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I tried to add a string to a text file saved in "microSD" using "f_write" of "FATFS", but the writte
Hello everyone in the community.
■What you are having trouble with :
→I tried to add a string to a text file saved in "microSD" using "f_write" of "FATFS", but the written content was not saved.
■Specific phenomenon:
→As shown in the PG below, the result of "f_write" is "FR_OK", and "byteswritten" also returns the number of written bytes, but no data is obtained even if "f_read" is performed.
When I checked the contents of the SD card, the written contents were not saved.
*The contents of the SD card were checked by stopping debugging after "f_close" processing.
*See PG below
*When I checked the contents of the file separately using only f_read, I was able to read it.
■Environment:
・Windows
・STM32CubeIDE_1.12.1
・nucleo-f207zgt6
・C language
■PG
static const char* filename = "test.txt";
FATFS sDFatFs;
FIL myFile;
if (f_mount(&sDFatFs, "", 0) != FR_OK){
return;
}
if(f_open(&myFile, filename, FA_OPEN_ALWAYS | FA_WRITE | FA_READ) != FR_OK){
return;
}
uint32_t byteswritten, bytesread;
FRESULT res;
uint8_t wtext[] = "This is STM32 working with FatFs\r\n";
uint8_t rtext[100];
f_lseek(&myFile, f_size(&myFile));
res = f_write(&myFile, wtext, sizeof(wtext), (void *)&byteswritten);
f_printf(&myFile, wtext);
if((byteswritten == 0) || (res != FR_OK)) {
f_close(&myFile);
return;
}
f_sync(&myFile);
f_lseek(&myFile, 0);
f_read(&myFile, rtext, sizeof(rtext), (void *)&bytesread);
f_close(&myFile);
■SDIO
