Refactor into files

MidiDriver.h

@@ -0,0 +1,26 @@
+#ifndef MIDI_DRIVER_H
+#define MIDI_DRIVER_H
+
+#include <Arduino.h>
+#include <pico/mutex.h>
+
+class MidiDriver {
+public:
+    MidiDriver();
+    void begin();
+    
+    void sendNoteOn(uint8_t note, uint8_t velocity, uint8_t channel);
+    void sendNoteOff(uint8_t note, uint8_t channel);
+    void sendRealtime(uint8_t status);
+    void panic(uint8_t channel);
+
+    void lock();
+    void unlock();
+
+private:
+    mutex_t _mutex;
+};
+
+extern MidiDriver midi;
+
+#endif