);

  }

  else {

    //--- file was not found - signal it

    UART1_Write(0x55);

    Delay_ms(1000);

    UART1_Write(0x55);

  }

}

// Tries to create a swap file, whose size will be at least 100

// sectors (see Help for details)

void M_Create_Swap_File() {

  unsigned int i;

  for(i=0; i<512; i++)

    Buffer[i] = i;

  size = Mmc_Fat_Get_Swap_File(5000, "mikroE.txt", 0x20);   // see help on this function for details

  if (size) {

    LongToStr((signed long)size, err_txt);

    UART1_Write_Line(err_txt);

    for(i=0; i<5000; i++) {

      Mmc_Write_Sector(size++, Buffer);

      UART1_Write('.');

    }

  }

}

// Main. Uncomment the function(s) to test the desired operation(s)

void main() {

  #define COMPLETE_EXAMPLE         // comment this line to make simpler/smaller example

  ADCON1 |= 0x0F;                  // Configure AN pins as digital

  CMCON  |= 7;                     // Turn off comparators

  // Initialize UART1 module

  UART1_Init(19200);

  Delay_ms(10);

  UART1_Write_Line("PIC-Started"); // PIC present report

  // Initialize SPI1 module

  SPI1_Init_Advanced(_SPI_MASTER_OSC_DIV64, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_LOW, _SPI_LOW_2_HIGH);

  // use fat16 quick format instead of init routine if a formatting is needed

  if (Mmc_Fat_Init() == 0) {

    // reinitialize spi at higher speed

    SPI1_Init_Advanced(_SPI_MASTER_OSC_DIV4, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_LOW, _SPI_LOW_2_HIGH);

    //--- Test start

    UART1_Write_Line("Test Start.");

    //--- Test routines. Uncomment them one-by-one to test certain features

    M_Create_New_File();

    #ifdef COMPLETE_EXAMPLE

      M_Create_Multiple_Files();

      M_Open_File_Rewrite();

      M_Open_File_Append();

      M_Open_File_Read();

      M_Delete_File();

      M_Test_File_Exist();

      M_Create_Swap_File();

    #endif

    UART1_Write_Line("Test End.");

  }

  else {

    UART1_Write_Line(err_txt); // Note: Mmc_Fat_Init tries to initialize a card more than once.

                               //       If card is not present, initialization may last longer (depending on clock speed)

  }

}