使用FATFS文件系统读写SD卡

定义相关变量

/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/
#include "stdio.h"
FATFS fs;                 // Work area (file system object) for logical drive
FIL fil;                  // file objects
 
uint32_t byteswritten;                /* File write counts */
uint32_t bytesread;                   /* File read counts */
uint8_t wtext[] = "This is STM32 working with FatFs"; /* File write buffer */
uint8_t rtext[100];                     /* File read buffers */
char filename[] = "STM32cube.txt";
/* USER CODE END PV */

进行读写

/* USER CODE BEGIN 2 */
    printf("
 ****** FatFs Example ******

");
 
    /*##-1- Register the file system object to the FatFs module ##############*/
    retSD = f_mount(&fs, "", 0);
    if(retSD)
    {
        printf(" mount error : %d 
",retSD);
        Error_Handler();
    }
    else
        printf(" mount sucess!!! 
");
     
    /*##-2- Create and Open new text file objects with write access ######*/
    retSD = f_open(&fil, filename, FA_CREATE_ALWAYS | FA_WRITE);
    if(retSD)
        printf(" open file error : %d
",retSD);
    else
        printf(" open file sucess!!! 
");
     
    /*##-3- Write data to the text files ###############################*/
    retSD = f_write(&fil, wtext, sizeof(wtext), (void *)&byteswritten);
    if(retSD)
        printf(" write file error : %d
",retSD);
    else
    {
        printf(" write file sucess!!! 
");
        printf(" write Data : %s
",wtext);
    }
     
    /*##-4- Close the open text files ################################*/
    retSD = f_close(&fil);
    if(retSD)
        printf(" close error : %d
",retSD);
    else
        printf(" close sucess!!! 
");
     
    /*##-5- Open the text files object with read access ##############*/
    retSD = f_open(&fil, filename, FA_READ);
    if(retSD)
        printf(" open file error : %d
",retSD);
    else
        printf(" open file sucess!!! 
");
     
    /*##-6- Read data from the text files ##########################*/
    retSD = f_read(&fil, rtext, sizeof(rtext), (UINT*)&bytesread);
    if(retSD)
        printf(" read error!!! %d
",retSD);
    else
    {
        printf(" read sucess!!! 
");
        printf(" read Data : %s
",rtext);
    }
     
    /*##-7- Close the open text files ############################*/
    retSD = f_close(&fil);
    if(retSD)  
        printf(" close error!!! %d
",retSD);
    else
        printf(" close sucess!!! 
");
     
    /*##-8- Compare read data with the expected data ############*/
    if(bytesread == byteswritten)
    { 
        printf(" FatFs is working well!!!
");
    }
  /* USER CODE END 2 */

完整的代码工程链接：https://pan.baidu.com/s/11ptg47VsVxnL_2rfkcFXdg
提取码：tciq