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研发客服导语"fatfs是一个小型的文件系统，在小型的嵌入式系统中使用非常的广泛，STM32CubeMx自带该文件系统，我们通过简单的配置就能够使用，将前面的SD卡的读写操作进行修改，将文件系统挂载到SD卡进行操作，通过简单的文件创建、打开、写入、读取、关闭来演示如果使用Fatfs。"
第一节 系统要求
•软件
STM32CubeMX
•硬件
野火指南者开发板，SD卡
第二节 CubeMX配置
本节使用SDIO接口与SD卡连接，利用DMA模式读写SD卡，将FATFS文件系统挂载SD卡中。
1.SDIO配置
1.DMA配置
2.中断配置
3.Fatfs 文件系统的配置
Fatfs配置中我们选在支持中文文件名。选在SD Card,设置为logical drivers 为1.
按照上述配置后点击代码生成。
第三节 MDK 代码编写
使用MDK打开项目，在bspdriversd.c 中修改代码,并包含头文件#include "sdio.h"。
在BSPSDReadBlocks() 函数中修改，使用前面编写好的SDIO DMA读写的函数进行SD卡的读写，Fatfs文件系统将会在SDRead() 和SDWrite()调用该函数。
/* USER CODE END BeforeReadBlocksSection */
/**
* @brief Reads block(s) from a specified address in an SD card, in polling mode.
* @param pData: Pointer to the buffer that will contain the data to transmit
* @param ReadAddr: Address from where data is to be read
* @param NumOfBlocks: Number of SD blocks to read
* @param Timeout: Timeout for read operation
* @retval SD status
*/
__weak uint8_t BSP_SD_ReadBlocks(uint32_t *pData, uint32_t ReadAddr, uint32_t NumOfBlocks, uint32_t Timeout)
{
uint8_t sd_state = MSD_OK;
if (SDIO_ReadBlocks_DMA(&hsd, (uint8_t*)pData,ReadAddr,NumOfBlocks) != HAL_OK)
{
sd_state = MSD_ERROR;
}
return sd_state;
}
/* USER CODE BEGIN BeforeWriteBlocksSection */
/* can be used to modify previous code / undefine following code / add code */
/* USER CODE END BeforeWriteBlocksSection */
/**
* @brief Writes block(s) to a specified address in an SD card, in polling mode.
* @param pData: Pointer to the buffer that will contain the data to transmit
* @param WriteAddr: Address from where data is to be written
* @param NumOfBlocks: Number of SD blocks to write
* @param Timeout: Timeout for write operation
* @retval SD status
*/
__weak uint8_t BSP_SD_WriteBlocks(uint32_t *pData, uint32_t WriteAddr, uint32_t NumOfBlocks, uint32_t Timeout)
{
uint8_t sd_state = MSD_OK;
if (SDIO_WriteBlocks_DMA(&hsd, (uint8_t*)pData,WriteAddr,NumOfBlocks) != HAL_OK)
{
sd_state = MSD_ERROR;
}
return sd_state;
}
直接修改SD的读写函数，在内部使用DMA模式。也可以在sddiskio.c 中修改SDread 和SD_Write 但是发现这个文件是只读模式，所以就不修改了。：
/**
* @brief Reads Sector(s)
* @param lun : not used
* @param *buff: Data buffer to store read data
* @param sector: Sector address (LBA)
* @param count: Number of sectors to read (1..128)
* @retval DRESULT: Operation result
*/
DRESULT SD_read(BYTE lun, BYTE *buff, DWORD sector, UINT count)
{
DRESULT res = RES_ERROR;
uint32_t timeout = 100000;
if(BSP_SD_ReadBlocks((uint32_t*)buff,
(uint32_t) (sector),
count, SD_DATATIMEOUT) == MSD_OK)
{
while(BSP_SD_GetCardState()!= MSD_OK)
{
if (timeout-- == 0)
{
return RES_ERROR;
}
}
res = RES_OK;
}
return res;
}
/**
* @brief Writes Sector(s)
* @param lun : not used
* @param *buff: Data to be written
* @param sector: Sector address (LBA)
* @param count: Number of sectors to write (1..128)
* @retval DRESULT: Operation result
*/
#if _USE_WRITE == 1
DRESULT SD_write(BYTE lun, const BYTE *buff, DWORD sector, UINT count)
{
DRESULT res = RES_ERROR;
uint32_t timeout = 100000;
if(BSP_SD_WriteBlocks((uint32_t*)buff,
(uint32_t)(sector),
count, SD_DATATIMEOUT) == MSD_OK)
{
while(BSP_SD_GetCardState()!= MSD_OK)
{
if (timeout-- == 0)
{
return RES_ERROR;
}
}
res = RES_OK;
}
return res;
}
#endif /* _USE_WRITE == 1 */
编译下载进行测试：
第四节效果演示
我们可以看见文件读写测试能够正常使用。