Abstract
We present our efforts to design the first Visible Light Sensing (VLS) system that consumes only tens of mu Ws of power to sense and communicate. Our system requires no modification to the existing light infrastructure and uses unmodulated ambient light as sensing medium. We achieve this by designing a sensing mechanism that uses solar cells to achieve sub-mu Ws of power consumption. Further, we devise an ultra-low power backscatter based transmission mechanism we call Scatterlight that transmits digital readings without incurring the processing and computation overhead of existing sensors. Based on these principles we build a preliminary prototype. Our initial results demonstrate its ability to sense and communicate three hand gestures at 20 mu Ws of power.