STM32duino STM32SD

Enables reading and writing on SD card using SD card slot of the STM32 Board.

storage, data
platformio lib install 1810


STM32 SD library for Arduino

With an STM32 board with SD card slot availability, this library enables reading and writing on SD card using SD card slot of a STM32 board (NUCLEO, DISCOVERY, ...).

This library follow Arduino API.

For more information about it, please visit:


This library is based on FatFs, a generic FAT file system module for small embedded systems.

The FatFs has been ported as Arduino library here. The STM32SD library depends on it.



The FatFs has several user defined options, which is specified from within the ffconf.h file.

This library provides a default user defined options file named ffconf_default.h.

User can provide his own defined options by adding his configuration in a file named ffconf_custom.h at sketch level or in variant folder.


Some default definitions can be overridden using:

SD configurations

  • SD_INSTANCE: some STM32 can have 2 SD peripherals SDMMC1 and SDMMC2, note that this library can managed only one peripheral

    • SDMMC1 (default)
    • SDMMC2
  • SD_HW_FLOW_CTRL: specifies whether the SDMMC hardware flow control is enabled or disabled

    • SD_HW_FLOW_CTRL_DISABLE (default)
  • SD_BUS_WIDE: specifies the SDMMC bus width

    • SD_BUS_WIDE_1B
    • SD_BUS_WIDE_4B (default)
    • SD_BUS_WIDE_8B

SD Transceiver

  • SD_TRANSCEIVER_MODE: specifies whether external Transceiver is enabled or disabled. Available only on some STM32

  • SD_TRANSCEIVER_EN pin number to enable the level shifter

  • SD_TRANSCEIVER_SEL pin number for voltage selection

SD detect and timeout

  • SD_DETECT_PIN pin number

  • SD_DATATIMEOUT constant for Read/Write block