0

MEMS Microphone Breakout - SPW2430
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

MEMS Microphone Breakout - SPW2430

by Sarah2019 on Tue Jul 30, 2019 5:18 pm

Hello,

I want to record sound by "Adafruit Silicon MEMS Microphone Breakout - SPW2430".
Just I tap on the sensor and record the detected signal.
What electronics do I need to use? I have a DC power-supply, oscilloscope, what else do I need?

Thanks for your help at this matter.
Sarah

Sarah2019
 
Posts: 2
Joined: Tue Jul 30, 2019 5:12 pm

Re: MEMS Microphone Breakout - SPW2430

by adafruit_support_mike on Wed Jul 31, 2019 2:17 pm

What kind of recorded output do you want.. raw data, WAV files, or some other audio format?

The hardware you’ll need depends on the result you want.

adafruit_support_mike
 
Posts: 59172
Joined: Thu Feb 11, 2010 2:51 pm

Re: MEMS Microphone Breakout - SPW2430

by Sarah2019 on Wed Jul 31, 2019 4:36 pm

I want just audio, I’ll take FFT of that.

Sarah2019
 
Posts: 2
Joined: Tue Jul 30, 2019 5:12 pm

Re: MEMS Microphone Breakout - SPW2430

by adafruit_support_mike on Fri Aug 02, 2019 12:00 am

If you want to do FFTs, you'll need digitized audio sampled at least twice as fast as the highest frequency of interest.

Doing that by hand with a RasPi is fairly complicated, because Linux is a time-slicing OS. It gives each program about 10ms on a CPU, then suspends it to give the next program a turn. That's okay for human-speed things like typing and using a mouse, but causes significant problems when you get down into the millisecond and microsecond range. Anything that needs real-time stability has to be handled with a kernel module.

You can save a lot of effort by using an I2S mic:

https://www.adafruit.com/product/3421

That does the analog-to-digital conversion internally, and there's already a kernel module to transfer the data to the RasPi.

adafruit_support_mike
 
Posts: 59172
Joined: Thu Feb 11, 2010 2:51 pm

Please be positive and constructive with your questions and comments.