Arquitetura de gateway LoRa integrada ao ROS 2 utilizando FreeRTOS

Abstract

The expansion of mobile robotics to remote areas requires long-range communication. The ROS 2 middleware (via DDS) generates excessive multicast traffic, saturating low-bandwidth networks like LoRa. This work presents the development and experimental validation of a gateway architecture integrating ROS 2 and LoRa via a deterministic FreeRTOS firmware, named ROS2_LR_Protocol, implemented on the Heltec WiFi LoRa 32 (V2) hardware and validated with an iRobot Roomba in an outdoor environment. The firmware manages three concurrent tasks (radio, micro-ROS, and monitoring), protected by an SPI Mutex, using compact 21-byte packets (CRC-16) and a drop-old strategy to prevent buffer bloat. In the field, average latency was 118 ms at 100 m (SF7) and 2705 ms at 500 m (SF12), reflecting the intrinsic trade-off of CSS modulation. The system remained stable up to 500 m in NLOS environments, significantly outperforming Wi-Fi range. The architecture validates a viable, low-cost, and highly replicable Commercial Off-The-Shelf (COTS) solution for connected robotics in areas lacking network coverage.