Design and Hardware Architecture of a Modular Expansion Gateway for Industrial Applications

Sammanfattning

In recent years, the growing use of the Industrial Internet of Things (IIoT) has increased the demand for compact and efficient edge computing solutions capable of handling both data processing and power distribution. This thesis presents the design and implementation of a modular expansion gateway based on the Raspberry Pi Compute Module 5 (CM5), intended for industrial applications. The work focuses on the development of a custom 6-layer carrier printed circuit board (PCB), integrating power management, communication interfaces, and modular connectivity. The design includes a 24 V input stage, local voltage regulation for 5 V and 3.3 V rails, and a boost converter generating approximately 54 V to support Power over Ethernet (PoE). The system also features a board-to-board connector for modular expansion and a 40-pin header with Arduino-compatible interfaces, enabling communication through GPIO, I2C, SPI, and UART. The PCB was designed using KiCad and manufactured through an automated assembly process. Experimental validation confirmed correct voltage levels, including a measured 5 V rail of approximately 5.08 V, a 3.3 V rail of approximately 3.33 V, and a PoE output voltage of approximately 54.7 V. The tests also verified stable power delivery, PoE functionality with an external network camera, and functional communication through I2C, SPI, and UART interfaces. The results demonstrate that the developed expansion board provides a compact and flexible platform for industrial edge applications by integrating power regulation, PoE support, and communication interfaces into a single hardware solution.