Context - The Internet of Things (IoT) refers to a distributed network of smart, connected devices that collaboratively sense, process, and act upon real-world environments. Designing such systems requires managing complex architectural concerns spanning software logic, hardware configuration, and spatial deployment, as well as validating non-functional properties like energy consumption and communication efficiency. Objective - To provide a unified, architecture-centric framework that supports the description, simulation, and automated code generation of IoT applications across software, hardware, and physical space dimensions. Method - We use Model Driven Engineering(MDE) approaches to develop CAPS, a framework that uniquely integrates multi-view architectural modeling, energy- and traffic-aware simulation via CupCarbon, and seamless generation of deployable Arduinocode from high-level design models. Result - CAPS enables a traceable and cohesive development process from architectural design to physical deployment. Case studies from diverse domains demonstrate its ability to improve modeling expressiveness, maintain transformation fidelity, andreduce development time through automation. Conclusion - CAPS unifies architectural modeling, simulation, and code generation into a novel, end-to-end toolchain, addressing fragmentation in the IoT development lifecycle and enhancing early validation and traceability.