Filter: Allow all filter frequencies to be 16bit.

libraries/Filter/NotchFilter.cpp

@@ -75,7 +75,7 @@ const AP_Param::GroupInfo NotchFilterParams::var_info[] = {
     // @Param: FREQ
     // @DisplayName: Frequency
     // @Description: Notch center frequency in Hz
-    // @Range: 10 200
+    // @Range: 10 400
     // @Units: Hz
     // @User: Advanced
     AP_GROUPINFO("FREQ", 2, NotchFilterParams, _center_freq_hz, 80),
@@ -83,7 +83,7 @@ const AP_Param::GroupInfo NotchFilterParams::var_info[] = {
     // @Param: BW
     // @DisplayName: Bandwidth
     // @Description: Notch bandwidth in Hz
-    // @Range: 5 50
+    // @Range: 5 100
     // @Units: Hz
     // @User: Advanced
     AP_GROUPINFO("BW", 3, NotchFilterParams, _bandwidth_hz, 20),

libraries/Filter/NotchFilter.h

@@ -49,14 +49,14 @@ public:
     static const struct AP_Param::GroupInfo var_info[];
 
     uint16_t center_freq_hz(void) const { return _center_freq_hz; }
-    uint8_t bandwidth_hz(void) const { return _bandwidth_hz; }
+    uint16_t bandwidth_hz(void) const { return _bandwidth_hz; }
     float attenuation_dB(void) const { return _attenuation_dB; }
     uint8_t enabled(void) const { return _enable; }
     
 private:
     AP_Int8 _enable;
     AP_Int16 _center_freq_hz;
-    AP_Int8 _bandwidth_hz;
+    AP_Int16 _bandwidth_hz;
     AP_Float _attenuation_dB;
 };