STM32 BluePill SD Card Reader

Most MM/SD Cards support connection via SPI (How to Use MMC/SDC by ChaN). In this way it is possible to connect a SD Card to BluePill and use it as an external memory storage, but also present it via Mass Storage Class as an USB Card Reader. Bear in mind that the read/write speed is relatively very low.

Using on STM32 BluePill

In STM32CubeIDE

File -> Open Project from File System... -> Directory -> Finish

Connect MMC/SDC to SPI pins

   |¯¯¯¯¯¯¯¯¯\_/¯¯¯¯¯\                  +--------------+
   |                  \                 |              |
   |                CS |-2-----------18-| PB0          |
   |              MOSI |-3-----------17-| PA7          |
   |               VCC |-4--------+3.3V-| 3.3V out     |
   |              SCLK |-5-----------15-| PA5          |
   |               GND |-6----------GND-| GND          |
   |              MISO |-7-----------16-| PA6          |
   |___________________|                |              |
               SD Card                  |     USB      |
                                        +--------------+
                                         BluePill

• fatfs lib by ChaN: R/W access to MMC from the BluePill side
• mmc lib by Internet: low level access to MMC in SPI Mode
• usb-fs lib with MSC: R/W access to MMC from PC side via BluePill's USB

The .ioc file

The .ioc file is just for reference. Do not use 'Generate Code'.