Implementation of agricultural sensor network systems based on Arduino based microcomputer board with Bluetooth Low Energy

摘要

A sensor network in agricultural fields is a new technology to increase agricultural productivity by measuring important factors for plants such as air temperature, humidity, illumination intensity, soil moisture, soil temperature etc. The authors have been studied about some wireless sensor network systems, and have found that general microcomputer boards do not have enough performance to realize accurate measurements and stable wireless communication because they just consider the stable operation of their own electronic components, and do not assume practical external sensors and wireless communication modules. Therefore, a special design of microcomputer boards for sensor networks is required to develop practical agricultural sensor network systems. This paper proposes a new type of sensor network system for agricultural usages. The system consists of a new developed microcomputer board, a special smartphone application for data collection, and a data management server. The developed microcomputer board has special functions for a charging function from a solar cell to a lithium polymer battery, a large-current regulator for external electronic components, a capacitor for power supply stability, real-time clock (RTC), a power management for external sensors, a SD card support, and a communication function based on Bluetooth low energy (BLE). The special application supports BLE communication, which is a wireless personal area network technology for low-power communication. It also collects the measurement information from a developed microcomputer board within BLE communication range, and uploads the collected measurement information to the data management server. The benefit of the proposed system is accurate measurements with special external sensors for agricultural usages, and the easy installation of the microcomputer board by the autonomous operation and the easy data collection with the smartphone application.