Research And Design Of Micro Wireless Multi-parameter Water Quality Sensor

With the continuous improvement of the social and economic level,the quality of the water environment is increasingly valued.Domestic water,drinking water,water discharged by enterprises,water for fishery and agricultural irrigation,etc.all need to be tested,and the use of water quality sensors for online real-time monitoring of the water environment has become an urgent need.The application of modern electronic measurement technology to the measurement of water quality parameter indicators has become one of the important development trends.This article designs and implements a wireless micro multi-parameter water quality monitoring system based on the actual needs of water quality parameter index detection.Its core is to develop a real-time,pollution-free,miniaturized,low-power multi-parameter water quality sensor module.The basic research ideas are: first,in-depth study of the measurement principles of water temperature,PH value,conductivity,and turbidity;second,the joint design of the sensor structure and software and hardware modules;finally,the integration of various modules Integration to form a miniaturized multi-parameter sensor module to achieve rapid real-time monitoring of water quality.The thesis combines weak signal detection technology,electrochemical detection technology,photoelectric detection technology and wireless ad hoc network communication technology,based on various water quality parameter detection principles,with STM32 processor as the core part,using digital lock-in amplification technology and conventional The method of combined parameter measurement processes the weak photoelectric signal.The digital quadrature phase-locked amplification method is used to extract the amplitude and phase of the signal to be measured,eliminating the effects of signal delay and environmental background noise,and effectively improving the detection accuracy,range and detection output signal-to-noise ratio of the system.Considering the different application scenarios of the water quality sensor and the modernized Internet of Things applications that increase its multi-function,this design has designed the Lora wireless communication function in the sensor,so that the multi-parameter sensor can realize low-power long-distance wireless while detecting water quality.Communication,each monitoring node can also realize self-organizing network,forming a wireless sensor network for online real-time monitoring.By optimizing the system,miniaturization and low cost of turbidity detection instruments have been achieved.The actual test experiment shows that the overall detection accuracy is ±3%FS and the measurement range meets the design requirements,which can meet the needs of conventional measurement.