We present an open-source software for UAV localization in a known environment, using only a few distance measurements. We demonstrate this software on a Crazyflie 2.1+ lightweight drone equipped with a ToF range sensor “crown”, looking forward, backward, left, right, and down. We show that even as few as five distance measurements suffice to reduce the set of possible locations to a small, finite collection of distinct poses. For comparison, the drone is also equipped with an extrinsic localization capability by triangulation with SteamVR Lighthouses; we show that our method usually returns a location that is reasonably close to the pose estimated by the extrinsic method, while having the advantage of not requiring careful placement of auxiliary tools (beacons) in the room. Our technique utilizes multiprocessing, runs in sub-second time, and is easy to use. Finally, we propose a more elaborate crown design featuring sixteen range sensors that look downwards at a 45-degree angle, which in total cost less than 32 USD. We show that such a design usually yields one or two possible locations that are close to the ground truth location.