Help: ICE_KEYS_EMT

Envelope Measure and Track

Envelope Measure and Track.  This computes an N-length exponetial average of the M-length block maximum
of the magnitude of the high byte of the input samples.  This is an estimate of the current loading of
signal from 0 to 128.  A vaule of 75 to 100 is reasonable loading for an A2D in most environments.