This project reports the design and validation of a wheeled mobile robot that collects spatially distributed environmental data inside a building. Built on the four-board GEMS stack—Sapphire (communication), Ruby (sensing), Diamond (motor control), and Emerald (power), the prototype integrates a CAN bus backbone, an I2C sensor backplane, ultrasonic obstacle detection, and a Wi-Fi web interface. Responsibilities were divided among three subgroups. The wireless team implemented the CAN network, web server, and finite-state machine for autonomous navigation. The mechanical team designed and printed the chassis; they also developed battery management and voltage regulation. The motor control group implemented the PI control. Integration tests show that the system satisfies every “must-have” requirement in the Programme of Requirements: CAN frame loss remained below 1 % during a five-minute run, Wi-Fi throughput exceeded 1 Mbps in the range of ten meters, ultrasonic sensors detected obstacles from 10 cm to 30 cm and temperature and humidity data were logged at 2 Hz with millisecond precision. However, late delivery of prefabricated cabling forced a temporary hand-wired CAN harness, leaving room for mechanical refinement. Overall, the project demonstrates that the open-source GEMS [10] architecture can be turned into a low-cost, modular sensor platform on wheels, providing a reproducible foundation for future research and classroom exercises in embedded communication, control and data acquisition.