Graduate Seminar with Vishal Deep: Are We There Yet? Developing a Sense of Time in Intermittently-Powered Batteryless Sensor Nodes


September 29, 2021    
1:10 pm - 2:00 pm


3043 ECpE Building Addition
Coover Hall, Ames, Iowa, 50011

Event Type

Speaker: Vishal Deep, ECpE Graduate Student

Advisor: Henry Duwe

Title: Are We There Yet? Developing a Sense of Time in Intermittently-Powered Batteryless Sensor Nodes

Abstract: A notion of time is intrinsic to conventional battery-powered sensor nodes. Such nodes rely on time for data timestamping, checking for data freshness, and communication. However, an emerging sensor node paradigm that replaces fragile, life-limited, and potentially toxic batteries with energy-harvesting and capacitive energy buffers poses severe challenges to traditional modes of timekeeping. These batteryless systems operate intermittently i.e. it turns off completely when the capacitor reaches a voltage that can no longer support operation and remains off until sufficient energy is available to turn on the system. It happens because energy consumption is mostly higher than the harvested energy. During off times, traditional clocks lose track of time. This talk will introduce the current state-of-the-art in timekeeping for batteryless intermittent nodes, including my work on Heterogeneous Array of Redundant Persistent Clocks (HARC), a novel solution to the problem of timekeeping in such systems. I will then discuss the current challenges associated with having a shared sense of time in a network of such intermittently-powered nodes.

Bio: Vishal Deep is currently a Ph.D. student in Computer Engineering at Iowa State University. He received his M.S. degree from California State University, Fresno. His broad research interests include embedded systems, computer architecture, and the Internet of Things (IoT). He has a particular interest in developing computational and communication primitives for batteryless, intermittently-powered devices.