An automatic, wireless audio recording node for analysis of beehives

Monitoring the sounds emitted by honey bees in a beehive is an important activity for beekeepers to ensure that their bee colonies remain healthy and to maximise productivity. A particular reproductive event called "swarming", involves the departure of a queen bee with a large portion of the hive population. Swarming can be identified through sound, and if allowed to occur unchecked can lead to a drop in hive productivity or, in extreme cases, colony death. A method of effectively alerting the keeper that such an event is imminent would aid in protecting the honey bee population and reducing beekeeping costs. In this paper, a solution using off the shelf Wireless Sensor Network (WSN) technologies with low power signal processing to monitor colony sound, as well as the temperature and humidity of the hive interior is presented. The system provides alerts to the beekeeper when an event is detected. The node was designed to work with a larger sensor network designed for monitoring health and conditions of the beehive, and uses the network from this system to send alerts. An interrupt circuit provided a wake up signal to the node when the sound associated with an important event was detected. This made the solution ultra-low power, by turning on the recording circuits only when they were explicitly required. In this paper the design and development of the prototype system is described, with the results of preliminary tests and analysis. A power analysis and energy budget confirmed that the final solution was energy neutral, providing additional energy for recharging, even in the case of several recording alerts in a single day.