(contributors: Tom Flock, John Boxall, Elijah Gregory)
Added: post-processing functions limitLeft/Right/Band() to limit the amount output changes between readings
Sparkfun Spectrum Shield Driver v0.9 (contributors: Tom Flock, John Boxall, Elijah Gregory)
Written using Arduino IDE v1.0.5 and Processing v2.0.3 on Nov 3rd, 2013. by Tom Flock
Based on Example 48.1 - tronixstuff.com/tutorials > chapter 48 - 30 Jan 2013 by John Boxall
Running stats computations added June 25th, 2014 by Elijah J. Gregory
Limiter functions added July 14th, 2014; limit the amount output signal may increase or decrease
between samples (hard limit on derivative of output signal).
This code receives multiplexed data from the Spectrum Shield's two MSGEQ7 ICs
and transmits the values via serial at a 115200 baud rate.
The fourteen values are seperated by commas and are terminated by a newline,
which is the format your visualization code should expect.
Currently the driver computes the running average, variance, and standard deviation for each
input band. Upon initialization the mean is computed assuming zero input volume. This mean is
used to baseline correct later values. The driver outputs the average values to create smooth
visualization input. The standard deviation is used to detect changes in the process generating
the input data and will be used to detect visualization start/stop times.