The smartphone and low-cost microcontroller as an AC circuit study kit for high school

Abstract

This article presents a smartphone and a low-cost microcontroller-based AC circuit educational module focusing on the measurements of alternating voltage, frequency, and phase shift as well as learning about a phasor diagram. A smartphone provides a signal generator as a signal source, the ESP32 microcontroller works for signal acquisition and the beadboard RC series circuit is a test circuit. In-house developed software, based on Microsoft Visual Basic (VB), was used for monitoring the input signal like an oscilloscope. The measured frequency and phase shift agree with the results obtained from the commercial oscilloscope benchtop. This developed module is an apparatus that may be useful in online learning situations with the home experiment during the pandemic situation and used in high school that lacks the instruments, i.e., function generator and oscilloscope.