Basic structure of the buffer is there, but needs testing and debugging

FM/FM.ino

@@ -13,6 +13,8 @@ MIDI_CREATE_DEFAULT_INSTANCE();
 #define MIDI_CHANNEL 3
 
 bool gate = 0;
+byte noteBuffer[8];
+byte bufferIndex = 0;
 
 // desired intensity max and min, for AutoMap, note they're inverted for reverse dynamics
 const int MIN_INTENSITY = 700;
@@ -54,19 +56,51 @@ int carrier_freq;
 
 void noteOn(byte channel, byte note, byte velocity) {
   if (channel == MIDI_CHANNEL) {
-    carrier_freq = mtof((int) note);
     gate = 1;
+    updateBuffer(note, gate);
+    //playNote(); // this is called from within buffer update
   }
 }
 
 void noteOff(byte channel, byte note, byte velocity) {
   if (channel == MIDI_CHANNEL) {
     gate = 0;
+    updateBuffer(note, gate);
   }
 }
 
+void updateBuffer(byte bNote, bool bGate) {
+  if (bGate == 1) {
+    noteBuffer[bufferIndex] = bNote;
+    playNote();
+    bufferIndex++;
+  }
+  if (bGate == 0 && bufferIndex != 0) {
+    for (int i = 0; i <= bufferIndex; i++) {
+      if (noteBuffer[i] == bNote) {
+        // Removing the note from the array and shifting everything to close the gap 
+        for (int n = i; n <= bufferIndex; n++) {
+          noteBuffer[n] = noteBuffer[n + 1]; // what happens if it's the last note in buffer?
+        }      
+        if (i == bufferIndex) {
+          bufferIndex--;
+          playNote();
+        } else {
+          bufferIndex--;
+        }
+      }
+    }
+  }
+}
+
+void playNote() {
+  byte note = noteBuffer[bufferIndex];
+  carrier_freq = mtof((int) note);
+}
+
 void setup(){
-  pinMode(LED_BUILTIN_TX,INPUT); //switch rx and tx leds of, so they don't blink on midi
+  // switch rx and tx leds of, so they don't blink on midi
+  pinMode(LED_BUILTIN_TX,INPUT);
   pinMode(LED_BUILTIN_RX,INPUT);
 
   startMozzi();