STM32cubeMX配置FreeRTOS-51、USB-U盘读写

1-选USB-FS，Host_Only
2-USB_HOST，Mass Storage Host Class配置为大容量存储设备，调试为3，512个words,即2K字节。
3-FATFS，勾选USB Disk，CODE_PAGE设置Latin1改S-C-(DBCS),LFN为----STACK.
4-工程堆栈全为1000。
5-在main.c文件中 代码0中增加代码
extern ApplicationTypeDef Appli_state;
extern USBH_HandleTypeDef hUsbHostFS;
extern char USBHPath[4]; // USBH logical drive path
 
FATFS FatfsUDisk; // File system object for USB disk logical drive
FIL myFile; // File object
 
static void MSC_Application(void)
{
    FRESULT fres; // FatFs function common result code
    uint32_t byteswrite;
    uint8_t str[] = "hello world!";
 
    /* Register the file system object to the FatFs module */
    if( f_mount(&FatfsUDisk, (TCHAR const*)USBHPath, 0) != FR_OK)
    {
        Error_Handler(); //FatFs Initialization Error
    }
    else
    {
        /* Create and Open a new text file object with write access */
        if(f_open(&myFile, "test.txt", FA_CREATE_ALWAYS | FA_WRITE) != FR_OK)
        {
            Error_Handler(); //'STM32.TXT' file Open for write Error
        }
        else
        {
            fres = f_write(&myFile, str, sizeof(str), (void *)&byteswrite);
            if(byteswrite == 0 || (fres != FR_OK))
            {
                Error_Handler();
            }
            else
            {
                f_close(&myFile); //Close the open text file
            }
        }
    }
}
6-在main.c代码3中中增加
   switch(Appli_state)
    {
        case APPLICATION_READY:
            MSC_Application();
            Appli_state = APPLICATION_DISCONNECT;
            break;
        case APPLICATION_DISCONNECT:
            f_mount(NULL, "", 0);
            break;
        default:
            break;
    }
插上U盘后新建了tast文件内容hello word。