The purpose of the STEVAL-MKI117V2 demonstration board is to provide an example of the decoding and streaming of digital MEMS microphone outputs.
The STEVAL-MKI117V2 demonstration board hosts the MP45DT02 (top-port digital microphone), working as a sensor, and the STM32F107RC microcontroller, working as an audio decoder.
These microphones are analog-to-digital transducers, in other words, they are able to sense sound pressure and convert this signal into a digital signal using the PDM technique.
The STM32 microcontroller decodes the PDM signal coming from the microphones and streams the audio via the USB.
The STEVAL-MKI117V2 demonstration board is a sound card automatically recognized by the PC as an audio device. The connection is made through a USB cable which also supplies the board and then streams the collected audio.