African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6576

Full Length Research Paper

Design of wireless underground sensor network nodes for field information acquisition

Zenglin Zhang1,3, Pute Wu1,2,3*, Wenting Han1,2,3 and Xiaoqing Yu1,3
  1Northwest Agriculture and Forestry University, Shaanxi, Yangling, 712100, China. 2National Engineering Research Center for Water Saving Irrigation at Yangling, Institute of Soil and Water Conservation of Chinese Academy of Sciences, Shaanxi, Yangling, 712100, China. 3Research Institute of Water-saving Agriculture of Arid Regions of China, Shaanxi, Yangling, 712100, China.
Email: [email protected] or [email protected]

  •  Accepted: 16 December 2011
  •  Published: 31 January 2012

Abstract

 

With the research of the wireless sensor network technology, some wireless underground sensor network nodes and a sink node based on embedded technology and RF technology were designed innovatively. Wireless underground sensor network node consists of sensor, the processor, wireless RF module and power module; here, processor using MSP430 microcontroller, RF modules adopting nRF905 communication module and having 433/868/915 MHz 3 ISM channel. Moreover, the sink node is made up of RF transceiver module, the core control circuit, information processing, data storage, Liquid Crystal Displays (LCD) module and power supply. The nodes which acquired soil parameters information were regularly distributed in the monitoring area. The sink node collected the information of nodes that were sent in way of a single jumping or multiple hops and implemented fusion, analysis, processing, storage and display of information. For 50% sands, 35%silt, and 15% clay, a bulk density of 1.5 g/cm3 and a specific density of 2.6 /cm3, test is conducted for different soil moisture (5, 10, 15, 20 and 25%) in three different frequencies 433/868/915 MHz, result shows that radio signal path loss is the minimum in the low frequency and low moisture. Furthermore, the changes of node deployed depth (0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8 and 2 m) affected signal attenuation under 433 MHz, it is concluded as the best wireless underground sensor networks (WUSN) node buried depth for effective transmission.

 

Key words: Wireless underground sensor networks (WUSN), sink node, MSP430, soil moisture, depth,information acquisition.