Several additions.

MicroMDAPiano.ino

@@ -29,22 +29,24 @@ Bounce but1 = Bounce(BUT1_PIN, 10);  // 10 ms debounce
 
 // GUItool: begin automatically generated code
 AudioPlayQueue           queue1;         //xy=494,404
+AudioPlayQueue           queue2;         //xy=494,404
 AudioAnalyzePeak         peak1;          //xy=695,491
+AudioAnalyzePeak         peak2;          //xy=695,491
 #ifdef TEENSY_AUDIO_BOARD
 AudioOutputI2S           i2s1;           //xy=1072,364
 AudioConnection          patchCord1(queue1, peak1);
-AudioConnection          patchCord2(queue1, 0, i2s1, 0);
-AudioConnection          patchCord3(queue1, 0, i2s1, 1);
+AudioConnection          patchCord2(queue2, peak2);
+AudioConnection          patchCord5(queue1, 0, i2s1, 0);
+AudioConnection          patchCord6(queue2, 0, i2s1, 1);
 AudioControlSGTL5000     sgtl5000_1;     //xy=700,536
 #else
 AudioOutputPT8211        pt8211_1;       //xy=1079,320
-AudioAmplifier           volume_master;           //xy=678,393
 AudioAmplifier           volume_r;           //xy=818,370
 AudioAmplifier           volume_l;           //xy=818,411
-AudioConnection          patchCord1(queue1, peak1);
-AudioConnection          patchCord2(queue1, volume_master);
-AudioConnection          patchCord3(volume_master, volume_r);
-AudioConnection          patchCord4(volume_master, volume_l);
+AudioConnection          patchCord1(queue1, volume_r);
+AudioConnection          patchCord2(queue2, volume_l);
+AudioConnection          patchCord3(volume_r, peak1);
+AudioConnection          patchCord4(volume_l, peak2);
 AudioConnection          patchCord5(volume_r, 0, pt8211_1, 0);
 AudioConnection          patchCord6(volume_l, 0, pt8211_1, 1);
 #endif
@@ -177,7 +179,8 @@ void setup()
 
 void loop()
 {
-  int16_t* audio_buffer; // pointer to AUDIO_BLOCK_SAMPLES * int16_t
+  int16_t* audio_buffer_r; // pointer to AUDIO_BLOCK_SAMPLES * int16_t
+  int16_t* audio_buffer_l; // pointer to AUDIO_BLOCK_SAMPLES * int16_t
   const uint16_t audio_block_time_ms = 1000000 / (SAMPLE_RATE / AUDIO_BLOCK_SAMPLES);
 
   while (42 == 42) // DON'T PANIC!
@@ -192,13 +195,18 @@ void loop()
 
     handle_input();
 
-    audio_buffer = queue1.getBuffer();
-    if (audio_buffer == NULL)
+    audio_buffer_r = queue1.getBuffer();
+    if (audio_buffer_r == NULL)
+    {
+      Serial.println(F("E: audio_buffer_r allocation problems!"));
+    }
+    audio_buffer_l = queue2.getBuffer();
+    if (audio_buffer_l == NULL)
     {
-      Serial.println(F("E: audio_buffer allocation problems!"));
+      Serial.println(F("E: audio_buffer_l allocation problems!"));
     }
     
-    if (!queue1.available())
+    if (!queue1.available() || !queue2.available())
       continue;
 
     elapsedMicros t1;
@@ -213,11 +221,18 @@ void loop()
       if (peak1.read() > 0.99)
         peak++;
     }
+    if (peak2.available())
+    {
+      if (peak2.read() > 0.99)
+        peak++;
+    }
 #ifndef TEENSY_AUDIO_BOARD
     for (uint8_t i = 0; i <= AUDIO_BLOCK_SAMPLES; i++)
-      audio_buffer[i] *= vol;
+      audio_buffer_r[i] *= vol_r;
+    audio_buffer_l[i] *= vol_l;
 #endif
     queue1.playBuffer();
+    queue2.playBuffer();
   }
 }
 void handle_input(void)

mdaEPiano.cpp

@@ -327,10 +327,10 @@ void mdaEPiano::guiGetDisplay(int32_t index, char *label)
 }
 */
 
-void mdaEPiano::process(float **inputs, float **outputs, int32_t sampleFrames)
+void mdaEPiano::process(int16_t **outputs_r, int16_t **outputs_l, int32_t sampleFrames)
 {
-	float* out0 = outputs[0];
-	float* out1 = outputs[1];
+	int16_t* out_l = outputs_r[0];
+	int16_t* out_r = outputs_l[0];
 	int32_t event=0, frame=0, frames, v;
   float x, l, r, od=overdrive;
   int32_t i;
@@ -375,8 +375,8 @@ void mdaEPiano::process(float **inputs, float **outputs, int32_t sampleFrames)
       l += l * lmod * lfo1;
       r += r * rmod * lfo1;  //worth making all these local variables?
 
-      *out0++ += l;
-      *out1++ += r;
+      *out_r++ += static_cast<int16_t>(l * 0x8000);
+      *out_l++ += static_cast<int16_t>(r * 0x8000);
     }
 
     if(frame<sampleFrames)

mdaEPiano.h

@@ -59,7 +59,7 @@ public:
 	  mdaEPiano(); // mdaEPiano(audioMasterCallback audioMaster);
 	~mdaEPiano();
 
-	virtual void process(float **inputs, float **outputs, int32_t sampleframes);
+	virtual void process(int16_t **outputs_r, int16_t **outputs_l, int32_t sampleFrames);
 	virtual void processReplacing(float **inputs, float **outputs, int32_t sampleframes);
 	virtual int32_t processEvents(); // virtual int32_t processEvents(VstEvents* events);