how to estimate sound intensity using MEMS Microphone?

[kajetan]

Posted on February 08, 2015 at 19:05

hi,

I've been looking for a way to estimate sound intensity using MEMS microphone for a very long time. I am using STM32F4DISCOVERY board with a MEMS microphone on it (it's MP45DT02). I wrote an application that receives sound using this this microphone, writes it into a buffer and converts it from PDM to PCM using library given by ST. So far it works very similar to a program given by ST - ''Audio playback and record''. Later I use fast fourier transform to get the signal spectrum.I need to estimate how the amplitude of the sound will be reflected on the spectrum's bars height. The datasheets are modest or even say nothing about it. How can I solve the problem?  #mp45dt02-mems-microphone-fourier

[Alessandro MORCELLI]

Posted on April 08, 2015 at 11:29

Hi Sir,

in order to understand the realtion between the digital audio output and the sound intensity i would suggest to read the ST aplication note AN4426 at the MEMS microphone web page:

http://www.st.com/stonline/stappl/resourceSelector/app?page=fullResourceSelector&doctype=application_note&SubClassID=1564

Regards, Alessandro

[jeannot]

Posted on May 12, 2015 at 16:09

hi,

i am new on this page but i need some help. Please im working on STM32F4  and i want now to write an code with the microphono on board. I want to have finally an 16 bit on output(PCM). there is a way to do it? thanks giovani