Expansion Board for Portability: Battery, Bluetooth/WiFi/USB, SD and Graphical Interface

Abstract

The implementation of portability features in electronic prototypes requires the integration of multiple components for connectivity, data storage, power management, and user interfaces. Although these capabilities are available across various specialized development boards, there is currently no solution that integrates all of them into a single system. This work presents the design and experimental validation for the future implementation of an expansion board that includes Bluetooth, WiFi, and USB communication; local storage on a microSD card; an embedded user interface (display and buttons) and a cross-platform external application (PC/Android); battery charging with real-time state-of-charge (RSoC) measurement; and an algorithm for estimating remaining operating time. The system was validated under different operating conditions, demonstrating an RSoC measurement accuracy above 98% and enabling wireless communication for real-time data visualization. This board will facilitate the rapid development of portable prototypes in medical, IoT, and embedded system applications.