Development Of A ZigBee-based Wireless Sensor Network Prototype

With development and application of wireless sensor networks (WSNs), WSNs have been widely studied. A prototype system for WSNs has been designed and developed with technologies of ZigBee and GPRS. The hardware of this system consists of a WSN system and a gateway. The WSN system is developed based on the system on chip (SoC) introduced by TI, which is also known as TI CC2530. The gateway transfers information via GPRS between the ZigBee-based WSN system, Internet and the back-end controller. The software for ZigBee routers, coordinators and front-end devices is developed on TI Z-Stack protocol stack. Functions of software include gathering, processing and uploading data. More details are described as follows:1. Hardware design:RF circuits, sensor modules and peripheral ciruits of ZigBee nodes; the gateway based on a STC51microcontroller, a ZigBee module and an MG323GPRS module.2. Transplation of the Z-Stack protocol stack:According to requirements and specifications of the developed WSN system, the Z-Stack protocol stack is tailored and transplanted so as to be implemented correctly.And Completed development of coordinator’s serial data handler, ZigBee sensor network sensor-driven programme.3. Embedded software designed for the gateway:In order to transmit information from a ZigBee node to the back-end server through a gateway, a serial port protocol and a unified data structure are developed. A reliable transmission mechanism is applied so as to achieve error control and retransmission, In addition, a priority procedure is applied so as to achieve higher priorities for more important messages, and alarm in time.The study is completed in Enjoyor Corporation. With various sensors, this system may be applied in many areas, such as industrial control, environmental monitoring, and smart home.