STEVAL-MKI117V1 MEMS microphone demonstration board based on the MP34DT01 and STM32 Data brief Features Powered and connected to PC through USB Sound card automatically recognized by the PC as an audio device The onboard microphones are digital MEMS devices 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 the USB LED status indicator RoHS compliant Description The purpose of the STEVAL-MKI117V1 demonstration board is to provide an example of the decoding and streaming of digital MEMS microphone outputs. The STEVAL-MKI117V1 demonstration board hosts the MP34DT01 (bottom-port digital microphone), working as a sensor, and the STM32F107RC microcontroller, working as an audio decoder. These microphones are analog-to-digital transducers. 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-MKI117V1 demonstration board is a sound card automatically recognized by the PC as an audio device. Connection is made through a USB cable which also supplies the board and then streams the collected audio. March 2012 Doc ID 023000 Rev 1 1/5 For further information contact your local STMicroelectronics sales office. www.st.com 5 Obsolete Product(s) - Obsolete Product(s) & 86 0L %( 86 *1 , , /( , /0 /0 86 *1 ,1 86 / , , 5 86 0, 8 - %( . %( 5 ,1 ,1 / 8 ,1 /( / 9 . B 9 8& 86 4 & 1 4 9, - 9, 8 9 8& 3RZ -5 -3 - -3 67 6B 67 6B -7 -7 8& 5 5 5 8& -7 * Schematics STEVAL-MKI117V1 1 Schematics Figure 1. Schematic diagram (1 of 2) 3 B 5 ( 3 0 8 - 9B& 9B 527&8 5 8&72 9B ) & X B+( (5 & X) ) 60 Q 287 287 5 . 5 728 6 6 3 287 287 - . / 6 0 B , % 1 +1 .&, . 5 ) B 9 & Q 0 B, 5/& & X ) 5 &. 15 67 2&78 67 5 ) 869&&B % & Q 5 & 5 5 % % 0 3 & ( % N 5 N 5 9&B8 5 8&&B9 %6 ) & ( Q 2 2 9% % /% & 5 N 2 2 B9 5 9 &&B6%8 9% QHSL 7% B ,6% & H 6 U XSS O 0 Y 2/5 Doc ID 023000 Rev 1 Obsolete Product(s) - Obsolete Product(s) *1 %<