AP_Proximity: add methods covering sensor health, enable and present

libraries/AP_Proximity/AP_Proximity.cpp

@@ -437,4 +437,17 @@ AP_Proximity::Proximity_Type AP_Proximity::get_type(uint8_t instance) const
     return Proximity_Type_None;
 }
 
+bool AP_Proximity::sensor_present() const
+{
+    return get_status() != Proximity_NotConnected;
+}
+bool AP_Proximity::sensor_enabled() const
+{
+    return _type[primary_instance] != Proximity_Type_None;
+}
+bool AP_Proximity::sensor_failed() const
+{
+    return get_status() != Proximity_Good;
+}
+
 AP_Proximity *AP_Proximity::_singleton;

libraries/AP_Proximity/AP_Proximity.h

@@ -134,6 +134,12 @@ public:
 
     static AP_Proximity *get_singleton(void) { return _singleton; };
 
+    // methods for mavlink SYS_STATUS message (send_extended_status1)
+    // these methods cover only the primary instance
+    bool sensor_present() const;
+    bool sensor_enabled() const;
+    bool sensor_failed() const;
+
 private:
     static AP_Proximity *_singleton;
     Proximity_State state[PROXIMITY_MAX_INSTANCES];