Fig. 1

In A architecture of the instrumented lemming collar. The principal components are: the microprocessor (uP), with an ferroelectric memory (MEM); the ambient light sensor (ALS); the Real Time Clock (RTC) and a triggerable magnetic reed switch use to activate the device. In B algorithm of the light-sensitive collar. Intensity changes lead to analysis by the microprocessor only in situations when light level thresholds determined a priori are crossed. In C 3-D model (top), PCB assembly (center) and final device prototype (bottom)