The Lighthouse Localization System V2, originally designed by Valve/HTC Vive, was developed for motion tracking in virtual reality headsets. In this talk, we will introduce the operational principles of this system and present a lighthouse decoding and tracking algorithm implemented on a low-power wireless microcontroller, with hardware designed in a compact, centimeter-scale form factor. Our open-source implementation achieves an accuracy of 7.25 mm RMS for 2D motion tracking and 11.2 mm RMS for 3D motion tracking. We believe this system offers a low-cost alternative to expensive, camera-based motion capture systems.