VCC note: Memory Card is a 3.6V device. Connect it to either 3.3V provided by the board or use external 3.6 power supply. Old Arduino uses 5V logic and it is not recommended. It may shorten lifespan ...

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 ...