X-Nucleo-CCA02M1 is the expansion board compatible with the NUCLEO board for audio applications. Embedded on this board there are two top port digital mics with metal cases (MP34DT01-M). It is possible to house up to six external coupon boards as well as STEVAL-MKI129V1/2/3. This enables the evaluation of different mics in respect to the mics embedded on the expansion board.