Design Of Automatic Sand Sampler Monitoring System For Soil Wind Erosion Measurement

As an important instrument for studying wind erosion in soil,the sand trap is mostly required to be manually involved in collecting and calculating;Sand trap automation level is not high.Therefore,the research group relied on the mechanical structure of soil sand erosion detection sand collection instrument to design and develop a fully automatic sand trap detection system.The whole sand trap monitoring system is composed of multiple sensor nodes.The system consists of a main controller node and multiple auxiliary sensor nodes.The system uses ZigBee wireless networks to transmit sensor data.The ZigBee coordinator integrated in the main sensor is used to set up a network and control other auxiliary sensor nodes to start collecting tasks.The data is finally collected in the main sensor,and is stored and sent in a packed code.Two high-linearity load cells with rated load of 600g are used as mass conversion devices for sensor nodes.Analog-to-digital converters in the system use Analog Devices’ high-resolution(24-bit),high-accuracy(±30ppm)low-noise(8nV)AD7192 to provide data accuracy for the sand trap monitoring system.The monitoring system also integrates a variety of environmental sensors,Easy access to different types of data to provide data support for further in-depth study of soil erosion.With stepper motor driver chip A4988,it is possible to achieve sand-mass overflow and automatically dump dust.The main sensor node system has a built-in FatFs file system.It automatically changes the file storage location according to the date and time.It can realize that each sand collection node data is stored in the local SD card by MAC address.The system can count and upload the online quantity of the sand trap node and the corresponding MAC address of the sand trap.In the monitoring system test experiment,the offset voltage of the analog-to-digital converter hardware noise measured zero differential input is 221.9nV and 321.6nV,respectively;when the system is connected to the load cell,the data is stable and there is no obvious abnormal fluctuation,and the measured data variances are continuously It is 0.36,0.24;in the mass calibration experiment of the load cell,the fitting function of the output value of the quality and analog-to-digital converter is obtained,and the linearity is ideal.