Design and Implementation of ZigBee Based Low-Power Wireless Sensor and Actuator Network (WSAN) for Automation of Urban Garden Irrigation Systems

The implementation of automated micro-irrigation in urban gardens using wireless sensor and actuator networks (WSAN) is being more popular. However, the use of WSAN in automated irrigation brings various technical challenges, for example, achieving low cost, long life battery, adequate communication range and compactness. In this paper, a WSAN is designed and implemented for controlling drip irrigation of urban garden that can achieve long battery life, low cost, compactness with the sufficient range of communication. The designed WSAN consists of end-devices and a coordinator, each of which is fitted with single-chip microcontroller along with wireless transceiver. Each end-device is equipped with a microcontroller, a water valve, a soil moisture sensor, a temperature sensor, a rain sensor, battery charger through solar panel and a ZigBee transceiver. The end-device reads the garden temperature, soil moisture level, battery charge status and rain presence and controls the water valve based on these data values. At the same time, the read data is transmitted to the coordinator station through ZigBee ad-hoc network. The coordinator receives the data from each end-device and presents to the interfaced user application. Due to being powered up by an energy limited resource, special techniques and algorithms are developed and only low-power electronic components are selected carefully. This paper includes implemented hardware and software results for the wireless nodes.