You may want to check out hivetool.org
We have been running a Pi based hive monitor since October 2012 and have free open source software available. We are working on an optical bee counter using openCV. The system consists of an Adam Equipment scale, Pi, humidity and temperature sensors both in and out of the hive, microphone and camera.
We welcome any programmers, beekeepers, engineers, citizen scientists, researches to join our effort to install hive monitors around the world.
Also please see "http://www.scstatebeekeepers.org/Resour ... ents/intro
doc for website.pdf" for information on a grant from the South Carolina Beekeepers Association. The ten Pi systems we are installing across the state of South Carolina this summer will be the first state wide, online, realtime hive monitoring system.