WSN-based reconfigurable water quality monitoring system in IoT environment

In internet of things (IT) environment, a sensor interface device is essential for data collection in wireless sensor network (WSN) system for water quality monitoring (WQM) as the water pollution is a critical issue globally. This paper presents the design of a WSN based reconfigurable smart sensor interface device for WQM system in an IoT environment. The system consists of Field Programmable Gate Array (FPGA) design board, sensors, ZigBee based wireless communication module and personal computer (PC). The FPGA board performs as the heart of the proposed WQM system and it is programmed in very high speed integrated circuit hardware description language (VHDL) and C++ using Qsys tool and Nios-II SBT for Eclipse in Quartus II software. The proposed system collects the data of water quality such as water pH, water level, turbidity, carbon dioxide (CO₂) on the surface of water and water temperature in parallel and in real-time basis with high speed from five different sensor nodes. The performance of the proposed reconfigurable WSN system is verified through computer simulation and laboratory experiments.

I. Introduction

With increasing in the development of Wireless Sensor Network (WSN) technology, real-time environmental parameters are remotely monitored by means of real-time data acquisition, transmission, and processing. Postolache et al. [1] developed embedded software to monitor water quality using PIC Microcontroller, MPLAB and C compiler. In the proposed system, the software for data communication, data logging and graphical representation of the water quality data was developed in LabView software. Jinfeng and Shun [2] designed an aquaculture water quality monitoring system using MSP Microcontroller and ZigBee wireless module. The system collects, transmits, displays and queries the water quality parameters such as the temperature, dissolved oxygen concentration, pH value, and water level. Akila et al. [3] proposed the water quality monitoring system that detects the pH and temperature of the river water using sensors and Arduino board. Postolache et al. [4], [5] proposed a water quality monitoring system based on reconfigurable FPGA technology. The system consists of a set of water quality sensors to monitor conductivity, pH, and turbidity, a compact reconfigurable I/O (RIO) real-time embedded controller and an FPGA. In the system, the implementation of processing algorithms is difficult due to FPGA data representation format. Since the WSN platforms are used in IoT environmental monitoring applications for more cost effective and time, Vijayakumar and Ramya [6] designed a real-time water quality monitoring system in IoT environment. The system consists of multiple sensors to monitor water parameters and the raspberry as the main controller.