The Development And Application Of The Granary Temperature Measure System

With the development of wireless communication, microelectronics, embedded and sensor technology, especially the internet, it becomes possible to design the lower cost and advanced measure method of granary temperature.A kind of granary temperature measure system based on embedded WEB Server, and combined with wireless , embedded and network technology is designed in this paper.The embedded WEB server is the Master Controller of the system; its control chip is LPC2468 ARM Microprocessor that incorporates many peripherals such as Ethernet Media Access controller and SD/MMC memory card interface. The Master Controller gets together with Wireless Data transmission module, and implements wireless communication. Its software adopt the RTX real time operation system of Keil RMDK as the platform, build the embedded WEB server, and multi-task switch, real time control and measure, remote update via internet can be realized.Temperature Measure Controller is the data collection terminal of the system, and it is based on the digital temperature sensor DS18B20. LPC932A MCU is the control chip of the Temperature Measure Controller, and it control the DS2482-800(1-Wire bus to I2C bus transition chip) via the I2C bus, then send the temperature measure command and call back the temperature has been measured. Extraordinary the method of how to enhance the driver capability of the 1-Wire bus was introduced.Wireless data module SWRF-508 is integrated in the Sub Controller .The Sub Controller receives measure command form Master controller, and send back the temperature values that given by Temperature Measure Controller. RS485 Bus communication mode was adopted between the Sub Controller and the Temperature Measure Controller.Users access Embedded Server by Internet browser to get loca1e and history Data expedient1y. Administrators can add or delete accounts and modify or set information of granary and Parameters of Embedded server.