One apparatus embodiment includes an electronic assembly, equipped to sense one or more changes in an environmental condition. The assembly includes a logic circuit coupled to: one or more environmental sensors, memory that provides data storage, and a wireless communicator. The logic circuit is configured to perform time measurement, perform environmental measurement with the one or more environmental sensors, store time-stamped environmental data in the memory, and communicate with particular other electronic assemblies, equipped to sense one or more changes in an environmental condition, via the wireless communicator. The logic circuit is also coupled to a power source that provides power to at least one of the logic circuit and the wireless communicator.