Several fixes.

Added functions for detecting voices which do not produce any output.
Fixing screen changing when volume encoder was moved.

MicroDexed.ino

@@ -123,6 +123,8 @@ uint8_t effect_delay_feedback = 0;
 uint8_t effect_delay_volume = 0;
 bool effect_delay_sync = 0;
 elapsedMicros fill_audio_buffer;
+elapsedMillis control_rate;
+uint8_t shutdown_voices = 0;
 
 #ifdef SHOW_CPU_LOAD_MSEC
 elapsedMillis cpu_mem_millis;
@@ -335,6 +337,21 @@ void loop()
   // MIDI input handling
   check_midi_devices();
 
+  // Shutdown unused voices
+  if (control_rate > CONTROL_RATE_MS)
+  {
+    uint8_t tmp = shutdown_voices;
+    control_rate = 0;
+    dexed->getNumNotesPlaying();
+
+    if (tmp != shutdown_voices)
+    {
+      Serial.print(F("Active voices ["));
+      Serial.print(shutdown_voices);
+      Serial.println(F("]"));
+    }
+  }
+
 #ifdef I2C_DISPLAY
   // UI
   if (master_timer >= TIMER_UI_HANDLING_MS)

UI.cpp

@@ -235,6 +235,11 @@ void handle_ui(void)
         case 1: // right encoder moved
           switch (ui_state)
           {
+            case UI_VOLUME:
+              ui_state = UI_MAIN;
+              lcd.clear();
+              ui_show_main();
+              break;
             case UI_MAIN:
               switch (ui_main_state)
               {

config.h

@@ -60,6 +60,7 @@
 //* DEXED AND EFECTS SETTINGS
 //*************************************************************************************************
 #define DEXED_ENGINE DEXED_ENGINE_MODERN // DEXED_ENGINE_MARKI // DEXED_ENGINE_OPL
+#define CONTROL_RATE_MS 200
 
 // EFFECTS
 #define FILTER_MAX_FREQ 10000

dexed.cpp

@@ -63,7 +63,7 @@ Dexed::Dexed(int rate)
     voices[i].live = false;
   }
 
-  max_notes = 16;
+  max_notes = MAX_NOTES;
   currentNote = 0;
   resetControllers();
   controllers.masterTune = 0;
@@ -391,6 +391,53 @@ uint8_t Dexed::getMaxNotes(void)
   return max_notes;
 }
 
+uint8_t Dexed::getNumNotesPlaying(void)
+{
+  uint8_t op_carrier = controllers.core->get_carrier_operators(data[134]); // look for carriers
+  uint8_t i;
+  uint8_t count_playing_voices=0;
+
+  for (i = 0; i < max_notes; i++)
+  {
+    if (voices[i].live == true)
+    {
+      uint8_t op_amp = 0;
+      uint8_t op_carrier_num = 0;
+
+      memset(&voiceStatus, 0, sizeof(VoiceStatus));
+
+      voices[i].dx7_note->peekVoiceStatus(voiceStatus);
+
+      for (uint8_t op = 0; op < 6; op++)
+      {
+        if ((op_carrier & (1 >> op)) == 1)
+        {
+          {
+            // this voice is a carrier!
+            op_carrier_num++;
+
+            if (voiceStatus.amp[op] <= 1069 && voiceStatus.ampStep[op] == 4) // this voice produces no audio output
+              op_amp++;
+          }
+        }
+      }
+
+      if (op_amp == op_carrier_num)
+      {
+        // all carrier-operators are silent -> disable the voice
+        voices[i].live = false;
+        voices[i].sustained = false;
+        voices[i].keydown = false;
+        Serial.print(F("Voice shutdown: "));
+        Serial.println(i, DEC);
+      }
+      else
+        count_playing_voices++;
+    }
+  }
+  return(count_playing_voices);
+}
+
 bool Dexed::loadSysexVoice(uint8_t* new_data)
 {
   uint8_t* p_data = data;

dexed.h

@@ -160,6 +160,7 @@ class Dexed
     void keydown(uint8_t pitch, uint8_t velo);
     void setSustain(bool sustain);
     bool getSustain(void);
+    uint8_t getNumNotesPlaying(void);
 
     ProcessorVoice voices[MAX_NOTES];
     Controllers controllers;
@@ -190,6 +191,7 @@ class Dexed
     bool monoMode;
     bool refreshVoice;
     uint8_t engineType;
+    VoiceStatus voiceStatus;
     Lfo lfo;
     FmCore* engineMsfa;
     EngineMkI* engineMkI;