Power electronics has experienced a large growth due to several applications. For this reason, undergraduate laboratory classes should have modern equipment to improve the classes and allow the students to have the opportunity to understand theoretical concepts in practice. This paper presents the development of a low-cost didactic module for power electronics laboratory classes. The module is a DC-AC single-phase converter controlled by a Pulse Width Modulation (PWM) strategy. The project consists of software and hardware elements that allow the user to control the converter by an app in the mobile phone. The app send the parameters to the Arduino Mega 2560 microcontroller board that generates the pulses to control the switches in the converter. Experimental results done with Bipolar and Unipolar PWM control, varying the modulation index and the fundamental frequency demonstrated the quality of the didactic module in power electronics laboratory classes.