Development Of Automatic Collection System For Cave Drip-water Based On Cortex-M3

The most extensive karst landform in the world is distributed in southwest China.Influenced by the geological structure with less soil and more rocks,even though the region is rich in rainfall,the available water resources are very scarce,making local people still live in the state of severe water shortage.Therefore,to study the distribution and flow of groundwater in karst areas,as an helper to find new fresh water resources and solve the problem of water shortage in People's Daily life is extremely important.We set up two observation points on the ground and underground in total,and developed surface rainfall data acquisition system and karst underground water drop monitoring system.The researchers hope to find out the distribution law of underground runoff by comparing and analyzing the data monitored by the two systems and the results of chemical analysis of collected water samples,so as to provide scientific basis for establishing the conduction model of groundwater.First,the main contents of this paper is water droplet monitoring and automatic sampling control system,which includes monitornng and recording the change of water drop velocity in underground cavern in detail for a long time and collecting the monitored droplets and the water samples automatically.There are two modes of sample collection:!.Automatic sampling according to the sampling frequency set by the researcher;2.Immediately sampling and halving the sampling frequency set by the researcher when drops speed up,which shows new sources of water appear.Secondly,the monitored and recorded data should be stored in a timely manner,and it should be convenient for researchers to set control parameters and obtain data.Finally,the low-power system power supply can ensure the system to work in the field for a long time in an unmanned environment.In order to realize the function of the system,we choose STM32 as the main controller,use the independently developed water drop pressure sensor to sense the water drop signal,and combine the independently designed water drop signal conditioning circuit to let the water drop signal be recognized by the controller,so as to realize the monitoring of water drop velocity.SPI interface is used to read and write data on Flash memory chip to achieve data storage function.The host computer realizes parameter setting and data acquisition through wireless data transmission technology.For low power system power supply,nonlinear switching power supply technology is adopted to realize the minimum power consumption.On the basis of the predecessors,we design a better automatic sampling mechanical device.With the assistance of the electronic control system,we realized the automatic sampling function of the machine.Last,through the simulation test,all the setting functions of the system have been realized accurately.