Design Of IOT Smart Gateway Based On ARM9

Industrial production is an important aspect of the country’s energy and resources use. Energy and resources monitoring and planning is of great significance during industrial production process. Varies kinds of energy and resources are used in modern industrial plants, including electricity, water(tap water, intermediate water), heat(steam, condensate water), air(compressed air, nitrogen, argon, oxygen, propane, etc.), gas, oil, solid fuel, etc. In modern energy and resources management system, the amount of energy and resources is measured, transferred to and stored in information management center. Data is monitored and analyzed in information center making it easier for management staff to take control of the data and its trend in every measurement point.Base on the background of industrial energy and resources measurement and monitoring, a smart industrial gateway device is designed using ARM and Linux. Data acquisition of meters using various protocols is implemented with local storage and remote transfer enabled. Seven serial ports are implemented via pin multiplexing on AT91SAM9G20. Half-duplex RS485bus is enabled using SP485EE with effective signal and power isolation. In Ethernet part, EMAC module in the microcontroller is used and connected to DM9161via RMII interface, thus, realized100Base-T full duplex Ethernet transfer. The design is discussed in three parts:circuit design, OS design and application software design.The design of microcontroller, power supply, calendar, memory, sound card, net card, RS485interface, USB interface and SD card slot is described in detail. PCB routing and debug methods are introduced briefly.In the OS part, Linux is used as OS kernel and U-Boot is used as boot loader. Some of the driver codes are modified catering to the demand of the application. Basic utilities are build using busybox and written into flash memory as the root file systems in UBI format.Application software is written in Go programming language. It implemented three major protocols used in industrial meters. Communication between server and gateway device is via TCP/IP and HTTP protocol and data transfer is realized according to regulations defined by national standards.In the last part of the article, tests made about functionalities of the device is described briefly and further extensions and tests are expected.