sdioio uses SDIO high-speed interface to communicate with SD cards, it is not pin compatible with SPI and requires special wiring. Not all chips support SDIO, and if they do, you usually have to use special pins! It also requires CircuitPython 6.0.

The Feather STM32F405 Express uses SDIO to connect its built in micro SD card slot.  Didn't notice it had an SD card slot?  We hid it on the underside.

To mount the SD card, use the following code.  Remember to put it in the file mount_sd.py on CIRCUITPY so you can easily call it from code.py or the REPL with import mount_sd.

import board
import sdioio
import storage

sdcard = sdioio.SDCard(
    clock=board.SDIO_CLOCK,
    command=board.SDIO_COMMAND,
    data=board.SDIO_DATA,
    frequency=25000000)

vfs = storage.VfsFat(sdcard)

storage.mount(vfs, "/sd")
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This guide was first published on Jul 31, 2020. It was last updated on Mar 29, 2023.

This page (Feather STM32F405 Express) was last updated on Jul 24, 2020.

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