Communication for UAV Swarms: an Open-source, Low-cost Solution Based on ESP-NOW

Multi-UAV systems typically require complex in-frastructure to deploy in real-world scenarios, limiting their accessibility and scalability. In addition, current research often relies on custom solutions or proprietary hardware to facilitate inter-UAV communication. In this paper, we propose an open-source, low-cost, plug-and-play solution to enable decentralized UAV-to-UAV communication over 2.4GHz Wi-Fi using a con-nectionless protocol. Our approach simplifies the deployment of decentralized systems by allowing UAVs to easily exchange any type of binary data, seamlessly interfacing with ROS2. The solution uses an ad-hoc style network that allows UAVs to join or leave dynamically without requiring centralized governance or a priori configuration. We describe the architecture of the system, assess the network performance in an outdoor environment using UAVs, and evaluate the system's ability to share information as a swarm through hardware-in-the-loop (HITL) and experiments using UAVs. Our results show that the proposed system facilitates connectivity and is able to transmit mission-critical data for real-world UAV operations. HITL experiments show that a decentralized planning algorithm running on three simulated UAVs can effectively reach consensus on decentralized task allocation. We have made the code public and thus provide a viable solution for researchers seeking to implement decentralized UAV swarms using cost-effective commercial-off-the-shelf (COTS) hardware and minimal infrastructure.