#ifndef _FILTER_H
#define _FILTER_H

#include <math.h>

#if !defined(_FUSION_TEST)
  #if (ARDUINO >= 100)
    #include "Arduino.h"
  #else
    #include "WProgram.h"
  #endif
#else
  #define PI  (M_PI)
#endif

#include "quaternion.h"

#define RAD_TO_DEG  (180.0F / PI)

class Filter {
public:
  Filter(void);
  
  void setAccelXYZ(const float x, const float y, const float z);
  void setCompassXYZ(const float x, const float y, const float z);
  void setGyroXYZ(const float x, const float y, const float z);
  
  virtual void process(void) = 0;
  
protected:
  float _accelData[3];
  float _compassData[3];
  float _gyroData[3];
};

#endif

#ifndef _FILTER_H
#define _FILTER_H

#include <math.h>

#if (ARDUINO >= 100)
 #include "Arduino.h"
#else
 #include "WProgram.h"
#endif

#include "quaternion.h"

#define RAD_TO_DEG  (180.0 / PI)

class Filter {
public:
  Filter(void);
  
  void setAccelXYZ(const float x, const float y, const float z);
  void setCompassXYZ(const float x, const float y, const float z);
  void setGyroXYZ(const float x, const float y, const float z);
  
  virtual void process(void) = 0;
  
protected:
  float _accelData[3];
  float _compassData[3];
  float _gyroData[3];
};

#endif

--- 
+++ 
@@ -3,15 +3,19 @@
 
 #include <math.h>
 
-#if (ARDUINO >= 100)
- #include "Arduino.h"
+#if !defined(_FUSION_TEST)
+  #if (ARDUINO >= 100)
+    #include "Arduino.h"
+  #else
+    #include "WProgram.h"
+  #endif
 #else
- #include "WProgram.h"
+  #define PI  (M_PI)
 #endif
 
 #include "quaternion.h"
 
-#define RAD_TO_DEG  (180.0 / PI)
+#define RAD_TO_DEG  (180.0F / PI)
 
 class Filter {
 public:
Allow for native unit testing
