1、1The Design of Agricultural Intelligent Irrigation System based on CC2430Abstract. The intelligent irrigation system can achieve precision irrigation， that is an effective way for the sustainable development of agriculture in arid area. In this paper， using the CC2430， intelligent irrigation system
2、was designed and implemented according to the actual needs of the decision-making and management of plant irrigation. Distribution of soil temperature and humidity monitoring the system to solve the difficult and critical hardware products import prices too high and difficult to promote. The system
3、cost compared to similar foreign products decreased 44.8%. Compared with traditional irrigation methods， crop water use efficiency of 22.6%. Key words： smart irrigation system， CC2430， ZigBee 1. Introduction Water shortage is a bottleneck restricting the development of arid zone agriculture， and pre
4、cision irrigation is an effective way to achieve the sustainable development of dryland agriculture. With the situation growing shortage of water 2resources in China， the increasingly widespread application of information technology in the field of agriculture 1， research and promote the use of inte
5、lligent water-saving irrigation will be an important direction for future agricultural development in arid areas. Internet of things is called the second computer， Internet， 3rd wave of the information industry， the rapid development and application. Things technology， also called sensor network tec
6、hnology， it is a combination of sensor technology， embedded technology， distributed information processing technology， modern networking and wireless communications technologies， sensing devices of all kinds of information and the Internet combine to form a huge network， all items （equipment） are co
7、nnected to the network with intelligent identification and management 2. Things technology has been applied in modern agriculture 3-4. In recent years， irrigation techniques applied in dry places large area. With the advances in irrigation technology gradually extend and automatic measurement and co
8、ntrol technology， sensor technology， information technology， intelligent irrigation technology came into being， the domestic and foreign research. In this paper， the ZigBee 3wireless communication technology-based research arid zone intelligent irrigation key technologies， in order to improve the di
9、agnostic accuracy of the irrigation water deficit， intelligent level and irrigation water use efficiency. 2. System Design 2.1 ZigBee technology ZigBee technology is a short-range， low-complexity， low-power， low-data-rate， low-cost wireless communication technology， using the 2.4 GHz band， using fre
10、quency-hopping technology， in line with the IEEE802.15.4 protocol 9. The main features of the technology： 1） The data transfer rate is low； 2） in the low-power standby mode， two ordinary No. 5 dry cell can be used from 6 months to 2 years； 3） protocol， and waive royalties can greatly reduced cost； 4
11、） network capacity， each ZigBee network can support up to 255 devices； 5） 10 5 000 m， based on the transmission power of the size and variety of application modes may be effective coverage； 6） The use of the frequency band of 2.4 GHz， 868 MHz （Europe） and 915 MHz （USA） ， are unlicensed band. IEEE802
12、.15.4 agreement there are three types： a star structure， mesh structure and a cluster structure in the network topology， wherein the mesh structure and the cluster structure belonging to a point-to-point structure of. Devices 4with communication functions can be divided into full-function device （FF
13、D） and Reduced Function device （RFD）. FFD devices， FFD device and RFD devices can communicate directly， RFD devices can not communicate directly. IEEE 802.15.4 network， FFD device， a network coordinator is main controller sensor networks. Each network is only one master controller. Network coordinat
14、ion the addition directly involved in the application， but also completed as a member of management， link status， information management， and packet forwarding function. 2.2 System structure The system consists of： a management center station， an automatic weather station， a first control station， f
15、our soil moisture monitoring points， 12 micro-irrigation CPU （remote terminal unit， remote control unit） control points. Characteristics and size distribution according to the site of the demonstration area monitoring and control system uses ZigBee star network structure of the communication network
16、 design， the overall system structure shown in Figure 1 below. The relay station as a coordinator in a star network structure， soil moisture monitoring point， the solenoid valve control point and management center station responsible for the 5communication link is established to ensure effective smo
17、oth channel. Comparative Test by domestic and foreign soil moisture sensor site analysis， screening out produced by Nantong transit， soil moisture sensor MP406 sensor 10 as a demonstration zone soil moisture monitoring point. MP-406 is constituted by the circuit board and the stainless steel probe a
18、ssembly. The circuit board is enclosed in ABS waterproof indoor stainless steel needle is inserted into the soil measurement. The tail of the probe cable to enter a suitable operating voltage and the output signal detected. Measurement area： 90% of the impact of the cylinder around a central probe d
19、iameter of 2.5cm， the length of 6cm， measurement accuracy： 2%. 2.3 The laying program of water pipes Soil moisture monitoring regional area is 20m 15m； 12 irrigation control points， respectively， laid in the field support tube at each irrigation CPU control two electromagnetic valve of switching act
20、ion and collecting electromagnetic valve switch state signal； relay station laid in the 2nd irrigation CPU controlpoint forward central station instruction and field electromagnetic valve control point； automatic weather station weather data sent to the management center station through 6wired commu
21、nication （RS-485） ； first control station for inverter control pumping stations， throughmanage ZigBee receive the instructions of the central station， the implementation of the precise control of the water supply movements and traffic. The distance of the field sites： the central station to the rela
22、y station， a distance of about 600 m relay stations to 12 irrigation CPU control point distance of about 600 m， the central station is about 1 000 m distance to the pumping station. According to the distance of the site of the field， irrigation CPU using a low-power ZigBee module， the communication
23、radius of about 300 m； relay station and the central station is in power ZigBee module， the communication radius of about 1 200 m. Soil moisture sensor is installed in accordance with the 20m * 15m rectangular four corners. 3. Control module design The control module is the implementation of key par
24、ts of the decision-making system of intelligent irrigation， low-cost， low-power consumption are its main features. In order to reduce the CPU cost of irrigation， increased versatility， so that it can be applied to different geographical environment， suitable for the needs of the different means of c
25、ommunication， using the master-slave structure， modular 7design. CPU hardware structure shown in Figure 3. Irrigation CPU board using CC2430 microcontroller （MCU） to design， including the power circuit， AD sampling circuit and solenoid valve control circuit； embedded module board design including co
26、mmunication circuit from the board， motherboard interface for serial （RS232） ， GPRS / CDMA， 3G， GSM， ZigBee， FM radio and other means of communication， to meet the optimal way of communication for communication network design can be chosen depending on the applications. The system board with ZigBee
27、communication module. 4. The design of intelligent irrigation decision-making system 4.1 Software Design The first layer is a man-machine interface layer， the functional interface of the different levels of the main design users， domain experts and database administrators and software system. The gr
28、aphical user interface （Graphical the User Interface GUI） technology， from the personality input， output devices. Designed with easy touchscreen devices daily advice for the novice user to use， user remote consultation use WEB interface using a PC， use the LAN software interface advanced users， know
29、ledge engineers and database 8administrators to manage the maintenance and use. The second layer is the internal interface layer of the functional components. Software components after use building blocks to achieve the various functions. The third layer is the database layer， centralized database a
30、ccess and distributed database access method is selected according to user needs. The main function of the system include 4 parts： information management， real-time decision-making， production management and expert reasoning. The system topology uses B / S structure， development environment VistualS
31、tudio.NET + Ajax + Visual C + +， Oracle 9i database. C #. NET development server side functionality， the use of C + + component development component of the professional program. 4.2 Moisture control threshold Reference 1 Yang Wei， Li Minzan， Wang Xiu. Status quo and progress of data transmission an
32、d communication technology in field information acquisitionJ. Transactions of the Chinese Society of Agricultural Engineering， 2008， 24（5）： 297-301. 2 Bao Changchun， Shi Ruizhen， Ma Yuquan， et al. Design and realization of measuring and controlling system based on 9ZigBee technology in agricultural
33、facilitiesJ. Transactions of the Chinese Society of Agricultural Engineering， 2007，23（8）： 160-163. 3 Yang Fengliang， Jiao Xiyun， Liu Yixiu， et al. Layout of soil moisture monitoring points for cotton mulched drip irrigationJ. Journal of Irrigation and Drainage， 2010， 29（3）：29-31. 4 Wang Shufang， Jiao Xiyun， Wang Weihan， et al. Spatial and temporal variability of soil moisture under mulched drip irrigationJ. Journal of Irrigation and Drainage， 2009，28（5）： 34-37.
