  We present Warp, a hardware platform to support research in approximate
computing, sensor energy optimization, and energy-scavenged systems. Warp
incorporates 11 state-of-the-art sensor integrated circuits, computation, and
an energy-scavenged power supply, all within a miniature system that is just
3.6 cm x 3.3 cm x 0.5 cm. Warp's sensor integrated circuits together contain a
total of 21 sensors with a range of precisions and accuracies for measuring
eight sensing modalities of acceleration, angular rate, magnetic flux density
(compass heading), humidity, atmospheric pressure (elevation), infrared
radiation, ambient temperature, and color. Warp uses a combination of analog
circuits and digital control to facilitate further tradeoffs between sensor and
communication accuracy, energy efficiency, and performance. This article
presents the design of Warp and presents an evaluation of our hardware
implementation. The results show how Warp's design enables performance and
energy efficiency versus ac- curacy tradeoffs.
