CN202404090U

CN202404090U - Distributed detection device for soil humidity

Info

Publication number: CN202404090U
Application number: CN2011205760718U
Authority: CN
Inventors: 卢超
Original assignee: Shaanxi University of Technology
Current assignee: Shaanxi University of Technology
Priority date: 2011-12-30
Filing date: 2011-12-30
Publication date: 2012-08-29
Anticipated expiration: 2021-12-30

Abstract

The utility model relates to a device for measuring soil humidity, which Is characterized by being composed of a plurality of slave machines and a master machine. The slave machines take charge of acquisition for the soil humidity data of measuring points, the devices are installed in a plurality of measuring points of a to-be-detected soil in a distributed mode, and the master machine takes charge of collection and display for the soil humidity data. The master machine and the slave machines are in wireless two-way communication. The master machine and the slave machines are designed to comprise a soil humidity information part, a wireless module part, a key control part and a display module part. The soil humidity information part mainly comprises a soil humidity sensor and an A/D (analogue/digital) converter, and used for measuring soil humidity data via the sensor, and then conveying the soil humidity data to a microprocessor after passing through an A/D conversion; and the wireless module part is mainly composed of a wireless receiving-emitting chip, and used for receiving and emitting information. The distributed detection device for soil humidity disclosed by the utility model can monitor the humidity of a soil simultaneously, is simple in structure and convenient in use, and has the advantages of being small in size, good in visibility and the like; and simultaneously, a wireless mode is adopted, feeder connection is not needed, and the master machine and the slave machines can move at any time, so that extendibility is good.

Description

Distributed soil moisture pick-up unit

Technical field:

The utility model relates to a kind of device of measured soil humidity, is a kind of distributed soil moisture pick-up unit specifically.

Background technology:

Soil moisture is the water regime in the soil, and soil moisture is crossed crop suction difficulty when hanging down, even wilting; And humidity is too high, and the stain evil can take place again, so very important to the monitoring and the regulation and control of soil moisture.Simultaneously it is the regulating and controlling soil water regime basis of carrying out water-saving irrigation, realizing science water and irrigation automation scientifically, is most important information in the drought resisting mitigation work.How to measure agricultural land soil moisture quickly and accurately, for verifying crop growth soil moisture profit and loss in the phase, so that it is significant to make irrigation, fertilising decision-making or drainage measure etc.

Time domain reflectometry (TDR) is present a kind of a kind of common method that obtains soil moisture through the measured soil specific inductive capacity.The principle of TDR is the transmission speed V=c/ ε of electromagnetic wave along the transfer wire in the non-magnetic media; And be the transmission line of L for known length; V=L/t is arranged again, so can get ε=(ct/L) 2, wherein c is a light velocity of propagation in a vacuum; ε is the specific inductive capacity of non-magnetic media, and t is the transmission time of electromagnetic wave in lead.Electromagnetic wave is when being transferred to the lead terminal point; Some electromagnetic wave reflects along lead again; Like this incident with reflected to form a mistiming T; Therefore just can obtain the specific inductive capacity of soil through the incidence reflection mistiming T that measures the lead of electromagnetic wave in placing into the soil, and then obtain the humidity of soil.Traditional soil humidity measuring is single measurement point mostly, a sheet of soil region need manual work be with measurement mechanism one by one measurement point measure and statistics, waste time and energy.Even be the multimetering system, the wired measuring system of also most employings needs to implement the network layout engineering, and cable laying has increased system cost greatly, has reduced dirigibility, maintainability and the extensibility of system.

Be applied to wireless communication technology in the soil humidity measuring; Gather the information of each measurement point soil moisture in real time by soil humidity sensor; Through wireless data acquisition system humidity information is transferred to monitor terminal after treatment; The operator can select test point at handheld terminal, the soil moisture data that receive is shown on the display screen of handheld terminal through handling, thereby realize integrated, low-cost and easy-operating purpose.

Summary of the invention:

The technical matters that the utility model will solve is: a kind of wireless distributed soil moisture pick-up unit is provided, and it can monitor the humidity of a plurality of SOIL DISTRIBUTION measurement points automatically through wireless mode.

In order to solve the problems of the technologies described above, the utility model adopts following technical scheme: distributed soil moisture pick-up unit, this device is made up of a plurality of slaves and a main frame.Slave is responsible for the collection of measurement point soil moisture data, and device distributes and is installed in a plurality of measurement points of a slice soil to be measured, and main frame is responsible for the collection and the demonstration of soil moisture data.Be wireless two-way communication between main frame and the slave.

The design of described main frame and slave comprises the soil humidity information collection, and wireless module is by key control and display module four parts.The soil humidity information collection mainly is made up of soil humidity sensor and A/D converter, through giving microprocessor through after the A/D conversion after the sensor measurement soil moisture data; Wireless module mainly is made up of radio transmitting and receiving chip, is used for receiving and emission information.Slave collects soil humidity information in the single-chip microcomputer through sensor, then in single-chip microcomputer according to certain agreement and error-detection mechanism configuration frame, launch through wireless module.Main frame receives every frame information with interrupt mode, then the frame information that receives is carried out error-detecting, has judged whether error code information.If there is not error code, extract data bit, calculate humidity value, the humidity information of sending a plurality of slaves shows on display module.

The beneficial effect of the utility model is:

The utility model can be monitored the humidity of a slice soil simultaneously, and it is simple in structure, easy to use, has miniaturization, characteristics such as visual good, adopts wireless mode simultaneously, need not feeder line to connect, and main frame and slave can move at any time, and extensibility is good.

Description of drawings:

Fig. 1 is the structured flowchart of the said distributed soil moisture pick-up unit of the utility model.

Fig. 2 is the structured flowchart of slave in the said pick-up unit of the utility model.

Fig. 3 is the CC of said wireless module of the utility model and microprocessor.

Fig. 4 is the CC of the said microprocessor of the utility model, A/D conversion and soil humidity sensor.

Fig. 5 is the CC of said microprocessor of the utility model and display module.

Embodiment:

Below in conjunction with accompanying drawing and embodiment the utility model is further specified.Present embodiment only is the description to the utility model embodiment, and the scope to the utility model does not have any restriction.

The structured flowchart of the described distributed soil moisture pick-up unit of the utility model is as shown in Figure 1: in the main frame; Single-chip microcomputer adopts AT89S52; Display module adopts LCD1602, and the button control module adopts 4 free-standing buttons, the PTR2000 that wireless module adopts the NRF401 chip to constitute.

The structured flowchart of slave is as shown in Figure 2 in the described distributed soil moisture pick-up unit of the utility model: soil humidity sensor adopts the XR61-TDR2 type soil humidity sensor based on time domain reflectometry; Microprocessor adopts AT89S52; 8 successive approximation analog to digital converter ADC0809 are adopted in the A/D conversion, the PTR2000 that wireless module adopts the NRF401 chip to constitute.Main frame is monitored through with the radio communication of slave the humidity data of each measurement point of soil being collected effectively.

Described wireless module is selected the PTR2000 module of microminiature, super low-power consumption for use.PTR2000 is based on the NRF401 chip development, and wireless data transmission chip NRF401 is operated in the international ISM band of 433MHz, the FSK modulation and demodulation, and antijamming capability is strong; Adopt the PLL frequency synthesis technique, frequency stability is good; Sensitivity is up to-105dBm, and maximum transmission power reaches+10dBm; Data rate can reach 20Kbit/s.The NRF401 chip can directly link to each other with serial ports, and the single-chip microcomputer delivery outlet can directly control wireless receiving and dispatching, and CC is as shown in Figure 3.Totally 10 pin: VCC of PTR2000 are system power supply; GND is power supply ground; DIN is the module data input; DOUT is module data output; TXEN is that reiving/transmitting state is selected, and TXEN=1 is an emission state, and TXEN=0 is an accepting state; PWR_UP is duty control, can be set to the little power consumption state of normal operating conditions and standby; CS is channel selection, and CS=0 is operated in 433.93MHz, and CS=1 is operated in 433.33MHz.AT89S52 goes out data transmission through the PTR2000 wireless module in slave, has used three common I/O mouths and serial ports, and host machine part AT89S52 joins consistent with slave with PTR2000.

Described soil humidity sensor adopts XR61-TDR2 type soil humidity sensor, is output as direct current 0～2.5V, and 8 successive approximation analog to digital converter ADC0809 are adopted in the A/D conversion, and CC is as shown in Figure 4.Humidity signal converts digital signal to through the AD translation interface and sends into single-chip microcomputer; The course of work of ADC0809 chip is: at first importing 3 bit address ADDC, ADDB and ADDA is 000; Select the IN0 passage, and make ALE=1, the address is deposited in the address latch.At the START rising edge successive approximation register is resetted, negative edge starts the AD conversion, and the signal of EOC output afterwards step-down indication conversion is carried out, and EOC becomes high level indication AD EOC, and result data deposits latch in.Through interrupting application, when the OE input high level, open ternary output latch, the digital quantity of transformation result outputs on the data bus.

Described display module adopts LCM-1602 character mode lcd module; Have characteristics such as volume is little, low in energy consumption, displaying contents is abundant; The character generation memory stores that 1602 Liquid Crystal Modules are inner 160 different dot character figures; The operation of its read-write operation, screen and cursor all is to realize through instruction programming, and the inner controller of Liquid Crystal Module has 11 steering orders.Be connected simply with single-chip microcomputer, 8 I/O mouths link to each other with 8 bit data ends of Liquid Crystal Module, join with RS, R/W, the E of Liquid Crystal Module respectively with three control mouths again.The P0 mouth of single-chip microcomputer connects 8 bit data in the device, and with P2.7, P2.6, P2.5, meet RS, R/W, E respectively, we have also directly added the exclusion of 1k Ω at P0 mouth and Liquid Crystal Module owing to there is not pull-up resistor in the P0, and concrete CC is as shown in Figure 5.Single-chip microcomputer is followed strict sequential with Liquid Crystal Module and is programmed when communicating by letter.

Above-described embodiment, related data and computing method are only as schematic illustration, the equivalent arrangements of being done according to the utility model claim such as, the technology that all should be the utility model contains.

Claims

1. distributed soil moisture pick-up unit, it is characterized in that: this device is made up of a plurality of slaves and a main frame, and slave is responsible for the collection of measurement point soil moisture data; Device distributes and is installed in a plurality of measurement points of a slice soil to be measured; Main frame is responsible for the collection and the demonstration of soil moisture data, is wireless two-way communication between main frame and the slave, and the design of main frame and slave comprises the soil humidity information collection; Wireless module emission, reception are by key control and display module four parts.

2. distributed soil moisture pick-up unit according to claim 1 is characterized in that: described soil humidity information collection is soil humidity sensor and A/D converter.

3. distributed soil moisture pick-up unit according to claim 1, it is characterized in that: described wireless module is made up of radio transmitting and receiving chip, is used for receiving and emission information.

4. distributed soil moisture pick-up unit according to claim 1 is characterized in that: described display module is a LCD display.