This paper presents a building automation system based on the Arduino hardware and Android software. The system supports various sensor functions with a very practical and low cost system configuration. Android blocks that control the Arduino components and sensors are developed with MIT App Inventor 2 software. Additionally, all Arduino components and sensors are put into an unique demonstration model with the purpose of test of the system and the presentation in real-time. With this model, smart building environment is animated and correspondent functions become more understandable. Presented system that supports comprehensive functions has also potential for educational usage and teaching activities due to its practical configuration.