  Increasing demand for larger touch screen panels (TSPs) places more energy
burden to mobile systems with conventional sensing methods. To mitigate this
problem, taking advantage of the touch event sparsity, this paper proposes a
novel TSP readout system that can obtain huge energy saving by turning off the
readout circuits when none of the sensors are activated. To this end, a novel
ultra-low-power always-on event and region of interest detection based on
lightweight compressed sensing is proposed. Exploiting the proposed event
detector, the context-aware TSP readout system, which can improve the energy
efficiency by up to 42x, is presented.
