Measure joystick input lag on PC

Measuring controller / joystick input lag to a computer is not as trivial as one might think. We encourage at least skimming the references below, especially the Lagmeter readme to get background. In short, take a video camera or smartphone capable of 60 frames/second or faster and use an LED wired to the joystick input and video it and the computer display while pressing a button. Video display lag (put the monitor in “game mode” if available) and USB polling cadence are two of several significant factors in input lag. In difficult absolute measurement scenarios such as this, where so many confounding factors are present, a more useful metric may be relative delay measurements, for example wired vs. wireless controllers.