Recently, one of the main research topics in the context of application of Cyber-Physical System (CPS) in the Smart City and Industry 4.0 scenarios is the one related to the use of Robot Operating System (ROS)-based CPS. Specifically, one of the main interest is to allow a ROS-based smart robot needs to communicate with other heterogeneous Internet of Things (IoT) applications in an intelligent environment to efficiently react to the system requirements and environment changes. However, the communication between the IoT systems will face many challenges and increase the cost and risks that lead to the requirement of a cross-platform communication for bridging the ROS-based CPS and other heterogeneous IoT applications. This paper introduces an OSGi-based adaptor, named the ROS Edge Node, for the interoperability between Robotics domain and other IoT domains, leveraging the highly modular BRAIN-IoT federation, which allows to decentralize, composite and dynamically federate the heterogeneous IoT platforms by leveraging OSGi. Together with the unfixed infrastructure of BRAIN-IoT solution, the event-driven asynchronous communication mechanism realizes cross-platform interaction with ROS-based CPS and solves the major challenges faced. The ROS Edge Node is packaged as a BRAIN-IoT Service with Requirement/Capability in metadata, similar to microservice, to be deployed in a distributed BRAIN-IoT Fabric cluster as a bridge between the underlying ROS-based robotics systems and other OSGi-based IoT systems in various IoT domains via an Asynchronous Eventing Substrate (BRAIN-IoT EventBus). This paper demonstrates the solution developed in an service robotics use case in a warehouse to show how the OSGi-based adaptor enables the fast adaptivity and interoperability between heterogeneous IoT domains in a federated environment.