Abstract
This paper describes EcoMicro, a miniature, self-powered, wireless inertial-sensing node in the volume of 8 × 13 × 9.5 mm 3 , including energy storage and solar cells. It is smaller than existing systems with similar functionality while retaining rich functionality and efficiency. It is capable of measuring motion using a inertial measurement unit (IMU) and communication over Bluetooth Low Energy (BLE) protocol. It is self-powered by miniature solar cells and can perform maximum power point tracking (MPPT). Its integrated energystorage device combines the longevity and power density of supercapacitors with the relatively flat discharge curve of batteries. Our power-ground gating circuit minimizes leakage current during sleep mode and is used in conjunction with the real-time-clock for duty cycling. Experimental results show EcoMicro to be operational and efficient for a class of wireless sensing applications.