LoRaWAN tilt angle sensor system with high precision and low power consumption

Abstract

The invention relates to a high-precision low-power-consumption LoRaWAN tilt angle sensor system. The system comprises a lithium thionyl chloride battery management circuit used for realizing charging and discharging management of a lithium thionyl chloride battery; the power switch circuit is connected with the lithium thionyl chloride battery management circuit and is used for providing voltage output; the temperature sensor circuit is used for detecting the system environment temperature and sending the system environment temperature to the single chip microcomputer; the three-axis accelerometer and power supply and discharge control circuit is used for detecting three-axis acceleration data of the current position and sending the three-axis acceleration data to the single chip microcomputer; the LoRaWAN wireless communication module circuit is connected with the single-chip microcomputer and is used for realizing wireless communication of the system; and the single-chip microcomputer is used for realizing power supply control and angle calculation of each circuit. Compared with the prior art, the sensor has the advantages of large effective measuring range, high precision, small sensitivity temperature drift, long service life of the battery and the like, and is not influenced by small differences of gravitational acceleration values at different altitudes and regions.

Description

Technical Field

[0001] The present invention relates to the field of inclination sensors, and in particular to a high-precision and low-power consumption LoRaWAN inclination sensor system. Background Art

[0002] The inclination sensor is a device used to measure the inclination angle of an object relative to the horizontal plane. It determines the inclination angle by detecting the component of gravity acceleration on the sensor axis. It is widely used in the fields of construction, automobiles, aerospace, industrial equipment, etc. to monitor and control the inclination state.

[0003] At present, the inclination sensor uses MEMS accelerometer to detect the static inclination angle, usually by performing an inverse sine function operation on the gravity acceleration component on a certain axis of the accelerometer to obtain the inclination angle value. Since the output change caused by the input change of the sine function is very small when it is close to ±90°, that is, the sensitivity is low, this method cannot perform high-precision large-angle range measurement. In addition, the detection of static inclination angle by MEMS accelerometer is also easily affected by the actual gravity acceleration values ​​in different regions or latitudes, and there are also problems such as high power consumption and short battery life. Summary of the invention

[0004] In order to solve the technical problems in the background technology, the present invention provides a high-precision and low-power consumption LoRaWAN tilt sensor system, which includes:

[0005] Lithium-ion battery management circuit: used to realize the charge and discharge management of lithium-ion batteries;

[0006] Power switch circuit: connected to the lithium-ion battery management circuit to provide voltage output;

[0007] Temperature sensor circuit: used to detect the system ambient temperature and send it to the microcontroller;

[0008] Three-axis accelerometer and power supply and discharge control circuit: used to detect the three-axis acceleration data of the current position and send it to the single-chip microcomputer;

[0009] LoRaWAN wireless communication module circuit: connected to the microcontroller to achieve wireless communication of the system;

[0010] Single chip microcomputer: It is respectively connected to the power switch circuit, temperature sensor circuit, three-axis accelerometer and power supply and discharge control circuit and LoRaWAN wireless communication module circuit to realize power supply control and angle calculation of each circuit.

[0011] Furthermore, the lithium-ion battery management circuit includes a lithium-ion battery, a charge and discharge management module, and an external power output port. The charge and discharge management module is composed of a charge and discharge management chip, a resistor, and a jumper resistor. The negative electrode of the lithium-ion battery is grounded, and the positive electrode is connected to the power supply pin of the charge and discharge management chip and the external power output port through a Schottky diode. The external power output port is connected to the power switch circuit.

[0012] Furthermore, the power switch circuit includes a battery power supply interface connected to the external power output port of the lithium-ion battery management circuit, a power input port, a jumper interface, a low-voltage drop anti-reverse connection sub-circuit and an external power switch. The power input port is connected to the external power switch, the jumper interface and the low-voltage drop anti-reverse connection sub-circuit through a self-recovery fuse and an anti-reverse connection dual diode in sequence, and the jumper interface is connected in parallel with a jumper resistor.

[0013] Furthermore, the low voltage drop anti-reverse connection sub-circuit includes a PMOS tube and a resistor, the gate of the PMOS tube is grounded through the resistor, the drain is connected to the jumper interface, and the source serves as the power output terminal VDD of the power switch circuit.

[0014] Furthermore, the temperature sensor circuit includes a temperature sensor chip, and the temperature sensor chip communicates with the single-chip microcomputer using a single-bus communication interface, and is powered by a GPIO interface of the single-chip microcomputer.

[0015] Furthermore, the three-axis accelerometer and power supply and discharge control circuit include a three-axis MEMS accelerometer chip and a power supply and discharge control sub-circuit, one end of the power supply and discharge control sub-circuit is connected to the accelerometer power supply control pin of the single-chip microcomputer, and the other end is connected to the power supply pin of the three-axis MEMS accelerometer chip. The three-axis MEMS accelerometer chip is connected and communicated with the single-chip microcomputer through an SPI interface, and the single-chip microcomputer calculates the angle data through an inverse tangent algorithm and outputs it.

[0016] Furthermore, the power supply and discharge control subcircuit is composed of a resistor, a TVS tube and a capacitor. The accelerometer power supply control pin of the single-chip microcomputer is connected to the power supply end of the three-axis MEMS accelerometer chip through the resistor. The TVS tube and the capacitor are connected in parallel, one end of which is connected between the resistor and the power supply end of the three-axis MEMS accelerometer chip, and the other end is grounded.

[0017] Furthermore, the LoRaWAN wireless communication module circuit includes a LoRaWAN module power supply control subcircuit and a LoRaWAN module subcircuit, the LoRaWAN module power supply control subcircuit includes a PMOS tube and a transistor, the base of the transistor is connected to the wireless communication module power supply control pin of the single-chip microcomputer, the emitter is grounded, the collector is connected to the gate of the PMOS tube, the drain of the PMOS tube is connected to the LoRaWAN module subcircuit, and the source is connected to the output end of the power switch circuit.

[0018] Furthermore, the LoRaWAN module subcircuit includes a LoRaWAN module and an indicator light module, a reset module and an antenna module respectively connected to the LoRaWAN module.

[0019] Furthermore, the single-chip microcomputer is connected to a crystal oscillator chip used by the single-chip microcomputer MCU core and a crystal oscillator chip used by a low-power RTC real-time clock module, and different crystal oscillator frequencies are set in working modes corresponding to different workloads to reduce power consumption.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. Low power consumption: The LoRaWAN tilt sensor system designed by the present invention adopts a low-power circuit architecture, which can ensure low power consumption in product operation and sleep. The sleep power consumption of the present invention is 30uA, and the power consumption when waking up to detect the angle is only 6mA. It only takes 0.28 seconds to complete an angle detection. It can ensure long-term operation of more than 5 years when powered by a battery, which is longer than the battery life of about 3 years of existing products.

[0022] 2. Large range: The present invention adopts a three-axis MEMS accelerometer chip, three-axis measurement and three-axis angle output. Due to the use of three-axis angle solution, it overcomes the performance degradation and reduced accuracy caused by the smooth curve change near the ±90° angle when performing single-axis inverse sine solution.

[0023] 2. High precision: The present invention adopts six-position calibration algorithm + three-axis angle solution + multiple curve angle interpolation algorithm to achieve high-precision and large-range output of three-axis ±90°. The accuracy can reach within ±0.01° in the range of ±85°, and can reach ±0.5° in the range of ±85° to ±90°. At the same time, since the three-axis algorithm adopts the three-axis acceleration ratio to solve the angle, it can effectively suppress the sensitivity temperature drift of the accelerometer and offset the influence of different acceleration values ​​at different latitudes. Therefore, it can also ensure that the design can be calibrated in a fixed place and used in various parts of the world. It can still guarantee high precision, while the existing inverse sine solution cannot guarantee accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1It is a circuit principle block diagram of the present invention;

[0025] Figure 2 This is the circuit schematic diagram of the lithium-ion battery management circuit;

[0026] Figure 3 is a circuit schematic diagram of a power switch circuit;

[0027] Figure 4 is the circuit schematic diagram of the temperature sensor circuit;

[0028] Figure 5a The schematic diagram of the circuit for the supply and discharge control subcircuit;

[0029] Figure 5b is the circuit schematic diagram of the three-axis accelerometer subcircuit;

[0030] Figure 6a It is the circuit schematic diagram of the single chip microcomputer and peripheral circuits;

[0031] Figure 6b This is the circuit schematic diagram of the external crystal oscillator circuit of the single-chip microcomputer;

[0032] Figure 7a Circuit diagram of the power supply control subcircuit for the LoRaWAN module;

[0033] Figure 7b This is the circuit schematic of the LoRaWAN module and indicator light subcircuit;

[0034] Figure 8a is the circuit schematic diagram of the key sub-circuit;

[0035] Figure 8b It is the circuit schematic diagram of the indicator light sub-circuit;

[0036] Fig. 9 It is a flow chart of the working principle of the present invention;

[0037] Fig.10 This is the flow chart of angle calculation and calibration. DETAILED DESCRIPTION

[0038] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0039] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0040] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0042] In the description of this embodiment, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0043] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0044] Example

[0045] like Figure 1 As shown, the present invention provides a high-precision, low-power consumption LoRaWAN tilt sensor system for realizing high-precision, large-range, low-power consumption three-axis angle detection. The system includes a single-chip microcomputer and a lithium-ion battery management circuit, a power switch circuit, a temperature sensor circuit, a three-axis accelerometer and a power supply and discharge control circuit, a LoRaWAN wireless communication module circuit, and a button and indicator light circuit respectively connected to the single-chip microcomputer.

[0046] like Figure 2 As shown, the lithium-ion battery management circuit includes a lithium-ion battery BT201, a composite pulse capacitor C201, a Schottky diode D201, a charge and discharge management chip U201, a resistor R201, a jumper resistor R202 and an external power output port P201.

[0047] The negative pole of the lithium-ion battery BT201 (model ER34615 in this example) is grounded, and the positive pole is connected to pin 1 of the Schottky diode D201, which is used to prevent the positive and negative poles of the lithium-ion battery BT201 from being installed incorrectly and the composite pulse capacitor C201 from reversely charging the non-rechargeable lithium-ion battery BT201. The composite pulse capacitor C201 is connected between pin 3 of the Schottky diode D201 and ground. The charge and discharge management chip U201, resistor R201 and jumper resistor R202 form a charge and discharge management circuit for the composite pulse capacitor C201 to prevent over-discharge of the composite pulse capacitor C201. Pin 2 of the charge and discharge management chip U201 is grounded and connected to pin 4 through jumper resistor R202. Pins 4 and 5 are both grounded, and pin 3 is connected to pin 3 of the Schottky diode D201 and the external power output port P201 through resistor R201.

[0048] The battery discharge management circuit, as the battery power supply part of the present invention, can achieve a battery life cycle of more than 10 years with an extremely low self-discharge rate through the combination of the lithium-ion battery BT201 and the composite pulse capacitor C201, in conjunction with the low-power charge and discharge management chip U201 (model DW02 in this example). At the same time, it can also carry large currents in a short period of time such as wireless communications.

[0049] like Figure 3 As shown, the power switch circuit includes a power input port P4 used for debugging, an anti-reverse connection dual diode D1, a self-recovery fuse F1, an external power switch J1, a battery power supply interface J2, a jumper interface P2, a jumper resistor R6, and a low-voltage drop anti-reverse connection sub-circuit. One end of the power input port P4 is connected to one end of the jumper interface P2, one end of the battery power supply interface J2, and the Vi pin of the external power switch J1 respectively through the self-recovery fuse F1 and the anti-reverse connection dual diode D1, and the other ends of the power input port P4 and the battery power supply interface J2 are grounded respectively. The other end of the jumper interface P2 is respectively connected to the Vo pin of the external power switch J1 and the low voltage drop anti-reverse connection sub-circuit. The function of the jumper interface P2 is to conduct the circuit for testing when the external power switch J1 is not welded. The L- pin of the external power switch J1 is grounded through the resistor R1, and the L+ pin is connected to the microcontroller chip U3. The low voltage drop anti-reverse connection sub-circuit is composed of a PMOS tube Q2 and a resistor R8. The gate of the PMOS tube Q2 is grounded through the resistor R8, the drain is connected to the jumper interface P2, and the source is used as the power output terminal VDD of the power switch circuit;

[0050] The anti-reverse connection dual diode D1 is used to prevent the positive and negative poles of the power supply from being reversed and burning out the back-end circuit components when the inclination sensor main board works independently without the power board; the self-resetting fuse F1 is used to prevent overcurrent; the jumper interface P2 is used for circuit conduction during debugging; the jumper resistor R6 is connected to both ends of the jumper interface P2 and is used as an option; the battery power supply interface J2 is connected to the external power supply output port P201 through a wire; the low-voltage drop anti-reverse connection sub-circuit is used to prevent the power from the battery power supply interface J2 from being reversed.

[0051] In the present invention, the use of the external power switch J1 can ensure zero power consumption of the inclination sensor product during the shipping and transportation process. Since the external power switch J1 is a physical switch with an indicator light, the switch is closed during transportation to cut off the current loop, so zero power consumption can be achieved. The low-voltage drop anti-reverse connection circuit has an extremely low voltage drop, which can effectively reduce unnecessary energy consumption.

[0052] like Figure 4 As shown, the temperature sensor circuit includes a high-precision temperature sensor chip U2 (model M1820P in this example), which communicates with the microcontroller using a single bus communication interface, and is powered by the microcontroller GPIO interface. The power is only supplied when in use, and is turned off when not in use to reduce power consumption.

[0053] The three-axis accelerometer and the power supply and discharge control circuit include a three-axis accelerometer chip U1 (in this example, the ADXL35x series chip is used) and a power supply and discharge control subcircuit directly controlled by a single-chip microcomputer, such as Figure 5a As shown, the power supply and discharge control subcircuit is composed of a resistor R2 and a TVS tube D2, a capacitor C3 and a resistor R15. The control pin ACC_POWER of the single-chip microcomputer chip U3 is connected to the power supply terminal AVDD of the three-axis accelerometer through the resistor R2. The TVS tube D2 and the capacitor C3 are connected in parallel, one end of which is connected between the resistor R2 and the power supply terminal AVDD of the three-axis accelerometer, and the other end is grounded. The power supply and discharge control subcircuit is only turned on when the three-axis accelerometer chip U1 is in use, and is turned off to save power when not in use.

[0054] like Figure 5b As shown, as the core component of the inclination sensor, the three-axis accelerometer chip U1 specifically adopts a three-axis MEMS accelerometer chip. The capacitors around the chip are its power supply bypass and decoupling capacitors. The three-axis accelerometer chip U1 is connected to the microcontroller through the SPI interface.

[0055] like Figure 6a and 6bAs shown, the single-chip microcomputer and peripheral circuits include a single-chip microcomputer chip U3 and peripheral circuits. In the peripheral circuits, Y1 and Y2 are external crystal oscillator chips, respectively. Y1 is used for the single-chip microcomputer MCU core, and Y2 is used for the low-power RTC real-time clock module inside the single-chip microcomputer, and is equipped with load capacitors. C20~C23 are power supply bypass and decoupling capacitors of the single-chip microcomputer chip U3, respectively. In this example, the single-chip microcomputer chip U3 adopts a low-power ARM core single-chip microcomputer chip, which has extremely low power consumption. The peripheral devices are the minimum system of the single-chip microcomputer, and J3 is the SWD program burning and debugging. Test interface, J4 is the debugging serial port for product calibration, the single-chip microcomputer chip U3 uses different crystal oscillator frequencies to minimize power consumption under different workloads, realizes data collection of chips such as the three-axis accelerometer chip U1 and the high-precision temperature sensor chip U2, and solves data such as angle and temperature. For example, when solving the angle at full speed, the operating frequency of the single-chip microcomputer is set to 16MHz; when waking up periodically to collect accelerometer data, the operating frequency of the single-chip microcomputer is set to 1MHz; before entering sleep mode, the operating frequency of the single-chip microcomputer is set to 32.768kHz.

[0056] The LoRaWAN wireless communication module circuit includes the LoRaWAN module power supply control subcircuit and the LoRaWAN module and indicator light subcircuit, such as Figure 7a As shown, the core components of the LoRaWAN module power supply control subcircuit include PMOS tube Q4 and transistor Q5. The base of transistor Q5 is connected to pin 21 PW_CTL_LR of the microcontroller chip U3, the emitter is grounded, the collector is connected to the gate of PMOS tube Q4, the drain of PMOS tube Q4 is connected to the LoRaWAN module U5, and the source is connected to the output terminal VDD of the power switch circuit. The remaining decoupling capacitors and TVS diodes form a power supply bypass to prevent excessive transient voltage that may occur when the circuit is turned on.

[0057] like Figure 7bAs shown, the LoRaWAN module and indicator light subcircuit include a LoRaWAN module U5 communicating with the single-chip microcomputer chip U3, and an indicator light module, a reset module and an antenna module respectively connected to the LoRaWAN module U5. The indicator light module is arranged between pins 1 and 3 of the LoRaWAN module U5 and the output end of the LoRaWAN module power supply control subcircuit to indicate power supply and sleep; the reset module includes a reset capacitor C33 and a reset resistor R29, and the output end VBAT of the LoRaWAN module power supply control subcircuit is connected to the reset pin of the LoRaWAN module U5 through the reset resistor R29, one end of the reset capacitor C33 is connected to the reset pin of the LoRaWAN module U5, and the other end is grounded; the antenna module includes an antenna connector J5 (the model number is 20279-001E-01 in this example) and matching capacitors and resistors. The LoRaWAN module U5 communicates with the single-chip microcomputer chip U3 through the UART port, and is powered only during communication, and is powered off when not communicating to achieve low power consumption.

[0058] The button and indicator light circuit includes a button subcircuit and an indicator light subcircuit, such as Figure 8a As shown, the key subcircuit is used to test the manual triggering of the wireless communication function, including a key S1, a resistor R23, a capacitor C26 and a resistor R21. The output end of the power switch circuit is connected to the 29th pin RES_KEY of the microcontroller chip U3 through the key S1 and the resistor R21 in turn. The resistor R23 and the capacitor C26 are connected in parallel, one end is grounded, and the other end is connected between the key S1 and the resistor R21; Figure 8b As shown, the indicator light sub-circuit includes light emitting diodes D5 and D6, which are used to indicate the working status of the product. One end of the light emitting diode D5 is grounded, and the other end is connected to pin 28 of the single-chip microcomputer chip U3 through a resistor R17. One end of the light emitting diode D6 is grounded, and the other end is connected to pin 18 of the single-chip microcomputer chip U3 through a resistor R18. The button sub-circuit and the indicator light sub-circuit will not generate power consumption in the sleep state, which can further achieve low power consumption.

[0059] like Fig. 9As shown, the present invention realizes a high-precision, large-range, low-power LoRaWAN tilt sensor system. The main process of running the program in the single-chip microcomputer chip includes initialization and main loop. During the initialization process, the power supply control and initialization of the counting single-chip peripherals, three-axis accelerometer, temperature sensor and other components are completed. After entering the main loop, the watchdog is fed first, and then the power supply voltage of the three-axis accelerometer, temperature sensor and single-chip microcomputer is collected, and the angle, temperature and voltage data are calculated. Then, the data is sent to the remote server platform through wireless communication through the LoRaWAN module. After sending the data, the tilt sensor will enter a low-power sleep state. The low-power RTC real-time clock module inside the single-chip microcomputer will wake up the system regularly and cycle the above steps periodically. The present invention adopts a periodic sleep-wake-up low-power design of the main process to reduce the active time of the inclinometer as much as possible; by controlling the power supply of components such as the temperature sensor, accelerometer chip, and LoRaWAN module, the power supply of these circuits is turned off when not needed, and at the same time, the operating frequency of the single-chip microcomputer is reduced to finally achieve low-power operation of the inclinometer product. Under the condition of reporting one piece of data every 5 minutes, an ER34615 lithium-ion battery can work continuously for about 8 years, which exceeds the 3-5 years of service life of similar products at home and abroad under the same working conditions.

[0060] like Fig.10 As shown, the angle solution and calibration process of the present invention is that the single chip microcomputer samples the three-axis accelerometer through the SPI interface, and then filters the collected original values ​​to remove high-frequency noise and jitter, and then uses the six-position calibration algorithm to perform installation alignment error, cross-axis and sensitivity preliminary calibration on the filtered acceleration value, and then uses the three-axis inverse tangent algorithm to solve the angle. This step is the basis for achieving a large range and high precision of the three axes. The angle is then calibrated and calibrated, and finally the factory zero point calibration is performed. At this point, the entire angle solution and calibration process is completed, and the high-precision and large-range output of the three axes of ±90° is achieved.

[0061] The accuracy of the inclination sensor system of the present invention can reach within ±0.01° within the range of ±85°, and can reach ±0.5° within the range of ±85° to ±90°. At the same time, since the three-axis ratio is used in the three-axis angle solution algorithm, the sensitivity will not be affected by different acceleration values ​​in different places, and it is also ensured that the inclination sensor product will not have the problem of accuracy loss caused by differences in gravitational acceleration when used at different latitudes or altitudes. Therefore, the present invention can achieve more comprehensive high-precision measurement. After actual test verification, the final accuracy level is better than the accuracy of similar products at home and abroad.

[0062] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A high-precision, low-power LoRaWAN tilt sensor system, characterized in that: The system includes: Lithium-ion battery management circuit: used to realize the charge and discharge management of lithium-ion batteries; Power switch circuit: connected to the lithium-ion battery management circuit to provide voltage output; Temperature sensor circuit: used to detect the system ambient temperature and send it to the microcontroller; Three-axis accelerometer and power supply and discharge control circuit: used to detect the three-axis acceleration data of the current position and send it to the single-chip microcomputer; LoRaWAN wireless communication module circuit: connected to the microcontroller to achieve wireless communication of the system; Single chip microcomputer: It is respectively connected to the power switch circuit, temperature sensor circuit, three-axis accelerometer and power supply and discharge control circuit and LoRaWAN wireless communication module circuit to realize power supply control and angle calculation of each circuit.

2. A high-precision, low-power LoRaWAN tilt sensor system according to claim 1, characterized in that: The lithium-ion battery management circuit comprises a lithium-ion battery (BT201), a charge and discharge management module and an external power output port (P201); the charge and discharge management module is composed of a charge and discharge management chip (U201), a resistor (R201) and a jumper resistor (R202); the negative electrode of the lithium-ion battery (BT201) is grounded, and the positive electrode is connected to the power supply pin of the charge and discharge management chip (U201) and the external power output port (P201) through a Schottky diode (D201); and the external power output port (P201) is connected to the power switch circuit.

3. A high-precision, low-power LoRaWAN tilt sensor system according to claim 2, characterized in that: The power switch circuit comprises a battery power supply interface (J2) connected to the external power output port (P201) of the lithium-ion battery management circuit, a power input port (P4), a jumper interface (P2), a low-voltage drop anti-reverse connection sub-circuit and an external power switch (J1); the power input port (P4) is connected to the external power switch (J1), the jumper interface (P2) and the low-voltage drop anti-reverse connection sub-circuit respectively through a self-recovery fuse (F1) and an anti-reverse connection dual diode (D1); the jumper interface (P2) is connected in parallel with a jumper resistor (R6).

4. A high-precision, low-power LoRaWAN tilt sensor system according to claim 3, characterized in that: The low voltage drop anti-reverse connection sub-circuit comprises a PMOS tube (Q2) and a resistor (R8), the gate of the PMOS tube (Q2) is grounded through the resistor (R8), the drain is connected to the jumper interface (P2), and the source serves as a power output terminal VDD of the power switch circuit.

5. A high-precision, low-power LoRaWAN tilt sensor system according to claim 1, characterized in that: The temperature sensor circuit comprises a temperature sensor chip (U2), the temperature sensor chip (U2) communicates with a single-chip microcomputer via a single-bus communication interface, and is powered by a GPIO interface of the single-chip microcomputer.

6. A high-precision, low-power LoRaWAN tilt sensor system according to claim 1, characterized in that: The three-axis accelerometer and the power supply and discharge control circuit comprise a three-axis MEMS accelerometer chip (U1) and a power supply and discharge control subcircuit, one end of the power supply and discharge control subcircuit is connected to the accelerometer power supply control pin of the single-chip microcomputer, and the other end is connected to the power supply pin of the three-axis MEMS accelerometer chip (U1), the three-axis MEMS accelerometer chip (U1) is connected and communicated with the single-chip microcomputer via an SPI interface, and the single-chip microcomputer calculates angle data through an inverse tangent algorithm and outputs it.

7. A high-precision, low-power consumption LoRaWAN tilt sensor system according to claim 6, characterized in that: The power supply and discharge control subcircuit is composed of a resistor (R2), a TVS tube (D2) and a capacitor (C3); the accelerometer power supply control pin of the single-chip microcomputer is connected to the power supply end of the three-axis MEMS accelerometer chip (U1) through the resistor (R2); the TVS tube (D2) and the capacitor (C3) are connected in parallel, one end of which is connected between the resistor (R2) and the power supply end of the three-axis MEMS accelerometer chip (U1), and the other end is grounded.

8. A high-precision, low-power LoRaWAN tilt sensor system according to claim 1, characterized in that: The LoRaWAN wireless communication module circuit comprises a LoRaWAN module power supply control subcircuit and a LoRaWAN module subcircuit, wherein the LoRaWAN module power supply control subcircuit comprises a PMOS tube (Q4) and a triode (Q5), wherein the base of the triode (Q5) is connected to the wireless communication module power supply control pin of the single chip microcomputer, the emitter is grounded, the collector is connected to the gate of the PMOS tube (Q4), the drain of the PMOS tube (Q4) is connected to the LoRaWAN module subcircuit, and the source is connected to the output end of the power switch circuit.

9. A high-precision, low-power LoRaWAN tilt sensor system according to claim 8, characterized in that: The LoRaWAN module subcircuit comprises a LoRaWAN module (U5) and an indicator light module, a reset module and an antenna module respectively connected to the LoRaWAN module (U5).

10. A high-precision, low-power LoRaWAN tilt sensor system according to claim 1, characterized in that: The single-chip microcomputer is connected to a crystal oscillator chip (Y1) used by a single-chip microcomputer MCU core and a crystal oscillator chip (Y2) used by a low-power RTC real-time clock module, and different crystal oscillator frequencies are set in working modes corresponding to different workloads to reduce power consumption.

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