Design Of WSN Node And Analysis Of Its Network For Monitoring Drinking Water Safety In Rural Areas

Water, the source of life, has straight impact to human's well-being. The quality of drinking water in rural areas such as turbidity, salinity, dissolved oxygen, nitrogen concentration, PH and conductivity, are influencing human's health at different levels. Moreover, the exceeding standard problems are directly threatening the drinking water safety in rural areas of our country. To ensure the safety of drinking water, and also to enhance the quality of life, we should keep track the water quality parameter in real time.The rising application of wireless sensor networks, WSN, integrates the data world closely with the physics world to realize the intelligent monitoring and control system. The thesis is to study the application of wireless sensor network for water quality monitoring, to research on the drinking water safety monitoring status in domestic and abroad, and to analyze the current WSN application status. A WSN node is designed for drinking water safety monitoring in rural area to address the problems of traditional monitoring system including delayed warning signal, data transmission difficulties and high cost. The node uses a STM32F103ZET6 as a processing core. The wireless communication module is made of WLK01L39 chip and its peripheral circuits. The sensor module is composed of the composite electrode sensor and its peripheral circuits from American ASI Company. The power module, serial module, GPS module, and power control module are also applied to the design. For the software, a sleep awakening mechanism is used to reduce the power consumption. The communication protocol, time synchronization algorithm and application program are also designed for the node. More protocols are created including the system initialization, data collecting and processing, routing protocol, and data transmission methodology, time synchronization algorithm and network access protocol. The node's main function are tested including its power consumption, communication distance, battery discharge, life cycle, function comparison and function extension. According to the test result, the node and its network system works stably and reliably. The communication distance of the network system is long with low power consumption, and its warning system is effective.The application of wireless sensor network in drinking water safety monitoring in rural areas is meeting the needs of intelligent monitoring drinking water quality. It is beneficiary to enhance drinking water quality in rural areas, to ensure the drinking water safety and to decrease the workload of the quality checkers.