/* Example playing an enveloped noise source
using Mozzi sonification library.
Demonstrates Ead (exponential attack decay).
Circuit: Audio output on digital pin 9 on a Uno or similar, or
DAC/A14 on Teensy 3.1, or
check the README or http://sensorium.github.io/Mozzi/
Mozzi documentation/API
https://sensorium.github.io/Mozzi/doc/html/index.html
Mozzi help/discussion/announcements:
https://groups.google.com/forum/#!forum/mozzi-users
Copyright 2013-2024 Tim Barrass and the Mozzi Team
Mozzi is licensed under the GNU Lesser General Public Licence (LGPL) Version 2.1 or later.
*/
#define MOZZI_CONTROL_RATE 256 // Hz, powers of 2 are most reliable
#include <Mozzi.h>
#include <Oscil.h> // oscillator template
#include <tables/brownnoise8192_int8.h> // recorded audio wavetable
#include <Ead.h> // exponential attack decay
#include <EventDelay.h>
#include <mozzi_rand.h>
Oscil<BROWNNOISE8192_NUM_CELLS, MOZZI_AUDIO_RATE> aNoise(BROWNNOISE8192_DATA);
EventDelay kDelay; // for triggering envelope start
Ead kEnvelope(MOZZI_CONTROL_RATE); // resolution will be MOZZI_CONTROL_RATE
int gain;
void setup(){
// use float to set freq because it will be small and fractional
aNoise.setFreq((float)MOZZI_AUDIO_RATE/BROWNNOISE8192_SAMPLERATE);
randSeed(); // fresh random, MUST be called before startMozzi - wierd bug
startMozzi();
kDelay.start(1000);
}
void updateControl(){
// jump around in audio noise table to disrupt obvious looping
aNoise.setPhase(rand((unsigned int)BROWNNOISE8192_NUM_CELLS));
if(kDelay.ready()){
// set random parameters
unsigned int duration = rand(500u)+200;
unsigned int attack = rand(75)+5; // +5 so the internal step size is more likely to be >0
unsigned int decay = duration - attack;
kEnvelope.start(attack,decay);
kDelay.start(duration+500);
}
gain = (int) kEnvelope.next();
}
AudioOutput updateAudio(){
return MonoOutput::from16Bit(gain*aNoise.next());
}
void loop(){
audioHook(); // required here
}
