Tuesday, October 14, 2014

Measure audio level using Root Mean Square on Spark Core

A Spark.io library to retrive RMS and Spl value from an audio input.


This library reads data from an ADC pin and returns the RMS value of the input simply using RMS avarage.
The root mean square (abbreviated RMS or rms), also known as the quadratic mean, is a statistical measure of the magnitude of a varying quantity.
Here is simply implemented by getting samples, for each of them making the root, then the mean for all the collected samples, and finally square the result.

This library is a derivation of the work you can find here: http://davidegironi.blogspot.it/2013/05/avr-atmega-audio-input-root-mean-square.html
So for more information about RMS, you can read the post above.


Code

Notes
  • read risk disclaimer
  • excuse my bad english