Over the past decade, wireless sensor networks have advanced in terms of hardware design, communication protocols, and resource efficiency. Recently, there has been growing interest in mobility, and several small-profile sensing devices that control their own movement have been developed. In this paper, the authors present a navigation system implemented entirely on resource-constrained sensors. Localization is realized using triangulation in conjunction with radio interferometric angle-of-arrival estimation. A digital compass is employed to keep the mobile node on the desired trajectory. They also present a variation of the approach that uses a Kalman filter to estimate heading without using the compass. They demonstrate that a resource-constrained mobile sensor can accurately perform waypoint navigation with an average position error of 0.95 m.