SDFileSystem.h

00001 /* mbed Microcontroller Library - SDFileSystem
00002  * Copyright (c) 2008-2009, sford
00003  */
00004  
00005 // VERY DRAFT CODE!!! 
00006 
00007 #ifndef SDFILESYSTEM_H
00008 #define SDFILESYSTEM_H
00009 
00010 #include "mbed.h"
00011 #include "FATFileSystem.h"
00012 
00013 /* Class: SDFileSystem
00014  *  Access the filesystem on an SD Card using SPI
00015  *
00016  * Example:
00017  * > SDFileSystem sd(p5, p6, p7, p12, "sd");
00018  * > 
00019  * > int main() {
00020  * >     FILE *fp = fopen("/sd/myfile.txt", "w");
00021  * >     fprintf(fp, "Hello World!\n");
00022  * >     fclose(fp);
00023  * > }
00024  */
00025 class SDFileSystem : public FATFileSystem {
00026 public:
00027 
00028     /* Constructor: SDFileSystem
00029      *  Create the File System for accessing an SD Card using SPI
00030      *
00031      * Variables:
00032      *  mosi - SPI mosi pin connected to SD Card
00033      *  miso - SPI miso pin conencted to SD Card
00034      *  sclk - SPI sclk pin connected to SD Card
00035      *  cs   - DigitalOut pin used as SD Card chip select
00036    *  name - The name used to access the filesystem
00037      */
00038     SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name);
00039     virtual int disk_initialize();
00040     virtual int disk_write(const char *buffer, int block_number);
00041     virtual int disk_read(char *buffer, int block_number);    
00042     virtual int disk_status();
00043     virtual int disk_sync();
00044     virtual int disk_sectors();
00045 
00046 protected:
00047 
00048     int _cmd(int cmd, int arg);
00049     int _cmdx(int cmd, int arg);
00050     int _cmd41();
00051     int _cmd8();
00052     int _cmd58();
00053     int initialise_card();
00054     int initialise_card_v1();
00055     int initialise_card_v2();
00056     
00057     
00058     int _read(char *buffer, int length);
00059     int _write(const char *buffer, int length);
00060     int _sd_sectors();
00061     int _sectors;
00062     
00063     SPI _spi;
00064     DigitalOut _cs; 
00065     
00066     struct CSD_REGISTER  {
00067      unsigned reserved1:4;
00068      unsigned reserved2:3;
00069      unsigned low_voltage:1;
00070      unsigned reserved3:7;
00071      unsigned volt_27_28:1;
00072      unsigned volt_28_29:1;
00073      unsigned volt_29_30:1;
00074      unsigned volt_30_31:1;
00075      unsigned volt_31_32:1;
00076      unsigned volt_32_33:1;
00077      unsigned volt_33_34:1;
00078      unsigned volt_34_35:1;
00079      unsigned volt_35_36:1;
00080      unsigned reserved:6;
00081      unsigned card_capacity_status:1;
00082      unsigned card_power_up_status:1;
00083     };    
00084 };
00085 
00086 #endif