Autonomous Reconfigurable Event Sensor (ARES) System

Author(s):

Sean Heintzelman

Abstract:

ARL’s Electric-/Magnetic-field sensing team has successfully demonstrated three different prototype low size, weight, and power sensor systems for measuring and analyzing ultra-low-frequency (30–300 Hz) electric and magnetic fields. These Autonomous Reconfigurable Event Sensor (ARES) systems exhibit low size, weight, power, and cost characteristics; volume and weight on the order of a deck of playing cards (75–150 cm³, 50–100 g), low active power consumption (10–30 mW) to permit over 10 days of continuous operation on a cell-phone-sized battery (5–20 Wh), and a total system cost of under $1000. The size and power consumption also permits indefinite operation in a sunny environment with a 50–100 cm² integrated solar panel. This report provides an overview for one of the three prototype ARES-class sensor systems: ARL-ARES. This system was designed and built in-house at ARL. It is a novel sensor system that includes a custom-designed 2.125- × 3.125-inch printed circuit board, a small 5-Wh LiPo battery, and a custom 3D-printed enclosure. Power consumption less than 25 mW, frequency bandwidth of 0 Hz – 2 kHz, and wireless communication using standard Bluetooth low-energy protocols have been demonstrated. ARL-ARES additionally has a modular interface to permit other communications options (e.g., inter-integrated circuit, serial peripheral interface, or universal asynchronous receiver–transmitter). This ARES form factor has one integrated D-dot (electric-field) sensor and two integrated Hall-effect (magnetic-field) sensors to measure 0–2 kHz local electric and magnetic fields but can also accept up to six external analog sensors for alternative applications with similar bandwidth.