Electronic tag for passive soil temperature and humidity measurement and use method thereof

Abstract

The invention relates to the technical field of soil detection, in particular to an electronic tag for passive soil temperature and humidity measurement and a use method of the electronic tag. The electronic tag comprises a tag shell, a soil temperature and humidity sensor is arranged in the tag shell, a probe interface is arranged in the tag shell, and a probe body is fixedly installed on the surface of the probe interface. The NFC chip with the model of ST25DV is adopted, 13.56 MHz radio-frequency signals emitted by a mobile phone or a reader-writer are efficiently rectified into 3.3 V direct current, short-time power supply buffering is achieved in combination with a 2.7 V / 10F energy storage capacitor, energy is supplied to an ultra-low power consumption master control MCU 22 and a high-precision soil temperature and humidity sensor, when radio-frequency energy is insufficient, the master control MCU records the current state to an EEPROM of the NFC chip, data are continuously transmitted during next power supply, and the power consumption is reduced. A traditional battery is completely replaced, a large amount of cost generated by battery replacement is avoided, and the technical standard of sustainability and high robustness of the agricultural sensor is redefined.

Description

Technical Field

[0001] The present invention relates to the technical field of soil detection, and particularly to a passive electronic tag for measuring soil temperature and humidity and its usage method. Background Art

[0002] With the intensification of the contradiction between global population growth and the shortage of arable land resources, precision agriculture and intelligent environmental monitoring technologies have become important breakthroughs for achieving sustainable agricultural development. Data from the Food and Agriculture Organization of the United Nations shows that optimizing irrigation management can increase crop yields by 20%-30% while reducing water resource waste by more than 40%. Against this background, soil temperature and humidity, as the core environmental parameters for crop growth, their accurate measurement is directly related to irrigation decision-making, fertility regulation, disaster warning, and planting planning.

[0003] Wireless temperature and humidity sensors rely on 3.6V lithium thionyl chloride batteries. Under the condition of collecting data once an hour, the battery life is only 6-12 months. When deploying 200 nodes in a thousand-acre farmland, the annual maintenance cost exceeds 120,000 yuan (including labor, battery replacement, and calibration), accounting for 30%-40% of the total equipment cost. Facing the high cost of battery replacement for temperature and humidity sensors, an electronic tag for passive measurement of soil temperature and humidity and its usage method are designed, which solves the inherent defect of battery power supply and redefines the technical standards for sustainable and highly robust agricultural sensors. Summary of the Invention

[0004] The purpose of the present invention is to provide an electronic tag for passive measurement of soil temperature and humidity and its usage method to solve the problem of the high cost of replacing batteries in traditional wireless temperature and humidity sensors mentioned in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution, an electronic tag for passive measurement of soil temperature and humidity and its usage method: including a tag housing, a soil temperature and humidity sensor is arranged inside the tag housing, a probe interface is arranged inside the tag housing, a probe body is fixedly installed on the surface of the probe interface, an NFC chip is arranged inside the tag housing, an NFC antenna is arranged inside the tag housing, a main control MCU is arranged inside the tag housing, an energy storage capacitor is arranged inside the tag housing, the soil temperature and humidity sensor is connected by a line with the probe interface, the NFC chip is wirelessly connected with the NFC antenna, and the energy storage capacitor, the NFC chip, and the main control MCU are symmetrically distributed on the tag housing.

[0006] Preferably, the probe body is made of anti-rust, alkali and salt corrosion resistant, and antioxidant material, and is coated with an anti-electrolysis coating on the surface. The probe body is inserted into the soil to transmit soil electrical parameters.

[0007] Preferably, the soil temperature and humidity sensor includes a soil moisture sensor and a soil temperature sensor.

[0008] Preferably, the NFC chip is electrically connected to the main control MCU, and the model of the NFC chip is ST25DV.

[0009] Preferably, the NFC chip powers the main control MCU and the soil temperature and humidity sensor through the radio frequency energy captured by the NFC antenna, and the data collected by the soil temperature and humidity sensor is transmitted to an external reading and writing device through the NFC chip.

[0010] A method of using a passive soil temperature and humidity measurement includes the following steps: S1: Vertically insert the probe body on the electronic tag into the soil to be measured, ensuring that the probe body is in full contact with the soil; S2: Turn on the NFC function and the supporting application program of the external reading and writing device; S3: Bring the reading and writing device close to the NFC antenna area of the electronic tag to power the electronic tag through a radio frequency signal; S4: After the main control MCU is started, it controls the soil temperature and humidity sensor to collect soil temperature and humidity data and stores the data in the NFC chip; S5: The reading and writing device reads the data in the NFC chip through the NFC protocol and displays the soil humidity percentage and temperature value in the application program.

[0011] Preferably, the NFC chip has an encrypted memory, and the data can only be read after passing the authorization key verification, and it supports the data write locking function.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. Through the NFC radio frequency energy capture technology, using the NFC chip of model ST25DV, the 13.56 MHz radio frequency signal emitted by the mobile phone or the reader / writer is efficiently rectified into 3.3V direct current, combined with a 2.7V / 10F energy storage capacitor to achieve short-term power supply buffering, to supply energy to the ultra-low power main control MCU22 and the high-precision soil temperature and humidity sensor. And when the radio frequency energy is insufficient, the main control MCU records the current state in the EEPROM of the NFC chip and continues to transmit data when powered again next time, completely replacing the traditional battery, avoiding the large costs generated by battery replacement, and redefining the technical standards of agricultural sensor sustainability and high robustness.

[0013] 2. The probe body is made of 316L stainless steel with a TFE anti-electrolysis coating, combined with an IP67 sealed housing, and can work continuously for ten years in extreme environments of -40°C to 85°C, solving the problem of frequent replacement of the probe body 13 due to corrosion and temperature. Description of the Drawings

[0014] Figure 1 Internal intuitive schematic diagram of the electronic tag of the present invention; Figure 2 Schematic diagram of the overall process layout of the present invention Figure 3 Schematic diagram of the actual cost comparison of the present invention.

[0015] In the figure: 1. Tag housing; 11. Soil temperature and humidity sensor; 12. Probe interface; 13. Probe body; 2. NFC chip; 21. NFC antenna; 22. Main control MCU; 23. Energy storage capacitor. Specific implementation manner

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] Please refer to Figures 1-3 , an embodiment provided by the present invention: An electronic tag for passive soil temperature and humidity measurement and its use method: including a tag housing 1. The housing 1 is made of engineering plastic with an IP67 protection level. A soil temperature and humidity sensor 11 is arranged inside the tag housing 1. A probe interface 12 is arranged inside the tag housing 1. A probe body 13 is fixedly installed on the surface of the probe interface 12. An NFC chip 2 is arranged inside the tag housing 1. An NFC antenna 21 is arranged inside the tag housing 1. The NFC antenna 21 adopts a circular coil antenna. A main control MCU 22 is arranged inside the tag housing 1. An energy storage capacitor 23 is arranged inside the tag housing 1. The soil temperature and humidity sensor 11 and the probe interface 12 are connected by a wire. The NFC chip 2 and the NFC antenna 21 are wirelessly connected. The energy storage capacitor 23, the NFC chip 2, and the main control MCU 22 are symmetrically distributed on the tag housing 1.

[0018] Furthermore, the probe body 13 is made of anti-rust, alkali and corrosion-resistant, and antioxidant material. The probe body 13 is 316L stainless steel with an anti-electrolysis coating on the surface. The probe body 13 is inserted into the soil to transmit soil electrical parameters. The overall length of the probe body 13 is 70 mm, of which 60 mm is the length inserted into the soil, and the upper 10 mm is locked by the screw on the probe interface 12.

[0019] Furthermore, the soil temperature and humidity sensor 11 includes a soil moisture sensor and a soil temperature sensor. The soil temperature and humidity sensor 11 is electrically connected through the probe interface 12 and the probe body 13, thus facilitating the detection of the temperature and humidity of the soil by the soil temperature and humidity sensor 11 through the probe body 13.

[0020] Furthermore, the NFC chip 2 is electrically connected to the main control MCU 22. The model of the NFC chip 2 is ST25DV, which has a built-in 4KB EEPROM memory and an AES-128 encryption engine, and communicates with the main control MCU 22 through the SPI interface. The main control MCU 22 has a built-in non-linear calibration table to automatically compensate for the dielectric constant deviation for different soil types. When the radio frequency energy is insufficient, the main control MCU 22 records the current state into the EEPROM of the NFC chip 2 and continues to transmit data when powered on next time.

[0021] Furthermore, the NFC chip 2 powers the main control MCU 22 and the soil temperature and humidity sensor 11 through the radio frequency energy captured by the NFC antenna 21. The data collected by the soil temperature and humidity sensor 11 is transmitted to the external reading and writing device through the NFC chip 2. The main control MCU 22 selects the ultra-low power consumption single-chip microcomputer STM32L051, with a working voltage of 1.8 - 3.6V and a sleep current of 0.3μA, and has a built-in 12-bit ADC and a temperature compensation circuit. Among them, the NFC antenna 21 and the sensor signal line are arranged in layers, and a 0.1mm thick copper shielding layer is added in the middle.

[0022] A usage method for passive soil temperature and humidity measurement includes the following steps: S1: Vertically insert the probe body 13 on the electronic tag into the soil to be measured, ensuring that the probe body 13 is in full contact with the soil; S2: Turn on the NFC function and the supporting application program of the external reading and writing device; S3: Bring the reading and writing device close to the NFC antenna 21 area of the electronic tag to power the electronic tag through the radio frequency signal; S4: After the main control MCU 22 is started, it controls the soil temperature and humidity sensor 11 to collect the soil temperature and humidity data and stores the data into the NFC chip 2; S5: The reading and writing device reads the data in the NFC chip 2 through the NFC protocol and displays the soil humidity percentage and temperature value in the application program.

[0023] Furthermore, the NFC chip 2 has a built-in encrypted memory, and the data can only be read after passing the authorization key verification, and it supports the data write locking function.

[0024] Furthermore, Working principle: Through the NFC radio frequency energy capture technology, using the NFC chip 2 of model ST25DV, the 13.56 MHz radio frequency signal emitted by the mobile phone or the reader / writer is efficiently rectified into 3.3V DC power, combined with the 2.7V / 10F energy storage capacitor 23 to achieve short-term power supply buffering, supply power to the ultra-low power consumption main control MCU 22 and the high-precision soil temperature and humidity sensor 11, and when the radio frequency energy is insufficient, the main control MCU 22 records the current state to the EEPROM of the NFC chip 2 and continues to transmit data during the next power supply, completely replacing the traditional battery, avoiding the large costs generated by battery replacement, and redefining the technical standards for the sustainability and high robustness of agricultural sensors.

[0025] The probe body 13 is made of 316L stainless steel with a TFE anti-electrolysis coating, combined with an IP67 sealed housing, and can work continuously for ten years in the extreme environment of -40°C to 85°C, solving the problem of frequent replacement of the probe body 13 caused by corrosion and temperature.

[0026] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. An electronic tag for passive soil temperature and humidity measurement, characterized in that: The invention comprises a tag housing (1), wherein a soil temperature and humidity sensor (11) is arranged inside the tag housing (1), a probe interface (12) is arranged inside the tag housing (1), a probe body (13) is fixedly mounted on the surface of the probe interface (12), an NFC chip (2) is arranged inside the tag housing (1), an NFC antenna (21) is arranged inside the tag housing (1), a main control MCU (22) is arranged inside the tag housing (1), and an energy storage capacitor (23) is arranged inside the tag housing (1); the soil temperature and humidity sensor (11) and the probe interface (12) are connected by line, the NFC chip (2) and the NFC antenna (21) are connected by wireless, and the energy storage capacitor (23), the NFC chip (2) and the main control MCU (22) are symmetrically distributed on the tag housing (1).

2. The electronic tag for passive soil temperature and humidity measurement according to claim 1, characterized in that: The probe body (13) is made of rust-proof, salt-alkali corrosion-resistant and oxidation-resistant material, and its surface is covered with an anti-electrolysis coating. The probe body (13) is inserted into the soil to transmit soil electrical parameters.

3. The electronic tag for passive soil temperature and humidity measurement according to claim 1 is characterized in that: The soil temperature and humidity sensor (11) comprises a soil moisture sensor and a soil temperature sensor.

4. The electronic tag for passive soil temperature and humidity measurement according to claim 1, characterized in that: The NFC chip (2) is electrically connected to the main control MCU (22), and the model of the NFC chip (2) is ST25DV.

5. The electronic tag for passive soil temperature and humidity measurement according to claim 4 is characterized in that: The NFC chip (2) supplies power to the main control MCU (22) and the soil temperature and humidity sensor (11) through radio frequency energy captured by the NFC antenna (21), and the data collected by the soil temperature and humidity sensor (11) is transmitted to an external reading and writing device through the NFC chip (2).

6. A method for using passive soil temperature and humidity measurement, characterized in that: The following steps are involved: S1: vertically insert the probe body (13) on the electronic tag into the soil to be tested, ensuring that the probe body (13) is in full contact with the soil; S2: Enable the NFC function of the external reader / writer and the supporting application; S3: placing the reading and writing device close to the NFC antenna (21) area of ​​the electronic tag, and supplying power to the electronic tag through a radio frequency signal; S4: After the main control MCU (22) is started, it controls the soil temperature and humidity sensor (11) to collect soil temperature and humidity data, and stores the data in the NFC chip (2); S5: The reader / writer device reads the data in the NFC chip (2) through the NFC protocol and displays the soil moisture percentage and temperature value in the application.

7. The method for using the passive soil temperature and humidity measurement according to claim 6, characterized in that: The NFC chip (2) has a built-in encrypted memory, data can only be read after verification by an authorization key, and supports a data write lock function.

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