Door ajar detection and recovery for a wireless door sensor

摘要

A refrigerated container system is described that includes a wireless personal area network (WPAN) including a plurality of wireless sensor nodes and a coordinator node through which the sensors provide sensor data to a controller for the refrigerated container system. The wireless sensors and the coordinator incorporate a variety of features that ensure efficient utilization of battery life by preventing unintended pairing of sensors with other WPANs and excessive sensor signal processing arising from door chatter. Finally, pairing is performed without pressing a button on the wireless door sensor. Instead, the sensor's magnetic reed switch is enlisted to detect swiping of a magnet by a user to enter a pairing mode.

主权项

1. A method of managing a wireless door sensor to avoid excessive sensor signal processing arising from a chattering door sensor signal stream, the method comprising:
detecting, by the wireless door sensor, a specified number of door transitions within a specified time period, and in response to said detecting:
disabling a door signal transition event processing routine;enabling a timer-based door sensor signal processing routine, wherein the timer-based routine reads a door sensor signal status regardless of whether a door signal transition has occurred, andre-enabling the door signal transition event processing routine in response to reading a same value for the door sensor signal status multiple times over a time duration, such multiple readings being indicative of the door position being stabilized.