Rethinking Power Efficiency for Next-Generation Processor-Free Sensing Devices

Sensors

Li Lu¹  Shengyu Li¹  Songfan Li¹  Yihang Song¹  Chong Zhang¹ 

[1] School of Computer Science and Engineering, University of Electronic Science and Technology of China, Qingshuihe Campus, Chengdu 611731, China;

关键词: backscatter sensing devices;    power optimization;    I²C;    processor-free devices;   

DOI  :  10.3390/s22083074

来源: DOAJ

【 摘 要 】

The last decade has seen significant advances in power optimization for IoT sensors. The conventional wisdom considers that if we reduce the power consumption of each component (e.g., processor, radio) into $\mathsf{\mu }$W-level of power, the IoT sensors could achieve overall ultra-low power consumption. However, we show that this conventional wisdom is overturned, as bus communication can take significant power for exchanging data between each component. In this paper, we analyze the power efficiency of bus communication and ask whether it is possible to reduce the power consumption for bus communication. We observe that existing bus architectures in mainstream IoT devices can be classified into either push-pull or open-drain architecture. push-pull only adapts to unidirectional communication, whereas open-drain inherently fits for bidirectional communication which benefits simplifying bus topology and reducing hardware costs. However, open-drain consumes more power than push-pull due to the high leakage current consumption while communicating on the bus. We present Turbo, a novel approach introducing low power to the open-drain based buses by reducing the leakage current created on the bus. We instantiate Turbo on I${}^2$C bus and evaluate it with commercial off-the-shelf (COTS) sensors. The results show a $76.9\%$ improvement in power efficiency in I${}^2$C communication.

【 授权许可】

Unknown