Development of an ESP32-based microcontroller system for current, power, and energy monitoring of generator units

Department of Electrical Engineering, Faculty of Vocational Studies, Universitas Negeri Surabaya, Indonesia

^* Corresponding author: amalia.irda@gmail.com

Published online: 22 December 2025

Abstract

The reliability of electrical systems in the industrial sector, especially shipping and logistics, relies on optimal generator unit performance as a backup power source. However, manual monitoring of generator electrical parameters such as current, power, and energy still poses risks of recording errors and delayed problem detection. To address this, this research designs and implements a generator electrical parameter monitoring system based on the ESP32 microcontroller using IoT technology. The system integrates PZEM-016 sensors for each phase (R, S, T) to measure current, power, and energy, with data transmitted via RS485 to TTL UART for ESP32 processing. Data is displayed locally through an OLED screen and can be accessed wirelessly via an HTML web server hosted by ESP32 in Access Point mode, eliminating the need for internet access. This study improves previous works by combining local and web- based real-time monitoring, adding Wi-Fi AP functionality, and enabling flexible remote access. The system undergoes testing with various load scenarios such as cell phone charger, laptop charger, and no load to demonstrate its accuracy and ability to differentiate load characteristics. Results show that the system accurately reads and displays data in real-time, enhances monitoring efficiency, and supports reliable generator operation monitoring in industrial environments.