Design of Farmland Information Intelligent Collection Node Based on GPS

Transcription

1 Design of Farmland Information Intelligent Collection Node Based on GPS Yue Liu 1, LiGuo Tian 2, Meng Li 2, and ZhiLiang Chen 2 1 Tianjin Modern Vocational Technology College, Tianjin, China, Tianjin Keylaboratory of Information Sensing&Intelligent Control, Tianjin University of Technology and Education, Tianjin, China {liuyue201202,tlg1234}@163.com Abstract. Timely and accurate acquisition of the farmland information is the foundation of the implementation of precision agriculture. Farmland information acquisition technology based on the GPS is an important means of precision agriculture information acquisition. According to the characteristics of field information collection, such as high density, high accuracy, low cost and so on, it designed intelligent farmland information acquisition node based on GPS. The node with the portable GPS positioning module, used the embedded processor STM32F103VC as the core, integrated the farmland information acquisition sensor, could acquire, process and transmit temperature and humidity in the field information, so as to realize to monitor the farmland information parameter in the long distance. After tested, the node works well and has achieved the design requirements. Keywords: Precision agriculture, Information acquisition, GPS positioningm, Intelligent node, Humiture sensor. 1 Introduction Precision agriculture is a rising and interdisciplinary synthesis technology developed in the international agriculture field at the early 1980s [1], it is an important modern agriculture form developed on the basis of the modern information technology, biotechnology, engineering technology and a series of high and new technology, provided with some characteristics, such as the reasonable use of agricultural resources, increase of crop yield, lower production costs, improvement of the ecological environment [2]. Farmland information collection technology plays an important role in the implementation of precision agriculture. Application of the low cost, high efficient intelligent equipment in farmland information collection to get temperature, humidity, light and CO 2 concentration which could affect the crop growth and soil moisture and other real-time dynamic microenvironment information based on precise space position can better advance the implementation of precision agriculture. On the basis of characteristics of farmland information data acquisition, the paper designed a farmland information intelligence collection node based on GPS, D. Jin and S. Lin (Eds.): Advances in CSIE, Vol. 2, AISC 169, pp springerlink.com Springer-Verlag Berlin Heidelberg 2012

2 294 Y. Liu et al. which can better acquire temperature and humidity parameters in the farmland microenvironment information and implement the corresponding data display, storage and transmission, thus, provide the farmland information data support for implementation of precision agriculture. 2 Application of GPS Technology in the Farmland Information Acquisition GPS (Global Positioning System) is the English abbreviation of navigation satellite timing and Ranging/global positioning system, referred to as the" global positioning system". The system which is a satellite-based radio navigation and positioning system, has totipotency(land, sea and aerospace), global, all-weather, continuous and real-time navigation, positioning and timing function, provides all types of users with precise three-dimensional coordinates, speed and time [3]. In order to increase the soil utilization rate to the hilt, Precision agriculture technology based on the geographical coordinates is to manage various measures effectively in crop production (fertilizer, seeds and pesticides) according to the soil characteristics and crop physiological state, optimize the crop production, so as to achieve the minimal resource consumption and environmental pollution, maximize economic benefits, and make agriculture develop sustainably. GPS equipment can provide the accurate information of spatial position. On the basis of the combination of GPS technology and farmland information acquisition technology, in the acquisition of farmland information, spatial location information could be acquired synchronously at the same time, thus dynamic microenvironment information for each spatial position could be obtained in real time, which could provide data support for the precision agriculture [4]. 3 Overall Design of System Farmland information collection of precision agriculture mainly obtains crop growth microenvironment information, including humiture, illumination, CO 2 concentration and soil moisture, which are important for crop growth. According to those above information, the paper designed the farmland information intelligent acquisition node based on GPS, the node used the embedded processor STM32F103VC as the core, collocated with the portable GPS positioning module, Nokia5510 LCD module, humiture sensor module, ZigBee wireless transmission module and SD card data storage module, can be used alone for data acquisition, processing and display as well as constitutes wireless sensor network together with the ZigBee module and the other node for field information data collection. The general diagram of the node is shown in Fig.1.

3 Design of Farmland Information Intelligent Collection Node Based on GPS Hardware System The hardware system of the farmland information intelligent acquisition node mainly comprises a microprocessor module, GPS positioning module, humiture sensor module, LCD display module, wireless transmission module and power supply module. Fig. 1. The system overall block diagram 4.1 Microprocessor Module The microcontroller adopts 32-bit processor STM32F103VC used ARM Cortex-M3 as core, its working frequency is 72MHz, built-in high-speed memory (high 128K byte flash and 20K byte SRAM); it has a wealth of enhanced I/O port and peripheral connected to the two APB bus; contains two 12-bit ADC, three general 16-bit timer and a PWM timer, also contains a standard and advanced communication interfaces: up to 2 I 2 C and SPI, 3 USART, one USB and one CAN [5]. 4.2 GPS Positioning Module GPS positioning module use the global satellite positioning receiving chip GS-89m-J which belongs to the Gstar series. GS-89m-J is a high performance, low-power consumption intelligent satellite receiver module, which is the third generation satellite positioning receiving module made by the United States Rifi company as well as a complete satellite positioning receiver. The module takes a digital /analog separate-design method, which effectively improves the anti-interference ability; besides, it has 32-channel capture engine, maximum update rate is 1s, accuracy range is less than 10 meters. The module connect with the microprocessor through the serial interface, the GPS data receiving circuit as shown in Fig. 2.

4 296 Y. Liu et al. 4.3 Humiture Sensor Module SHT71 is a high-integrated chip which integrates many functions such as temperature sensing, humidity sensing and signal conversion, A/D conversion and heater, and output the digital signal. The SHT71 has high antijamming capability, higher cost performance and lower power dissipation; additional, all the technical index of the SHT71 is identical to the design requirement. Fig. 2. GPS data receiving circuit 4.4 LCD Module LCD module using Nokia3310 LCD, can display English characters and Chinese and graphics. The control driver of LCD is PCD8544. PCD8544 is a low-power consumption CMOS LCD control driver, designed to drive the 48 rows and 84 columns of the graphical display, all the necessary display function are integrated on a chip, including LCD voltage and the bias voltage generator, only need a few external components and small power consumption. 4.5 ZigBee Wireless Transmission Module Wireless transmission module is mainly used for data transmission when the node constitutes wireless sensor network with other nodes, here ZigBee technology is adopted. The chip used the second generation of ZigBee /IEEE RF SoC of TI Company CC2530, which is mainly used for 2.4 GHz free-license ISM band. CC2530 integrates enhanced 8051 microcontroller core, 2.4GHz RF radio transceiver in accordance with the IEEE standard and the 256k Flash program memory, supports the newest ZigBee2007pro protocol stack, equips with two powerful USART with support for multi-group serial protocol, one MAC timer in accordance with IEEE , one 16-bit timer, and two 8-bit timer.

5 Design of Farmland Information Intelligent Collection Node Based on GPS Software System The software system of the farmland information intelligent collection node includes a board-level initialization procedure, driver, embedded operating system and applications, these parts combined together organically form specific integration software system. The bottom-up software architecture of the node includes: driver layer, operating system layer and application layer, software architecture as shown in Fig. 3. Fig. 3. The structure chart of the software architecture 5.1 The Imbedded Operating System μ COS-II is a real-time and be-deprived kernel of operating system. The operating system supports up to 64 tasks, but every task s priority should be different each other; the task provided with small priority number has higher priority than the task provided with large priority number, also, the system always dispatches the ready task provided with the highest priority to run. 5.2 Task Management and Communication of μcos-ii A task is in four different conditions, namely, dormancy state, ready state, running state, wait or suspend state. The conversion of the different task status is shown in Fig.4. Once the task is established, it will be in ready state and waiting for running, and when the concurrent events emerge, the task provided with the highest priority will be immediately given the right to CPU, and after the task is finished and suspended or the interrupt service routine is finished, next task provided with the highest priority than others will get the right to use CPU. If the running of system results in that the priority of the task which in the ready state is higher than the priority of the task which in running state, the system will call the scheduling function, so the task which in the running state will lose the occupation of the CPU and return to the ready state, however, the task in ready state which has the highest priority will be turned to the running state.

6 298 Y. Liu et al. Fig. 4. Tasks state transition diagram 6 Conclusion During the course of the implementation of precision agriculture, farmland information collection technology is indispensable and important. Application of low cost, high-efficient intelligent equipment in farmland information collection and the use of information technology to promote and transform traditional agriculture could push forward Chinese traditional agriculture to develop towards precision agriculture steady and rapidly. Acknowledgments. The authors thank all the people who had given helps to them in the work. This work is supported by Tianjin University Science & Technology Fund (Grant No ). References 1. Wang, M.: Development of Precision Agriculture and Innovation of Engineering Technology. Agricultural Engineering Journal 15, 1 8 (1999) 2. Liu, A., Feng, Z., Xu, L.: Modern Precision Agriculture and Development of Precision Agriculture in China. Journal of China Agricultural University 5, (2000) 3. Liu, J.: GPS Satellite Navigation Positioning Principle and Method. Science Press, Beijing (2008) 4. He, Y., Fang, H.: Research on Precision Agriculture Information Processing System Based on GPS and GIS. Journal of Agricultural Engineering 18, (2002) 5. Li, N.: Application Development of STM32 Processor Based on MDK. Beijing University of Aeronautics and Astronautics Press, Beijing (2008) 6. Shao, B.: Embedded Real-time Operating System μc/os-ii, 2nd edn. Beijing University of Aeronautics and Astronautics Press, Beijing (2003)