Phase-sensitive detection in the undergraduate lab using a low-cost microcontroller

Phase-sensitive detection is an important experimental technique that allows signals to be extracted from noisy data. Commercial lock-in amplifiers, often used for phase-sensitive detection, are expensive and host a bewildering array of controls that may intimidate a novice user. Low-cost microcontrollers such as the Arduino family of devices might seem like a good match for learning about such devices, but making a self-contained device that includes a reference signal, a voltage input, a signal mixer, a filter, and a display is difficult. Here, we present the construction of a phase-sensitive detector (PSD) using an Arduino. (C) 2016 American Association of Physics Teachers.