The Design And Development Of General Smart Home System Based On MQTT

The evolving intelligence of household appliances enables them to sense the environment through sensors and create better user experiences. At the same time, with the proliferation of the Internet and the improving performance of smartphones, smartphones have become the main terminal devices that peoples use to connect to the network. Besides,dueing to the sustainable development of the Internet of Things, household appliances can also connect to Internet, so that smartphones can check the device status and send control commands at any time through the Internet. However, the current software in the market are all binded to a specific kind of household appliances, thus it requires multiple mobile applications to control multiple appliances. Therefore, If we design a general system integrating different appliances’ infomation and provide unified management by one mobile application, the users‘ experience will improve significantly and the smart home will become more pervasive.Under this requirement and technique background, we design and implement a general smart home management system based on MQTT to integrate heterogeneous hardware and information, and develop a mobile application that can display and control the appliances. This system is composed of three parts, a gateway based on Raspberry Pi, a server based on Openwrt and a control end based on i OS application. We solve the heterogeneity of hardware by adding a gateway between the appliances and the server to connect varing appliances which use diverse network communication protocols, and normalizing the device information to transmit data to the server.By adopting meta-programming approach to abstract the devices and their properties respectively, the scalability of the system is improved significantly. Meanwhile, the abstract data of the devices and their properties provide the basis of unified display, which means that the data can be mapped directly to UI widgets of UIKit,thus we can conveniently add a new device or property data onto the widgets through prepared matching patterns instead of code. With the general scheme for managing heterogeneous hardwares and information, our system provides a management paltform that can be applied to most of household appliances. Dueing to the restricted computing resources of the embedded devices that our system is mostly composed of, our system employs MQTT protocol to transmit information for its little demand for memory and CPU.In order to verify the feasibility and reliability of the system, we use black-box testing method to test the functional modules of our system.Besides, we measure and compare the performance of the sytem based on MQTT with it based on persistent HTTP connection from three aspects, the memory usage,the CPU usage and energy consumption, etc. The results show that the system based on MQTT outperforms another one from all three aspects and meets the design requirments.