The sound files are uncompressed WAV files (working on adding others) and all are contained in the root directory of a MicroSD card inserted into the AudioBFF. The speaker should be a 3w 4ohm - 8 ohm ...

It would be nice if the SDIO pins were defined for this variant like other variants. A pinout diagram is here. I think this is the correct definition. // SDIO #define PIN_SD_CLK (18u) #define ...