Fixes and PT8211 enabled.

Now it works!

MicroMDAPiano.ino

@@ -235,8 +235,8 @@ void loop()
 #ifndef TEENSY_AUDIO_BOARD
     for (uint8_t i = 0; i < AUDIO_BLOCK_SAMPLES; i++)
     {
-      audio_buffer_r[i] *= vol_r;
-      audio_buffer_l[i] *= vol_l;
+      audio_buffer_r[i] *= vol;
+      audio_buffer_l[i] *= vol;
     }
 #endif
     queue_r.playBuffer();
@@ -530,7 +530,6 @@ void set_volume(float v, float vr, float vl)
 #ifdef TEENSY_AUDIO_BOARD
   sgtl5000_1.dacVolume(vol * vol_left, vol * vol_right);
 #else
-  volume_master.gain(vol);
   volume_r.gain(vr);
   volume_l.gain(vl);
 #endif

config.h

@@ -30,8 +30,8 @@
 
 // Initial values
 #define MIDI_DEVICE Serial1
-//#define USE_ONBOARD_USB_HOST 1
-#define TEENSY_AUDIO_BOARD 1
+#define USE_ONBOARD_USB_HOST 1
+//#define TEENSY_AUDIO_BOARD 1
 #define VOLUME 0.3
 #define DEFAULT_MIDI_CHANNEL MIDI_CHANNEL_OMNI
 #define AUDIO_MEM 300
@@ -57,7 +57,7 @@
 #define SHOW_CPU_LOAD_MSEC 5000
 
 // Enable TEST_NOTE for adding code to drop some midi notes for testing without keyboard
-#define TEST_NOTE MIDI_E2
+//#define TEST_NOTE MIDI_E2
 #define TEST_VEL_MIN 60
 #define TEST_VEL_MAX 110