SDMMC FATFS

[samuel_l]

Hi ST Community,

I'm facing an issue with FatFs on SDMMC where f_open() or even f_mount() returns FR_DISK_ERR, even though the SD card is initializing correctly at the HAL level.

Here's a summary of the problem and what I’ve verified so far.

• HAL_SD_Init() completes successfully
• Card information is read correctly:
  • CID
  • CSD
  • RCA
  • Capacity (LogBlockNbr, LogBlockSize)
• SDMMC interface appears operational
• Raw HAL read/write tests (CID/CSD) work fine

I would be grateful if ST experts or anyone familiar with SDMMC + FatFs integration please help me to resolve this issue :

[Saket_Om]

Hello @samuel_l 

Please refer to the example FatFs_uSD_Standalone on STM32CubeH7.

[Andrei Chichak]

I expect that the SDCard/eMMC chip is new and does not have a file system on it yet. I.E. it needs to be formatted.