Real-Time Monitoring System for Electric Vehicle Chargers Based on IoT and ESP32 Microcontroller

Abstract

This work presents the design, implementation, and experimental validation of a real-time monitoring module for electric vehicle chargers (EVSE), based on the ESP32 microcontroller and IoT technologies. The system acquires critical electrical variables (voltage, current, and power) through Modbus RTU over RS485 communication with an energy meter, and integrates a DS18B20 temperature sensor for thermal supervision. Data are displayed locally on a TFT screen and remotely through an embedded web server accessible via Wi-Fi. Tests performed on a commercial One-S charger demonstrate that the solution is stable, reliable, and capable of reflecting real-time changes between charging and no-load states without interfering with the equipment's operation. The proposed system offers an economical, scalable, and easily implementable alternative to increase operational transparency and monitoring capabilities in mid-to-low-end EVSE, thereby contributing to a safer, more efficient charging infrastructure prepared for integration into smart grids.