Meteorological Data Acquisition And Processing System Irrigation Based On CAN Bus

In the irrigation management, the optimal water distribution is based on the change of headwater inflow and crop water requirement which is decided by meteorological factors. It usually has bad natural environments and many disperse observation spot in irrigation districts but the data collection has high demand. Currently, the observation facility of irrigation meteorological data is outdated the data transmission is unstable. Therefore, it needs a huge amount of money to maintain the meteorological system, meanwhille, it's difficult to meet the requirements of modern irrigation informatization construction. Hence, it is vital to analyse the meteorological information monitoring demand resulting from irrigation water deployment, research on low-cost irrigation meteorological information collection, develop analysing software and hardware system as well as the development of the corresponding products for irrigation water distribution.Due to the irrigation weather observation station laying in the sparsely populated areas, the wireless data transmission signal is impossible to keep stable and easy to interfere during the transmission process. So the cable communication for data transmission is quite necessary in irrigation. Compared with traditional RS-232 and RS-485 cable communication mode, CAN bus has the following advantages. the main message working ways has higher rate and longer distance; Strong anti-jamming capability, high reliability, high performance-to-price, versatility, the CAN bus communications technology is very suitable for irrigation meteorological data acquisition and the data-transmission processing system. According to the irrigation meteorological data acquisition and processing system characteristic, the CAN bus communication technology was applied to irrigation meteorological elements in the observation and data transmission system. The CAN general module chooses Microchip communication modules for the new MCP2515 CAN controller.This design is composed by several observation nodes, CAN adapter card, PC, and so on. One observation node units includes meteorological data acquisition module, MCU, CAN communication module, mainly complete irrigation meteorological elements of data acquisition, processing, display, data sending such tasks. Use the TI company MSP430F169 microcontroller as the meteorological data acquisition module control chip, Microchip company MCP2515 of CAN controller and CAN receiver controller 82C250 as CAN communication module constitute responsible for completing the sending and receiving data. The CAN adapter card complete the data communications between the can bus and PC. This design using C language on the software design of sensor signal processing, CAN communication modules for sending and receiving messages, the program CAN adapter card design. In addition, PC meteorological data management software is developed by VB6.0. CAN adapter card connected to CAN adapter card. It's real-time display, meteorological data process and storage with irrigation meteorological data collected by Each observation node.The result shows that CAN bus technologies can complete the message data transfer for the single frequency disperse measurement points, low irrigation amount and solve the problems of irrigation meteorological data acquisition, which existis in the irrigation meteorological information observation. The research also shows that CAN communication module is a useful and important tool to transfer weather data.