关键词: 水肥一体化, 远程监测, 肥液参数, 双重ADC同步采样, 数据滤波

Abstract: Integrate water-fertilizer technology is a crucial method for conserving water, reducing fertilizer use, and minimizing ecological pollution. Among its core challenges, the precise detection of fertilizer liquid EC and pH value, along with the stable remote transmission of these parameters, are key areas of research in the development of water-fertilizer integration equipment. This study focused on the applied research of accurately monitoring fertilizer solution parameters in water-fertilizer integration systems. It carefully considered the detection range and resolution of voltage signals, and designed a high-precision voltage detection circuit to convert, divide, follow, and filter the raw signals output by the fertilizer sensors. After the high-precision voltage detection circuit, the processed EC and pH sensor signals were then input into the controllers high-speed ADC module for dual synchronous rule sampling. This enabled the real-time conversion of analog signals to digital signal, and synchronized acquisition of EC and pH values. To balance signal filtering with real-time responsiveness, an appropriate filter length was selected to implement a sliding average filter on the digital signal, effectively eliminating cyclic and high-frequency random noise and ensuring the accuracy of ADC sampling results. The integration of high-precision hardware voltage detection and an efficient sensor data processing algorithm enabled accurate detection of fertilizer solution EC and pH values. The processed data, standardized in JSON format by the controller, were transmitted via RS232 communication to a 4G DTU module, and then remotely uploaded to a cloud platform using the MQTT protocol. This provided valuable input for user decision-making reference or crop water-fertilizer modeling. Experimental validation demonstrated that the system achieved high-accuracy voltage detection, supported by a flexible and efficient data processing algorithm. The average relative error of voltage measurement was only 1.98‰, while remote communication was stable and reliable, with a data transmission and reception success rate of 99.88%.

Key words: water and fertilizer integration, remote monitoring, fertilizer parameters, dual ADC synchronous sampling, data filter