  The Perspective-n-Point problem aims to estimate the relative pose between a
calibrated monocular camera and a known 3D model, by aligning pairs of 2D
captured image points to their corresponding 3D points in the model. We suggest
an algorithm that runs on weak IoT devices in real-time but still provides
provable theoretical guarantees for both running time and correctness. Existing
solvers provide only one of these requirements. Our main motivation was to turn
the popular DJI's Tello Drone (<90gr, <\$100) into an autonomous drone that
navigates in an indoor environment with no external human/laptop/sensor, by
simply attaching a Raspberry PI Zero (<9gr, <\$25) to it. This tiny
micro-processor takes as input a real-time video from a tiny RGB camera, and
runs our PnP solver on-board. Extensive experimental results, open source code,
and a demonstration video are included.
