https://devzone.nordicsemi.com/f/nordic-q-a/14637/about-i2s-data-nrf52832Now we use the SDK V11 I2S sample program to collect data of digital microphone. We want to get the frequency of the sound and the dB value size.I don&#39;t know how to calculate these values.Can you provide some help? Best regards!en-USTelligent Community 13Thu, 23 Jun 2016 07:47:53 GMThttps://devzone.nordicsemi.com/thread/55863?ContentTypeID=1Thu, 23 Jun 2016 07:47:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:920ef697-f1dd-4620-ae81-37982112f7e0Anders Strand<p>Hi.</p> <p>As i2s is a data transfer bus, it does not tell us anything about how the data is structured. You must investigate how your microphone sends the data. Maybe it is simply the sound amplitude at a given time, or maybe it is encoded.</p> <p>When you have receiver the data in the nRF end, you can apply a fast fourier transform <a href="https://en.wikipedia.org/wiki/Fast_Fourier_transform">(fft)</a> to see which frequencies dominate the sound.</p> <p>I am not sure about the volume, but <a href="http://stackoverflow.com/questions/13247904/sound-volume-on-defined-frequency-c">this</a> and <a href="http://stackoverflow.com/questions/2445756/how-can-i-calculate-audio-db-level">this</a> thread should give you some clues.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/55862?ContentTypeID=1Tue, 21 Jun 2016 13:30:27 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6f508180-a425-4e64-9a81-9e817a3253baTOM123<p>yes. Now this problem more troublesome, hope to get your help! Thanks!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/55861?ContentTypeID=1Tue, 21 Jun 2016 09:14:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:93ef50aa-1a18-4976-9261-294303f0ea2dAnders Strand<p>Did you solve your other problem posted <a href="https://devzone.nordicsemi.com/question/84196/about-i2s-data-acquisition-and-processing/">here</a>?</p><div style="clear:both;"></div>