Mozzi support

Author: pschatzmann

examples/streams-mozzi-a2dp/README.md

@@ -0,0 +1,74 @@
+# Using Mozzi on Bluetooth
+
+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).
+
+A standard Sketch will need to combine the Audio-Tools with the Mozzi Logic:
+
+```
+#include "AudioTools.h"
+#include "AudioA2DP.h"
+#include "AudioMozzi.h"
+// Mozzi includes
+// ....
+
+
+using namespace audio_tools;  
+
+// Audio Tools
+MozziGenerator mozzi(CONTROL_RATE);                       // subclass of SoundGenerator 
+GeneratedSoundStream<int16_t> in(mozzi, 2);               // Stream with 2 channels generated with mozzi
+A2DPStream out = A2DPStream::instance() ;                 // A2DP input - A2DPStream is a singleton!
+StreamCopy copier(out, in);                               // copy in to out 
+
+```
+
+As you can see above you can add the __MozziGenerator__ like any other Generator to the __GeneratedSoundStream__ class.
+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()__:
+
+```
+void setup(){
+  Serial.begin(115200);
+
+  if (mozzi.config().sample_rate!=44100){
+    Serial.println("Please set the AUDIO_RATE in the mozzi_config.h to 44100");
+    stop();
+  }
+
+  // We send the generated sound via A2DP - so we conect to the MyMusic Bluetooth Speaker
+  out.begin(TX_MODE, "MyMusic");
+  Serial.println("A2DP is connected now...");
+
+  // Add your Mozzi setup here
+  // ...
+  in.begin();
+}
+```
+
+Like in any other Mozzi Sketch you need to define the __updateControl()__
+
+```
+// Mozzi updateControl
+void updateControl(){
+}
+```
+
+And like in any other Mozzi Sketch you need to define the __updateAudio()__
+
+```
+// Mozzi updateAudio
+AudioOutput_t updateAudio(){
+}
+```
+
+In the loop you need to replace the __audioHook()__ with your copy logic:
+
+```
+// Arduino loop  
+void loop() {
+  if (out)
+    copier.copy();
+}
+```
+
+That's all to output the generated sound to a Bluetooth Speaker...
+

examples/streams-mozzi-a2dp/streams-mozzi-a2dp.ino

@@ -0,0 +1,121 @@
+/**
+ * @file streams-generator-a2dp.ino
+ * @author Phil Schatzmann
+ * @brief see https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/streams-generator-a2dp/README.md
+ * 
+ * @author Phil Schatzmann
+ * @copyright GPLv3
+ * 
+ */
+#include "AudioTools.h"
+#include "AudioA2DP.h"
+#include "AudioMozzi.h"
+#include <Oscil.h>
+#include <tables/cos2048_int8.h> // table for Oscils to play
+#include <mozzi_fixmath.h>
+#include <EventDelay.h>
+#include <mozzi_rand.h>
+#include <mozzi_midi.h>
+
+using namespace audio_tools;  
+
+typedef int16_t sound_t;                                  // sound will be represented as int16_t (with 2 bytes)
+uint8_t channels = 2;                                     // The stream will have 2 channels 
+MozziGenerator mozzi;                                     // subclass of SoundGenerator 
+GeneratedSoundStream<sound_t> in(mozzi, channels);        // Stream generated with mozzi
+A2DPStream out = A2DPStream::instance() ;                 // A2DP input - A2DPStream is a singleton!
+StreamCopy copier(out, in); // copy in to out
+
+/// Copied from AMsynth.ino
+#define CONTROL_RATE 64 // Hz, powers of 2 are most reliable
+
+// audio oscils
+Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aCarrier(COS2048_DATA);
+Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aModulator(COS2048_DATA);
+Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aModDepth(COS2048_DATA);
+
+// for scheduling note changes in updateControl()
+EventDelay  kNoteChangeDelay;
+
+// synthesis parameters in fixed point formats
+Q8n8 ratio; // unsigned int with 8 integer bits and 8 fractional bits
+Q24n8 carrier_freq; // unsigned long with 24 integer bits and 8 fractional bits
+Q24n8 mod_freq; // unsigned long with 24 integer bits and 8 fractional bits
+
+// for random notes
+Q8n0 octave_start_note = 42;
+
+
+void setup(){
+  Serial.begin(115200);
+
+  if (mozzi.info().sample_rate!=44100){
+    Serial.println("Please set the AUDIO_RATE in the mozzi_config.h to 44100");
+    stop();
+  }
+
+  // We send the test signal via A2DP - so we conect to the MyMusic Bluetooth Speaker
+  out.begin(TX_MODE, "MyMusic");
+  Serial.println("A2DP is connected now...");
+
+  ratio = float_to_Q8n8(3.0f);   // define modulation ratio in float and convert to fixed-point
+  kNoteChangeDelay.set(200); // note duration ms, within resolution of CONTROL_RATE
+  aModDepth.setFreq(13.f);     // vary mod depth to highlight am effects
+  randSeed(); // reseed the random generator for different results each time the sketch runs
+  mozzi.begin(CONTROL_RATE);
+}
+
+void updateControl(){
+  static Q16n16 last_note = octave_start_note;
+
+  if(kNoteChangeDelay.ready()){
+
+    // change octave now and then
+    if(rand((byte)5)==0){
+      last_note = 36+(rand((byte)6)*12);
+    }
+
+    // change step up or down a semitone occasionally
+    if(rand((byte)13)==0){
+      last_note += 1-rand((byte)3);
+    }
+
+    // change modulation ratio now and then
+    if(rand((byte)5)==0){
+      ratio = ((Q8n8) 1+ rand((byte)5)) <<8;
+    }
+
+    // sometimes add a fractionto the ratio
+    if(rand((byte)5)==0){
+      ratio += rand((byte)255);
+    }
+
+    // step up or down 3 semitones (or 0)
+    last_note += 3 * (1-rand((byte)3));
+
+    // convert midi to frequency
+    Q16n16 midi_note = Q8n0_to_Q16n16(last_note);
+    carrier_freq = Q16n16_to_Q24n8(Q16n16_mtof(midi_note));
+
+    // calculate modulation frequency to stay in ratio with carrier
+    mod_freq = (carrier_freq * ratio)>>8; // (Q24n8   Q8n8) >> 8 = Q24n8
+
+      // set frequencies of the oscillators
+    aCarrier.setFreq_Q24n8(carrier_freq);
+    aModulator.setFreq_Q24n8(mod_freq);
+
+    // reset the note scheduler
+    kNoteChangeDelay.start();
+  }
+}
+
+AudioOutput_t updateAudio(){
+  long mod = (128u+ aModulator.next()) * ((byte)128+ aModDepth.next());
+  return MonoOutput::fromNBit(24, mod * aCarrier.next());
+}
+
+// Arduino loop  
+void loop() {
+  if (out)
+    copier.copy();
+}

src/AudioConfig.h

@@ -10,7 +10,10 @@
  * @brief Optional Functionality - comment out if not wanted
  */
 
+// Activate ESP32 Audio - for ESP32, ESP8266 and Raspberry Pico
 #define USE_ESP8266_AUDIO
+
+// Activate the A2DP library - for ESP32 only
 #ifdef ESP32
 #define USE_A2DP
 #endif
@@ -33,7 +36,6 @@
 #define DEFAUT_ADC_PIN 34
 #define I2S_TAG "I2S"
 #define AUDIO_TAG "AUDIO"
-
 /**
  * @brief Platform specific Settings
  * 
@@ -50,6 +52,8 @@
 #define PIN_I2S_MUTE 23
 #define SOFT_MUTE_VALUE LOW  
 
+
+
 #endif
 
 #ifdef ESP8266

src/AudioMozzi.h

@@ -0,0 +1,64 @@
+#pragma once
+
+#include "mozzi_config.h"
+#include "hardware_defines.h"
+#include "mozzi_analog.h"
+#include "MozziGuts.h"
+
+unsigned long total_tick_count = 0;
+
+unsigned long audioTicks() {
+    return total_tick_count;
+}
+
+namespace audio_tools {
+
+/**
+ * @brief Support for  https://sensorium.github.io/Mozzi/ 
+ * Define your updateControl() method.
+ * Define your updateAudio() method.
+ * Start by calling begin(control_rate)
+ * do not call audioHook(); in the loop !
+
+ * @author Phil Schatzmann
+ * @copyright GPLv3
+ * 
+ */
+class MozziGenerator : public SoundGenerator<int16_t> {
+    public:
+        MozziGenerator(int control_rate){
+            info.sample_rate = AUDIO_RATE; 
+            info.bits_per_sample = 16;
+            info.channels = 2;
+            control_counter_max = info.sample_rate / control_rate;
+            if (control_counter_max <= 0){
+                control_counter_max = 1;
+            }
+            control_counter = control_counter_max;
+        }
+
+        /// Provides some key audio information
+        AudioBaseInfo config() {
+            return info;
+        }
+
+        /// Provides a single sample
+        virtual int16_t readSample() {
+            if (--control_counter<0){
+                control_counter = control_counter_max;
+                ::updateControl();
+            }
+            int result = (int) ::updateAudio();
+            total_tick_count++;
+            return result;
+        }
+
+    protected:
+        AudioBaseInfo info;
+        int control_counter_max;
+        int control_counter;
+
+};
+
+
+} // Namespace