The Role of ESP32 in Enabling Industry 4.0 and 5.0: A Comprehensive Narrative Review of Edge Intelligence, Human-Centric Automation, and Sustainable Innovation

Industry 4.0 and 5.0 mark two closely related yet distinct phases of industrial evolution. While the fourth wave centres on automation, interconnectivity and data-led processes through the Internet of Things (IoT), cyber-physical systems (CPS) and artificial intelligence (AI), the fifth wave builds on that groundwork to put people, the planet and recovery from shocks first. The ESP32, a low-cost but powerful microcontroller unit (MCU), plays a crucial role in both eras thanks to its built-in wireless radios, solid processing power and flexible pin layout. This narrative review examines how the ESP32 is shaping modern factory floors and wider industrial practice. We explore its use in smart production, predictive upkeep, edge computing, human-machine interfaces and green monitoring. The evidence shows that the ESP32 can lower entry barriers for intelligent manufacturing, enable on-the-spot choices, and blend virtual models with real machines in smooth, timely ways. We also consider what its rise means for digital twins, cybersecurity and long-term research directions.