FAT32 code for MultiMedia Cards

[Miniman]

Thanks for the driver! I haven't tested it yet.. But I have a few questions:
1. Is it possible to get a list of all the files on the card? well, maby not the whole list at once but a few files to show on a lcd and then scroll?

2. How large cards can it handle? is it 2^32 bytes? 4Gb?

Thanks...

[Tomi]

The answers are simple:
1. Take a look on FindDirEntry() function. This function steps over the entire directory structure to find a file. With minimal modification you can get a directory list (e.g. replace the strcmp() call to a printf() )
2. Theoretically the maximum card size is:
(0x0FFFFFFF sectors) * 512 Bytes/sector = 128 GB (This is the reason why I wrote FAT32 instead of FAT16; the PIC has not enough RAM space to use other than 512Bytes/cluster so the limit is 32MB for FAT16)

[miky]

Hi Tomi,
I am trying to put your code into 18f452 - is there any chance to change
#locate FATTable = 0x0800
#locate gFiles = 0x0A00
#locate gFAT32Vars = 0x0E70
#locate DiskInfo = 0x0E90

so it fits into 18f452 (one open file is enough).

Thanks,
miky

[Tomi]

Hi Miky,
Of course you can relocate the variables. When I started with this code the 18F6720 had some errata especially handling RAM space in the 0x100-0x200 range. In a case of "error-free" PIC you don't need to use #locate directives.

[miky]

Tomi,
the 18f452 ram ends 5FFh. When going from top to bottom (the difference is 900h):
#locate FATTable = 0x0800 -> -100 ??
#locate gFiles = 0x0A00 -> 100h ??
#locate gFAT32Vars = 0x0E70 -> 570h
#locate DiskInfo = 0x0E90 -> 590h

When compiling without #locate than I get an error (not enough ram memory).
So my Q to you - how to arrange the ram space (e.g. for MAXFILES =1)
in order to fit into 5FFh area (as your code is complex)??
Thanks,
Miky

[Tomi]

Hi Miky,
Maybe you have to try 18F4515 (3.9kB RAM) instead of 18F452 (I think 452 has not enough RAM space). I think this chip is pin-compatible with 452.

[miky]

Hi Tomi,
I managed to get compiled the code on 452 (83%mem) by cutting off the #locate. However, the init of the card is now the issue (at least for me..)
I am using SD card 512MB. The init command (after the cmd0, instead of cmd1 you have to apply both) shall be:
result = mmc_send_cmd(MMC_CMD_SEND_OP_APPLSPEC,0,1);
result = mmc_send_cmd(MMC_CMD_SEND_OP_COND41,0,1);
as an example from mmc_spi (it works) or:
c=mmc_cmd(0x77,0x00000000,128,0x00,0x99);
//if (c==0x00) { goto ready;}
c=mmc_cmd(0x69,0x00000000,128,0x00,0x99);
if (c==0x00) { goto ready;}
as an example from mmcdriver.c (also works fine). When modifying your init code to:

char MMCInit()
{
char response,iii,errcnt;

//restart_wdt();
output_high(ChipSel);
output_high(ChipClk);
output_high(ChipDin);
//bit_clear(SSPCON1,5);
//SSPCON1 = 0x32; // modify this number to change SPI clock rate
//SSPSTAT = 0;
iii = 10;
errcnt = 100;
do {
MMCOut(0xFF);
} while (--iii);
delay_us(20000);
output_low(ChipClk);
output_low(ChipSel);
MMCOut(0x40);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x95);
MMC8Clock();
response = MMCIn();
output_high(ChipSel);
output_high(ChipClk);
do {
delay_us(2000);

output_low(ChipClk);
output_low(ChipSel);
MMCOut(0x77);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x01); //01
MMC8Clock();
response = MMCIn();
output_high(ChipSel);
output_high(ChipClk);
//MMC8Clock(); //

//output_low(ChipClk);
output_low(ChipSel);
MMCOut(0x69);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x01); //01
MMC8Clock();
response = MMCIn();
output_high(ChipSel);
output_high(ChipClk);


MMC8Clock();
errcnt--;
} while (response && errcnt);
return errcnt;
}

it does not work (eer=0). I am initialising the SPI by:
SETUP_SPI(SPI_MASTER | SPI_CLK_DIV_64 | SPI_H_TO_L |SPI_XMIT_L_TO_H );

BTW why you toggle the (ChipClk)? Nobody does it in their codes.
Miky
[/code]

[miky]

Tomi,
so this is what I would say shall work (but does not):

char MMCInit()
{
char response,iii,errcnt;

//restart_wdt();
output_high(ChipSel);
//output_high(ChipClk);
//output_high(ChipDin);
//bit_clear(SSPCON1,5);
//SSPCON1 = 0x32; // modify this number to change SPI clock rate
//SSPSTAT = 0;
iii = 10;
errcnt = 100;
do {
MMCOut(0xFF);
} while (--iii);
delay_us(20000);
//output_low(ChipClk);
output_low(ChipSel);
MMCOut(0x40);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x95);
MMC8Clock();
response = MMCIn();
output_high(ChipSel);
//output_high(ChipClk);
do {
delay_us(2000);

//output_low(ChipClk);
output_low(ChipSel);
MMCOut(0x77);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x01); //01, ff, 95 ??
MMC8Clock();
response = MMCIn();
output_high(ChipSel);
//output_high(ChipClk);
//MMC8Clock(); //

//output_low(ChipClk);
output_low(ChipSel);
MMCOut(0x69);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x00);
MMCOut(0x01); //01, ff, 95 ??
MMC8Clock();
response = MMCIn();
output_high(ChipSel);
//output_high(ChipClk);


// ??? MMC8Clock();
errcnt--;
} while (response && errcnt);
return errcnt;
}

[miky]

Tomi,
I've fixed the SD init, so no it initialise the SD. However, I see some strange thing in this example(using 18f452, Maxfiles = 1, ram 83% full):


printf("\n\r Start MMC init \n\r");
v = 1;
if (!input(CardInserted)) { // if MMC card is in place
v = MMCInit(); // init the card
delay_ms(50);
crd = input(CardInserted);
printf("\n\rerr =%d Card inserted = %d \n\r",v,crd);
}
if (v != 0) { printf("\n\rerrInit\n\r");goto ERR_EX;}

printf("\n\r Start FAT init \n\r");
InitFAT(); // init the file system

printf("\n\r Start EVENT.LOG \n\r");

strcpy(gfilename,"EVENTS1.LOG");
f = fopen(gfilename,'a'); // open EVENTS1.LOG for append
if (f < MAXFILES) {
sprintf(msg,"%04lu.%02u.%02u. %02u:%02u:%02u ",myrec.tm_year,myrec.tm_mon,myrec.tm_mday,myrec.tm_hour,myrec.tm_min,myrec.tm_sec);
fputstring(msg,f);
strcpy(msg,"System started XXYY001\r\n");
fputstring(msg,f);
fclose(f);
}
printf("\n\r END EVENT.LOG \n\r"); delay_ms(500);
ERR_EX:
printf("\n\r END \n\r");
}

It creates EVENT1.LOG file, but the text in it (I can see it when I open it with Notepad) is coming from other sector (winhex F9000), while the by fputstring written text is at F82000. The card is 512MB, fresh formatted.
What could be wrong?
Miky

[miky]

.. fputstring written text is at [b]F8200[/b]..

[Andreas]

Hi miky !

Could You show us what You have done to get the SD Card initialized ??

best regards
Andreas

[Miniman]

Today I'm going to begin working with this code and the mmc card.
And I got some questions:
1. Is it possible to use software spi instead? (I guess it is, why would it not be?)
2. If so, All I need to change is these three functions

[Miniman]

I have tried this code all day. but it just don't work.. any one have gotten it to work? I do not know what kould be wrong, I have debugged it and I do not find what could be the issue... I'm using a 18F4550 and I have change MAXFILES to 1 and decreased all #loacte's by 0x700 to fit my ram. could that be the problem?
/Mattias

[CGEngineering]

[Miniman]

I have got it to work!!!
Oh man how happy I am!

This is what I have changed(the rest are the same):