Sub: Warn for leak detection

ArduSub/ArduSub.cpp

@@ -460,6 +460,8 @@ void Sub::dataflash_periodic(void)
 // three_hz_loop - 3.3hz loop
 void Sub::three_hz_loop()
 {
+	set_leak_status(water_detector.update());
+
     // check if we've lost contact with the ground station
     failsafe_gcs_check();
 

ArduSub/Sub.h

@@ -302,6 +302,8 @@ private:
         uint8_t gcs                 : 1; // 4   // A status flag for the ground station failsafe
         uint8_t ekf                 : 1; // 5   // true if ekf failsafe has occurred
         uint8_t terrain             : 1; // 6   // true if the missing terrain data failsafe has occurred
+        uint8_t leak				: 1; // true if leak recently detected
+        uint32_t last_leak_warn_ms;      // last time a leak warning was sent to gcs
 
         int8_t radio_counter;            // number of iterations with throttle below throttle_fs_value
 
@@ -1050,6 +1052,8 @@ private:
     void dataflash_periodic(void);
     void accel_cal_update(void);
 
+    void set_leak_status(bool status);
+
 public:
     void mavlink_delay_cb();
     void failsafe_check();

ArduSub/events.cpp

@@ -73,6 +73,17 @@ void Sub::failsafe_battery_event(void)
 
 }
 
+void Sub::set_leak_status(bool status) {
+	uint32_t tnow = AP_HAL::millis();
+
+	failsafe.leak = status;
+
+	if(failsafe.leak && tnow > failsafe.last_leak_warn_ms + 5000) {
+		failsafe.last_leak_warn_ms = tnow;
+		gcs_send_text_fmt(MAV_SEVERITY_WARNING, "Leak Detected");
+	}
+}
+
 // failsafe_gcs_check - check for ground station failsafe
 void Sub::failsafe_gcs_check()
 {