Development of a plant monitoring system for greenhouse management
Hong Feng Sun, Hong Feng Sun, Minzan Li, Lixuan Wu, Lihua Zheng, Wei Yang · 2014 ASABE Annual International Meeting · 2014
Abstract. In order to acquire the crop growth information non-destructively, a crop monitoring system was designed based on the spectrum and wireless sensor network (WSN) technology. There are three parts including an optical measuring unit, a network coordinator and data management software. The optical measuring unit is used to measure the spectral reflectance of crop canopy with four channels at 550, 650, 766 and 850 nm separately. A silicon photodiode is used to convert the light signal to current signal in each optical channel. The signals are then amplified and transformed to voltage signals, and subsequently read through A/D convertors in the microcontroller unit (MCU). A JN5139 wireless module (Jennic Co UK) was applied as the core element of the optical measuring unit. It provides all RF components and various peripherals, and gives a comprehensive solution with high radio performance. A JN5139 microcontroller as MCU was integrated in that module to implement IEEE802.15.4 or ZigBee compliant systems. The measured data are wireless transmitted to the coordinator via antenna using ZigBee protocol. As the coordinator of the wireless network, the network coordinator was developed based on a WIFI module. It is used to build and organize the local area network (LAN) and to receive all the data from the optical measuring unit. And then the information is transmitted to a data server. The data management software was developed to process, analyze and display the received data. The calibration tests verified the stability of the wireless network and the measurement precision of the optical measuring unit. It is indicated that the crop monitoring system provides a support for crop monitoring in the greenhouse.