Door Ajar Detection and Recovery for a Wireless Door Sensor

A wireless door sensor node for incorporation into a wireless personal area network, the wireless door sensor node including:

• a switch facilitating generating a door sensor status signal;
• a processor;
• and
• a non-transitory computer readable medium including computer-executable instructions, executable by the processor, for managing the wireless door sensor node 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, and
• re-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.

A transportable refrigerated container system including:

• a refrigeration system including a controller;
• a wireless communication system configured as a wireless personal area network (WPAN), the WPAN comprising:
• a wireless sensor node, configured to sense a status of a door in the refrigeration system and communicate the status of the door to a second node within the WPAN, the wireless sensor node comprising:
• a switch facilitating generating a sensor status signal indicating the status of the door;
• a processor;
• and
• a non-transitory computer readable medium including computer-executable instructions, executable by the processor, for managing the wireless door sensor node 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, and
• re-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.