Description
The purpose of STEVAL-MKI138V1 is to provide a demonstration of decoding and streaming of digital MEMS microphone outputs. The STEVAL-MKI138V1 demonstration board hosts the MP34DT01 (top-port digital microphone), working as a sensor and the STM32F107RC microcontroller, which functions as an audio decoder. These microphones are analog-to-digital transducers. They are capable of sensing sound pressure and converting it to a digital signal using the PDM technique. The STM32 microcontroller decodes the PDM signals from the microphones and streams the audio via USB. The STEVAL-MKI138V1 is a sound card automatically recognized by the PC as an audio device. Connection is made through a USB cable, which both powers the board and streams the audio collected from the microphones to the PC. It is also possible to use the STEVAL-MKI138V1 as an interface board for other microphone boards (STEVAL-MKI126Vx), in which case use of the APWorkbench software tool is recommended. Top view Bottom view

Features
■ Powered and connected to PC through USB
■ Sound card automatically recognized by the PC as an audio device.
■ MEMS microphones provide a high frequency data stream (1 to 3.25 MHz) of 1 bit digital samples (PDM technique)
■ Audio collected from the microphones is sent to the PC through USB
■ LED status indicator
■ RoHS compliant