Smart home system with four-layer architecture: sensors (temperature, gas, motion, distance, push button) feed into Arduino Uno R3 microcontroller, which processes inputs and communicates bidirectionally with a cloud server via internet connectivity. The controller layer manages real-time actuation of servo door motors, DC fans, LED lights, and displays, while a smartphone app provides remote monitoring and control through the cloud server. This layered design separates sensing, control, cloud integration, and actuation for scalable, maintainable home automation. Fork and customize this diagram on Diagrams.so to prototype your own IoT system or integrate additional sensors and actuators. The Arduino Uno R3 acts as the intelligent hub, enabling both local automation logic and cloud-based remote access patterns.