Ensure devices return None if no update

Author: dala318

binary_sensor.py

@@ -160,4 +160,6 @@ def async_update_callback(self):
                 self._attr,
                 None,
             )
-            self.async_write_ha_state()
+        else:
+            self._state = None
+        self.async_write_ha_state()

lib/device.py

@@ -218,6 +218,8 @@ def close(self):
             self._socket.close()
         except:
             pass
+        for callback in self._callbacks:
+            callback()
 
     def get_measurements_and_empty(self):
         meas = self._measurements

sensor.py

@@ -150,4 +150,6 @@ def async_update_callback(self):
                 self._attr,
                 None,
             )
-            self.async_write_ha_state()
+        else:
+            self._state = None
+        self.async_write_ha_state()