Writing to SD Card with MSP430G2231

See my answer in the other SD card thread for your exact same question.

Hi Jens,

by now I managed to initialize the SD card with ACMD41.

To wait a bit longer for the reponse I added a delay_cycles function.

//Send one byte via SPI
unsigned short spiSendByte(const unsigned short data)
{
  while (SPITXREADY ==0);    // wait while not ready for TX
  SPI_SEND(data);            // write
  while (SPIRXREADY ==0);    // wait for RX buffer (full)
  __delay_cycles(1500);
  return (SPIRXBUF);
}

The SPIRXREADY I found out is set to 1 by a define and never unset so the code would never wait for

the buffer to be full I guess.

So when I send CMD0 and let it run I get 0x01.

Then I send CMD55 and wait for the reponse and then send ACMD41 and wait for the response.

This is going on until the card reponds with 0x00 what it does after sending the CMD55, ACMD41

sequence the second time.

So the mos recent success is that the card initializes now correctly and I even don´t have to single

step through the code.

But I still can`t write anything to the card. The commands for setting blocklength and writing are

responded correct but the data isn´t on the card when I look at it in my hex editor.

Ok so if I use the SDWriteBlock like this :

SDWriteBlock(512ul,512ul,buffer);

It should write to sector one shouldn´t it ??

Now I formated the card with FAT16. My OS is Windows 7.

Do you have a guess at which offset I can expect the data I wanted to write??

It should be one sector full of ones.

MaxE

It should write to sector one shouldn´t it ??

Yes

MaxE

Now I formated the card with FAT16. My OS is Windows 7.

Which has most likely overwritten Sector 1 and maybe reset the whole card content to 0xff except the root directory and the media descriptior parts.

Better first format the card, then write to a sector that's definitely in the data area. (don't ask me where. It's been a while since I looked at disk sectors for unerasing data)

Jens-Michael Gross

Better first format the card, then write to a sector that's definitely in the data area. (don't ask me where. It's been a while since I looked at disk sectors for unerasing data)

Sorry that I told this a bit confusingly but I actually formated the SD Card before I wrote to it.

Now I analyzed the whole procedure with a logic analyzer and everything seems to work correct.

Even I read out the CSD register after the transaction as told by the specs and there are no errors.

So I guess the data is successfully written to the card. Now the only problem is to find it !!

Yiiiiiiiiihaaaaaaaaa,

it works.

Just experimented a lot with the adressoffset and wrote 1000 sectors on the card.

Now I found my data.

Many thanks to you Jens and to Mark Green. You guys gave me such a strong support in the

last few weeks and guided me to success.

MaxE

it works.

Congratulations!

MaxE

Now I found my data.

Where? Onthe card, I suppose, but at which 'windows-filtered storage device' sector? I mean: where did you write it on the MSP and where did it appear under windows?

I wrote beginning in sector 500 up to sector 1500 and it appeared on the card under windows

beginning at sector 265. The next thing to do is to implement some functions to write to the fat16

so when I read out the fat16 boot record maybe I can make more of a guess about

the adressoffset.

Wow. 235 sectors offset. I wonder what Windows stores in these sectors.
Or did the hex editor access 'clusters' rather than raw sectors? Then of course this offset contains the FAT.

There are one or two free FAT file system available for the MSP430. All they need are the low-level functions that read and write a sector - which you now have.
The links are somewhere her ein the forum (I don't remember - I downlaoded the code but lsot the link)