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Mozzi support
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‎examples/streams-mozzi-a2dp/README.md‎

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# Using Mozzi on Bluetooth
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I am providing a simple integration for [Mozzi](https://sensorium.github.io/Mozzi/). Unfortunatly I needed to make some small changes to make things work together. Those can be found in my [fork](https://github.com/pschatzmann/Mozzi).
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A standard Sketch will need to combine the Audio-Tools with the Mozzi Logic:
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```
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#include "AudioTools.h"
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#include "AudioA2DP.h"
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#include "AudioMozzi.h"
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// Mozzi includes
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// ....
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using namespace audio_tools;
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// Audio Tools
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MozziGenerator mozzi(CONTROL_RATE); // subclass of SoundGenerator
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GeneratedSoundStream<int16_t> in(mozzi, 2); // Stream with 2 channels generated with mozzi
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A2DPStream out = A2DPStream::instance() ; // A2DP input - A2DPStream is a singleton!
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StreamCopy copier(out, in); // copy in to out
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```
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As you can see above you can add the __MozziGenerator__ like any other Generator to the __GeneratedSoundStream__ class.
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In the setup you need to combine the Audio-Tools setup and then call the Mozzi specific setup functions. Replace the __startMozzi()__ with our __GeneratedSoundStream.begin()__:
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```
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void setup(){
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Serial.begin(115200);
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if (mozzi.config().sample_rate!=44100){
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Serial.println("Please set the AUDIO_RATE in the mozzi_config.h to 44100");
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stop();
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}
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// We send the generated sound via A2DP - so we conect to the MyMusic Bluetooth Speaker
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out.begin(TX_MODE, "MyMusic");
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Serial.println("A2DP is connected now...");
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// Add your Mozzi setup here
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// ...
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in.begin();
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}
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```
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Like in any other Mozzi Sketch you need to define the __updateControl()__
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```
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// Mozzi updateControl
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void updateControl(){
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}
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```
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And like in any other Mozzi Sketch you need to define the __updateAudio()__
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```
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// Mozzi updateAudio
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AudioOutput_t updateAudio(){
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}
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```
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In the loop you need to replace the __audioHook()__ with your copy logic:
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```
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// Arduino loop
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void loop() {
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if (out)
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copier.copy();
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}
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```
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That's all to output the generated sound to a Bluetooth Speaker...
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‎examples/streams-mozzi-a2dp/streams-mozzi-a2dp.ino‎

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/**
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* @file streams-generator-a2dp.ino
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* @author Phil Schatzmann
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* @brief see https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/streams-generator-a2dp/README.md
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*
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* @author Phil Schatzmann
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* @copyright GPLv3
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*
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*/
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#include "AudioTools.h"
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#include "AudioA2DP.h"
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#include "AudioMozzi.h"
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#include <Oscil.h>
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#include <tables/cos2048_int8.h> // table for Oscils to play
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#include <mozzi_fixmath.h>
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#include <EventDelay.h>
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#include <mozzi_rand.h>
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#include <mozzi_midi.h>
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using namespace audio_tools;
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typedef int16_t sound_t; // sound will be represented as int16_t (with 2 bytes)
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uint8_t channels = 2; // The stream will have 2 channels
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MozziGenerator mozzi; // subclass of SoundGenerator
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GeneratedSoundStream<sound_t> in(mozzi, channels); // Stream generated with mozzi
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A2DPStream out = A2DPStream::instance() ; // A2DP input - A2DPStream is a singleton!
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StreamCopy copier(out, in); // copy in to out
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/// Copied from AMsynth.ino
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#define CONTROL_RATE 64 // Hz, powers of 2 are most reliable
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// audio oscils
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Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aCarrier(COS2048_DATA);
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Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aModulator(COS2048_DATA);
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Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aModDepth(COS2048_DATA);
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// for scheduling note changes in updateControl()
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EventDelay kNoteChangeDelay;
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// synthesis parameters in fixed point formats
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Q8n8 ratio; // unsigned int with 8 integer bits and 8 fractional bits
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Q24n8 carrier_freq; // unsigned long with 24 integer bits and 8 fractional bits
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Q24n8 mod_freq; // unsigned long with 24 integer bits and 8 fractional bits
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// for random notes
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Q8n0 octave_start_note = 42;
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void setup(){
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Serial.begin(115200);
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if (mozzi.info().sample_rate!=44100){
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Serial.println("Please set the AUDIO_RATE in the mozzi_config.h to 44100");
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stop();
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}
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// We send the test signal via A2DP - so we conect to the MyMusic Bluetooth Speaker
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out.begin(TX_MODE, "MyMusic");
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Serial.println("A2DP is connected now...");
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ratio = float_to_Q8n8(3.0f); // define modulation ratio in float and convert to fixed-point
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kNoteChangeDelay.set(200); // note duration ms, within resolution of CONTROL_RATE
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aModDepth.setFreq(13.f); // vary mod depth to highlight am effects
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randSeed(); // reseed the random generator for different results each time the sketch runs
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mozzi.begin(CONTROL_RATE);
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}
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void updateControl(){
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static Q16n16 last_note = octave_start_note;
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if(kNoteChangeDelay.ready()){
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// change octave now and then
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if(rand((byte)5)==0){
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last_note = 36+(rand((byte)6)*12);
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}
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// change step up or down a semitone occasionally
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if(rand((byte)13)==0){
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last_note += 1-rand((byte)3);
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}
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// change modulation ratio now and then
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if(rand((byte)5)==0){
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ratio = ((Q8n8) 1+ rand((byte)5)) <<8;
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}
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// sometimes add a fractionto the ratio
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if(rand((byte)5)==0){
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ratio += rand((byte)255);
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}
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// step up or down 3 semitones (or 0)
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last_note += 3 * (1-rand((byte)3));
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// convert midi to frequency
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Q16n16 midi_note = Q8n0_to_Q16n16(last_note);
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carrier_freq = Q16n16_to_Q24n8(Q16n16_mtof(midi_note));
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// calculate modulation frequency to stay in ratio with carrier
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mod_freq = (carrier_freq * ratio)>>8; // (Q24n8 Q8n8) >> 8 = Q24n8
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// set frequencies of the oscillators
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aCarrier.setFreq_Q24n8(carrier_freq);
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aModulator.setFreq_Q24n8(mod_freq);
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// reset the note scheduler
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kNoteChangeDelay.start();
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}
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}
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AudioOutput_t updateAudio(){
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long mod = (128u+ aModulator.next()) * ((byte)128+ aModDepth.next());
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return MonoOutput::fromNBit(24, mod * aCarrier.next());
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}
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// Arduino loop
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void loop() {
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if (out)
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copier.copy();
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}

‎src/AudioConfig.h‎

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* @brief Optional Functionality - comment out if not wanted
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*/
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// Activate ESP32 Audio - for ESP32, ESP8266 and Raspberry Pico
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#define USE_ESP8266_AUDIO
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// Activate the A2DP library - for ESP32 only
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#ifdef ESP32
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#define USE_A2DP
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#endif
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#define DEFAUT_ADC_PIN 34
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#define I2S_TAG "I2S"
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#define AUDIO_TAG "AUDIO"
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/**
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* @brief Platform specific Settings
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*
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#define PIN_I2S_MUTE 23
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#define SOFT_MUTE_VALUE LOW
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#endif
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#ifdef ESP8266

‎src/AudioMozzi.h‎

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#pragma once
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#include "mozzi_config.h"
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#include "hardware_defines.h"
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#include "mozzi_analog.h"
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#include "MozziGuts.h"
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unsigned long total_tick_count = 0;
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unsigned long audioTicks() {
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return total_tick_count;
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}
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namespace audio_tools {
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/**
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* @brief Support for https://sensorium.github.io/Mozzi/
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* Define your updateControl() method.
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* Define your updateAudio() method.
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* Start by calling begin(control_rate)
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* do not call audioHook(); in the loop !
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* @author Phil Schatzmann
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* @copyright GPLv3
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*
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*/
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class MozziGenerator : public SoundGenerator<int16_t> {
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public:
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MozziGenerator(int control_rate){
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info.sample_rate = AUDIO_RATE;
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info.bits_per_sample = 16;
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info.channels = 2;
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control_counter_max = info.sample_rate / control_rate;
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if (control_counter_max <= 0){
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control_counter_max = 1;
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}
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control_counter = control_counter_max;
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}
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/// Provides some key audio information
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AudioBaseInfo config() {
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return info;
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}
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/// Provides a single sample
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virtual int16_t readSample() {
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if (--control_counter<0){
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control_counter = control_counter_max;
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::updateControl();
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}
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int result = (int) ::updateAudio();
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total_tick_count++;
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return result;
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}
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protected:
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AudioBaseInfo info;
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int control_counter_max;
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int control_counter;
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};
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} // Namespace

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