AP_Notify: add parameter for logic level buzzer sounds at

libraries/AP_Notify/AP_Notify.cpp

@@ -147,6 +147,15 @@ const AP_Param::GroupInfo AP_Notify::var_info[] = {
     // @User: Advanced
     AP_GROUPINFO("LED_TYPES", 6, AP_Notify, _led_type, BUILD_DEFAULT_LED_TYPE),
 
+#if !defined(HAL_BUZZER_PIN)
+    // @Param: BUZZ_ON_LVL
+    // @DisplayName: Buzzer-on pin logic level
+    // @Description: Specifies pin level that indicates buzzer should play
+    // @Values: 0:LowIsOn,1:HighIsOn
+    // @User: Advanced
+    AP_GROUPINFO("BUZZ_ON_LVL", 7, AP_Notify, _buzzer_level, 1),
+#endif
+
     AP_GROUPEND
 };
 

libraries/AP_Notify/AP_Notify.h

@@ -151,6 +151,7 @@ public:
 
     static const struct AP_Param::GroupInfo var_info[];
     uint8_t get_buzz_pin() const  { return _buzzer_pin; }
+    uint8_t get_buzz_level() const  { return _buzzer_level; }
 
 private:
 
@@ -169,6 +170,7 @@ private:
     AP_Int8 _oreo_theme;
     AP_Int8 _buzzer_pin;
     AP_Int32 _led_type;
+    AP_Int8 _buzzer_level;
 
     char _send_text[NOTIFY_TEXT_BUFFER_SIZE];
     uint32_t _send_text_updated_millis; // last time text changed

libraries/AP_Notify/Buzzer.cpp

@@ -22,8 +22,13 @@
 #include "AP_Notify.h"
 
 #ifndef HAL_BUZZER_ON
- #define HAL_BUZZER_ON 1
- #define HAL_BUZZER_OFF 0 
+  #if !defined(HAL_BUZZER_PIN)
+    #define HAL_BUZZER_ON (pNotify->get_buzz_level())
+    #define HAL_BUZZER_OFF (!pNotify->get_buzz_level())
+  #else
+    #define HAL_BUZZER_ON 1
+    #define HAL_BUZZER_OFF 0 
+  #endif
 #endif