Reorganized file structure to allow building Arduino project

synth_engine.h

@@ -2,7 +2,33 @@
 #define SYNTH_ENGINE_H
 
 #include <stdint.h>
+
+#if defined(ARDUINO_ARCH_RP2040)
+#include <pico/mutex.h>
+class SynthMutex {
+public:
+    SynthMutex() { mutex_init(&mtx); }
+    void lock() { mutex_enter_blocking(&mtx); }
+    void unlock() { mutex_exit(&mtx); }
+private:
+    mutex_t mtx;
+};
+template <typename Mutex>
+class SynthLockGuard {
+public:
+    explicit SynthLockGuard(Mutex& m) : m_mutex(m) { m_mutex.lock(); }
+    ~SynthLockGuard() { m_mutex.unlock(); }
+    SynthLockGuard(const SynthLockGuard&) = delete;
+    SynthLockGuard& operator=(const SynthLockGuard&) = delete;
+private:
+    Mutex& m_mutex;
+};
+#else
 #include <mutex>
+using SynthMutex = std::mutex;
+template <typename Mutex>
+using SynthLockGuard = std::lock_guard<Mutex>;
+#endif
 
 /**
  * @class SynthEngine
@@ -85,9 +111,15 @@ public:
 
     static const int GRID_W = 12;
     static const int GRID_H = 12;
+    
+    static const size_t SERIALIZED_GRID_SIZE = GRID_W * GRID_H * 3;
+    void exportGrid(uint8_t* buffer);
+    void importGrid(const uint8_t* buffer);
+    void loadPreset(int preset);
+    void clearGrid();
 
     GridCell grid[GRID_W][GRID_H];
-    std::mutex gridMutex;
+    SynthMutex gridMutex;
 
     // Helper to process one sample step of the grid
     float processGridStep();