Overview

Consisting of three individual boards, each with a specific function, the CUBE project's components are connected using high-speed connectors, alongside a battery and casing. When fully assembled, the product measures a compact three cubic centimeters.

The first board, situated at the bottom, is the power board, featuring a USB-C connector for battery charging and communication to the main chip, along with a 3.3V buck regulator, Li-Po charger, and a BGA-packaged fuel gauge. Temperature sensors on the board's underside monitor battery temperature, presenting power design and BGA package usage.

The second board, located in the middle, houses an ESP32-S2 with an antenna for WiFi and Bluetooth capabilities, showcasing proper MCU placement and routing with double-sided assembly practices.

The third board, positioned on top, is the sensor board, equipped with RGB LEDs, temperature/humidity, accelerometer/gyroscope sensors, and a ToF sensor, demonstrating proper I2C communication standards and isolating critical sensors like the temperature/humidity sensor.

The casing is simplistic and features cutouts at the connectors and buttons.

This project was completed using Altium Designer, with FreeCAD utilized for the casing. The Altium Designer multiboard feature was used to ensure that all boards align perfectly.

You can find this project on GitHub!