Index: dialin/hd/air_trap.py
===================================================================
diff -u -r858a23ec52b7a982ca68588a80a39a775d16a315 -reed13ddfba5bd65563145b6e5b9a882da851878e
--- dialin/hd/air_trap.py	(.../air_trap.py)	(revision 858a23ec52b7a982ca68588a80a39a775d16a315)
+++ dialin/hd/air_trap.py	(.../air_trap.py)	(revision eed13ddfba5bd65563145b6e5b9a882da851878e)
@@ -56,6 +56,7 @@
 
         self.lower_level = self.AIR_DETECTED_AT_LEVEL
         self.upper_level = self.AIR_DETECTED_AT_LEVEL
+        self.hd_air_trap_timestamp = 0.0
 
     def get_air_trap_levels(self):
         """
@@ -81,8 +82,8 @@
         """
         return self.upper_level
 
-    @publish(["lower_level", "upper_level"])
-    def _handler_air_trap_sync(self, message):
+    @publish(["hd_air_trap_timestamp", "lower_level", "upper_level"])
+    def _handler_air_trap_sync(self, message, timestamp=0.0):
         """
         Handles published air trap data messages.  Air trap data are captured
         for reference.
@@ -98,6 +99,7 @@
 
         self.lower_level = lower[0]
         self.upper_level = upper[0]
+        self.hd_air_trap_timestamp = timestamp
 
     def cmd_air_trap_level_sensor_override(self, sensor: int, detected: int, reset: int = NO_RESET) -> int:
         """