The Design Of WSN Gateway Based On Cortex-M3

Along with the development of Internet of Things, the connection of wireless sensor network and Internet has become the inevitable trend. The two kinds of networks use different communication protocols, so in order to achieve seamless connection between them the gateway plays a very key role. Wireless Sensor Network Gateway is the most important part of the wireless sensor networks. It is a transit point when the Wireless Sensor Networks connect to the wired devices. It can send commands, forward data, choose routing, convert protocol and so on. So the design and implementation of Wireless Sensor Network Gateway plays a vital role in the popularity of the Internet of Things. This paper introduces the design of a Wireless Sensor Network Gateway, in order to resolve the problems of IP access.Based on the deep study of the existing Wireless Sensor Network Gateway, this paper put forward a kind of compatible multiple WSN protocol gateway. It mainly achieves three ways of IP network access, including Ethernet access, RS-485 bus network access and public wireless IP network access. This article describes a method of hardware realization plan of the connection of IP network and WSN from the aspect of hardware. Based on the analysis the function of each module, the key hardware modules interface was designed. The key modules mainly include ZigBee wireless transmission module, the Ethernet interface module, RS-485 bus interface module, public wireless IP network interface module and the SDRAM module. This paper designed a multi-protocol gateway. This gateway uses the Cortex-M3 as the processor and combines the 802.15.4 MAC processor of the SoC (System on Chip) and run the WSN protocol stack on it, realized the communication between IP network and WSN network and finished the function of protocol conversion between the wire and wireless network. Compare with the existing Wireless Sensor Network Gateway, the scheme can enlarge the range of wireless access gateway in a lower cost.Finally the paper discusses the hardware test programs on the gateway and gives the test and analysis of the system. It proves to achieve the expectation and be feasible for the system.