Solved
Please help on the filename problem for microSD card
Posted on June 04, 2016 at 01:37
I can't read the first the characters in the first file.
The problem is the encoding of the files are different.
the thing is why the encoding are different. I didn't change anything. Actually I use ANSI in the setting.
My question is
1.
I developed a board using STM32F411 chip with uSD card.The code is generated by cubemx. only add a little bit code in main(). The hardware is OK. I can correctly write a file to sd card. But the weird thing is that the filename accepts 7 chars, not 6 chars. If I use 6 chars in the filename, the character encoding is totally different.
In the testing I only change the filename. I attached two files generated by the chip.
I can't read the first the characters in the first file.
The problem is the encoding of the files are different.
the thing is why the encoding are different. I didn't change anything. Actually I use ANSI in the setting.
My question is
1.
why the program uses two different encodings
for the files
just because I use different filenames
? The file with 7 chars in filename always uses utf-8 encoding.2. how to correctly set the encoding
.Actually in the file I specify it to use ANSI encoding, as in ffconf.h. Why the program uses others?
Please help.The two txt files and the ffconf.h are enclosed as attachment.
int
main(
void
)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration----------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_SDIO_SD_Init();
MX_TIM9_Init();
// MX_FATFS_Init();
MX_USB_DEVICE_Init();
/* USER CODE BEGIN 2 */
/* USER CODE BEGIN WHILE */
FRESULT res;
/* FatFs function common result code */
uint32_t byteswritten, bytesread,byteswrittentotal;
/* File write/read counts */
uint8_t wtext[] =
''testing using own code. This is STM32 working with FatFs..2 ''
;
/* File write buffer . note it will produce a null symbol at the line end*/
uint8_t rtext[100];
char
textbuf[200];
//string buffer
char
filename[]=
''testatxt''
;
//filename can be >8, depends on setting /* File read buffer */
/*##-1- Link the micro SD disk I/O driver ##################################*/
if
(FATFS_LinkDriver(&SD_Driver, SD_Path) == 0)
//SD_Path was defined in fatfs.c by cubemx
{
/*##-2- Register the file system object to the FatFs module ##############*/
if
(f_mount(&SDFatFs, (TCHAR
const
*)SD_Path, 0) != FR_OK)
{
/* FatFs Initialization Error */
Error_Handler();
}
else
{
/* ##-4- Create and Open a new text file object with write access #####*/
if
(f_open(&MyFile, filename, FA_CREATE_ALWAYS | FA_WRITE) != FR_OK)
{
/* 'STMTXT' file Open for write Error */
Error_Handler();
}
else
{
/*##-5- Write data to the text file ################################*/
res = f_write(&MyFile, wtext,
sizeof
(wtext), (
void
*)&byteswritten);
byteswrittentotal=byteswritten;
//write capacity info as testing
BSP_SD_GetCardInfo(&uSdCardInfotmp);
sprintf(textbuf,
''\nThe capacity of the card is:%''
PRIu64
''B\n''
,uSdCardInfotmp.CardCapacity);
//export it to char buffer first. In this way, no null symbol
f_write(&MyFile, textbuf, strlen(textbuf), (
void
*)&byteswritten);
byteswrittentotal+=byteswritten;
sprintf(textbuf,
''\n this is for file: %s \n''
,filename);
//export it to char buffer first. In this way, no null symbol
f_write(&MyFile, textbuf, strlen(textbuf), (
void
*)&byteswritten);
byteswrittentotal+=byteswritten;
if
((byteswritten == 0) || (res != FR_OK))
{
/* 'STMTXT' file Write or EOF Error */
Error_Handler();
}
else
{
/*##-6- Close the open text file #################################*/
f_close(&MyFile);
/*##-7- Open the text file object with read access ###############*/
if
(f_open(&MyFile, filename, FA_READ) != FR_OK)
{
/* 'STMTXT' file Open for read Error */
Error_Handler();
}
else
{
/*##-8- Read data from the text file ###########################*/
res = f_read(&MyFile, rtext,
sizeof
(rtext), (UINT*)&bytesread);
if
((bytesread == 0) || (res != FR_OK))
{
/* 'STMTXT' file Read or EOF Error */
Error_Handler();
}
else
{
/*##-9- Close the open text file #############################*/
f_close(&MyFile);
/*##-10- Compare read data with the expected data ############*/
if
((bytesread != byteswritten))
{
/* Read data is different from the expected data */
Error_Handler();
}
else
{
/* Success of the demo: no error occurrence */
// BSP_LED_On(LED1);
}
}
}
}
}
}
}
/*##-11- Unlink the RAM disk I/O driver ####################################*/
FATFS_UnLinkDriver(SD_Path);