Added simple synth example with Mono Last operation.

Author: Francois Best

res/Examples/MIDI_SimpleSynth/MIDI_SimpleSynth.ino

@@ -0,0 +1,81 @@
+#include <MIDI.h>
+#include "noteList.h"
+#include "pitches.h"
+
+#ifdef ARDUINO_SAM_DUE // Due has no tone function (yet), overriden to prevent build errors.
+#define tone(...)
+#define noTone(...)
+#endif
+
+// This example shows how to make a simple synth out of an Arduino, using the
+// tone() function. It also outputs a gate signal for controlling external
+// analog synth components (like envelopes).
+
+static const unsigned sGatePin     = 13;
+static const unsigned sAudioOutPin = 10;
+static const unsigned sMaxNumNotes = 16;
+MidiNoteList<sMaxNumNotes> midiNotes;
+
+// -----------------------------------------------------------------------------
+
+void handleGateChanged(bool inGateActive)
+{
+    digitalWrite(sGatePin, inGateActive ? HIGH : LOW);
+}
+
+void pulseGate()
+{
+    handleGateChanged(false);
+    delay(1);
+    handleGateChanged(true);
+}
+
+// -----------------------------------------------------------------------------
+
+void handleNotesChanged()
+{
+    if (midiNotes.empty())
+    {
+        handleGateChanged(false);
+        noTone(sAudioOutPin);
+    }
+    else
+    {
+        byte currentNote = 0;
+        if (midiNotes.getTail(currentNote))
+        {
+            tone(sAudioOutPin, sNotePitches[currentNote]);
+            pulseGate(); // Retrigger envelopes. Remove for legato effect.
+        }
+    }
+}
+
+// -----------------------------------------------------------------------------
+
+void handleNoteOn(byte inChannel, byte inNote, byte inVelocity)
+{
+    midiNotes.add(MidiNote(inNote, inVelocity));
+    handleNotesChanged();
+}
+
+void handleNoteOff(byte inChannel, byte inNote, byte inVelocity)
+{
+    midiNotes.remove(inNote);
+    handleNotesChanged();
+}
+
+// -----------------------------------------------------------------------------
+
+void setup()
+{  
+    pinMode(sGatePin,     OUTPUT);
+    pinMode(sAudioOutPin, OUTPUT);
+    MIDI.setHandleNoteOn(handleNoteOn);
+    MIDI.setHandleNoteOff(handleNoteOff);
+    MIDI.begin();
+}
+
+void loop()
+{
+    MIDI.read();
+}

res/Examples/MIDI_SimpleSynth/noteList.cpp

@@ -0,0 +1,21 @@
+/*!
+ *  \file       synth-core_NoteList.h
+ *  \author     Francois Best
+ *  \date       24/05/2013
+ *  \license    GPL v3.0 - Copyright Forty Seven Effects 2013
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "noteList.h"