Low-power-consumption LoRaWAN tilt angle sensor system installed at any position

Abstract

The invention relates to a low-power-consumption LoRaWAN tilt angle sensor system installed at any position, which is characterized by comprising a single chip microcomputer, a battery discharge management circuit, and a power switch circuit, a temperature sensor circuit, a triaxial accelerometer, a power supply and discharge control circuit and a LoRaWAN wireless communication module circuit which are respectively connected with the single chip microcomputer, and the power switch circuit is respectively connected with the battery discharge management circuit and the LoRaWAN wireless communication module circuit. Compared with the prior art, the invention has the advantages of low power consumption, arbitrary position installation, wide range, uncovering-free starting and the like.

Description

Technical Field

[0001] The present invention relates to the field of sensors, and in particular to a low-power LoRaWAN tilt sensor system that can be installed at any position. Background Art

[0002] The inclination sensor is an instrument used to measure the inclination angle of an object relative to the horizontal plane. It is widely used in industrial automation, engineering construction, automotive safety, aerospace, consumer electronics and other fields. It can help detect the posture and motion state of the device to ensure system stability and accuracy. It uses gravity as a reference. When the sensor is tilted, the gravity component felt by the internal sensitive elements (such as accelerometers or gyroscopes) changes, and then the inclination angle is calculated.

[0003] At present, the three-axis inclination sensor with a three-axis measurement range of ±90° has restrictions on the installation direction and needs to be opened for power-on, which makes the installation inconvenient. In addition, there are 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 low-power LoRaWAN tilt sensor system that can be installed at any position, characterized in that the system includes a single-chip microcomputer, a battery discharge management circuit, and a power switch circuit, a temperature sensor circuit, a three-axis accelerometer and a power supply and discharge control circuit and a LoRaWAN wireless communication module circuit respectively connected to the single-chip microcomputer, and the power switch circuit is respectively connected to the battery discharge management circuit and the LoRaWAN wireless communication module circuit.

[0005] Furthermore, the battery discharge 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.

[0006] Furthermore, the battery discharge management circuit also includes a composite pulse capacitor, one end of which is grounded, and the other end of which is connected between the Schottky diode and a power supply pin of the charge and discharge management chip.

[0007] Furthermore, the power switch circuit includes a battery power supply interface connected to the external power output port, a reverse polarity protection dual diode and a debugging power input port, pin 1 of the reverse polarity protection dual diode is connected to the debugging power input port through a resettable fuse, pin 2 is connected to the battery power supply interface, and pin 3 is connected to the power output terminal VDD of the power switch circuit.

[0008] 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.

[0009] Furthermore, the three-axis accelerometer and the power supply and discharge control circuit include a three-axis MEMS accelerometer chip 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. The three-axis MEMS accelerometer chip adopts I 2 The C interface is connected to the single-chip microcomputer for communication. The single-chip microcomputer calculates angle data through an inverse tangent algorithm and outputs the angle data.

[0010] 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.

[0011] 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 collector is grounded, the emitter is connected to the gate of the PMOS tube, the source of the PMOS tube is connected to the LoRaWAN module subcircuit, and the drain is connected to the output end of the power switch circuit.

[0012] 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.

[0013] Furthermore, the system also includes a cover-free starting module, which includes a Hall switch circuit and a magnet respectively connected to the power switch circuit and the single-chip microcomputer, and the Hall switch circuit includes at least one Hall switch chip. The Hall switch chip is triggered by the magnet to output and send to the single-chip microcomputer, and the single-chip microcomputer realizes cover-free starting according to a preset trigger sequence and count.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. Low power consumption: The present invention designs switch control circuits for the LoRaWAN module and the three-axis accelerometer respectively. When the tilt sensor system enters the sleep state, the single-chip microcomputer can turn off the power supply of all peripherals and adopt a periodic wake-up strategy, which greatly reduces the sleep power consumption. The power consumption is reduced to only 10uA during sleep.

[0016] 2. Installation at any position: The present invention adopts a three-axis MEMS accelerometer chip, supports three-axis synchronous sampling, adopts a three-axis inverse tangent algorithm for angle calculation, and three-axis measurement and three-axis angle output, ensuring the inclination detection capability of the inclination sensor product in any installation direction, thus solving the limitation of the existing inclination sensors in installation direction.

[0017] 3. Large range: The present invention uses a three-axis MEMS accelerometer to detect static tilt angles. The current technology is to obtain the tilt angle value by performing an inverse sine function operation on the gravity acceleration component on a certain axis of the accelerometer. According to the characteristics of the sine curve, the larger the angle, the worse the linearity of the acceleration and angle. Therefore, this method is more suitable for small-range calculations. However, as the angle increases, the calculated angle accuracy gradually deteriorates. The present invention uses a three-axis inverse tangent algorithm to solve the angle, achieving a measurement accuracy of 0.5° within a range of ±90°.

[0018] 4. Starting without opening the cover: The present invention designs a Hall switch circuit to trigger the low-power pulse counting module PCNT of the single-chip microcomputer, thereby realizing low-power magnet starting without opening the cover for a certain number of times and triggering sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a circuit principle block diagram of the present invention;

[0020] Figure 2 The circuit schematic diagram of the battery discharge management circuit;

[0021] Figure 3 is a circuit schematic diagram of a power switch circuit;

[0022] Figure 4 is the circuit schematic diagram of the temperature sensor circuit;

[0023] Figure 5 It is the circuit schematic diagram of the three-axis accelerometer and the power supply and discharge control circuit;

[0024] Figure 6 It is the circuit schematic diagram of the single chip microcomputer and peripheral circuits;

[0025] Figure 7a Circuit diagram of the power supply control subcircuit for the LoRaWAN module;

[0026] Figure 7b This is the circuit schematic diagram of the LoRaWAN module subcircuit;

[0027] Figure 8a is the circuit schematic diagram of the key sub-circuit;

[0028] Figure 8b It is the circuit schematic diagram of the indicator light sub-circuit;

[0029] Fig. 9 This is the circuit schematic diagram of the Hall switch circuit;

[0030] Fig.10 It is a flow chart of the working principle of the present invention;

[0031] Fig.11 This is the flow chart of angle calculation and calibration. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0036] 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.

[0037] In order 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.

[0038] Example

[0039] like Figure 1 As shown, the present invention provides a low-power LoRaWAN tilt sensor system that can be installed at any position, which is used to achieve three-axis angle output through three-axis angle calculation and six-position calibration, and can achieve low power consumption and start-up without opening the cover. The system includes a single-chip microcomputer, a battery discharge management circuit, and 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, a button and indicator light circuit, and a Hall switch circuit respectively connected to the single-chip microcomputer.

[0040] like Figure 2 As shown, the battery discharge 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.

[0041] 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 module 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.

[0042] 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 DW02KA in this example). At the same time, it can also carry large currents in a short period of time such as wireless communications.

[0043] like Figure 3As shown, in the power switch circuit, P4 is the power input port used for debugging, D5 is an anti-reverse polarity dual diode, which provides independent anti-reverse polarity protection for the two power supply interfaces, F1 is a self-recovering fuse, which is set between the power input port P4 and the anti-reverse polarity dual diode D5 to prevent overcurrent, J2 is a battery power supply interface, which is connected to the external power output port P201 through a wire, and the power output end is VDD.

[0044] like Figure 4 As shown, in the temperature sensor circuit, the high-precision temperature sensor chip U2 (model M1820P in this example) uses a single-bus communication interface to communicate with the single-chip microcomputer, and the power supply is controlled by the GPIO interface of the single-chip microcomputer. The power supply is only supplied when in use, and the power supply is turned off when not in use to reduce power consumption. The high-precision temperature sensor chip U2 is used to detect the current temperature of the inclination sensor system for temperature compensation.

[0045] like Figure 5 As shown, in the three-axis accelerometer and the power supply and discharge control circuit, the resistor R4, the TVS tube D2, and the capacitor C3 form a power supply and discharge control circuit for the three-axis accelerometer directly controlled by the single-chip microcomputer, and the power supply is turned on only when the three-axis accelerometer is used, and it is turned off to save power when not in use. The accelerometer power supply control pin ACC_POWER of the single-chip microcomputer is connected to the power supply end of the three-axis accelerometer through the resistor R4, and the TVS tube D2 and the capacitor C3 are connected in parallel, one end is connected between the resistor R4 and the power supply end of the three-axis accelerometer, and the other end is grounded.

[0046] In the present invention, a three-axis MEMS accelerometer chip U10 (in this example, the model is ICM-42370-P) is used as the core device of the tilt sensor. The capacitors around the three-axis MEMS accelerometer chip U10 are its power supply bypass and decoupling capacitors. The three-axis MEMS accelerometer chip U10 is connected to the I 2 C interface to communicate with the microcontroller.

[0047] like Figure 6 As shown, in the single-chip microcomputer and peripheral circuits, Y1 and Y2 are external crystal oscillator chips respectively, among which 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 the 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, and the peripheral devices are its minimum system. J3 is the SWD program burning and debugging interface, and 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, thereby realizing data collection of chips such as the three-axis MEMS accelerometer chip U10 and the high-precision temperature sensor chip U2, as well as the calculation of data such as angle and temperature.

[0048] For example, when the tilt sensor system is in alarm detection mode (non-sleep mode), it only needs to detect whether it exceeds the alarm angle. At this time, the main frequency of the microcontroller can be reduced to 1MHz. When data needs to be transmitted and sent, the main frequency of the microcontroller can be appropriately increased to 16MHz.

[0049] The LoRaWAN wireless communication module circuit includes a LoRaWAN module power supply control subcircuit and a LoRaWAN module 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 collector is grounded, the emitter is connected to the gate of PMOS tube Q4, the source of PMOS tube Q4 is connected to the LoRaWAN module U5, and the drain 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.

[0050] like Figure 7b As shown, the LoRaWAN module subcircuit includes 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; the reset module includes a reset capacitor C33 and a reset resistor R29, and the output end 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.

[0051] 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 manually triggered 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 sequence. 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 8bAs 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. Neither the button sub-circuit nor the indicator light sub-circuit will generate power consumption in the sleep state, which can further achieve low power consumption.

[0052] At present, the product assembly steps including batteries have been completed before the inclination sensor products leave the factory. In order to reduce the power consumption of the inclination sensor products during transportation and ensure the service life of the batteries, the inclination sensor products will be set to transportation mode when leaving the factory, that is, the product enters a low power consumption mode. Unlike the sleep state, this low power consumption mode will not be actively awakened, which is used to prevent the inclination sensor products from waking up due to false triggering and other reasons during transportation and then trying to access the network and generate power consumption. After the user receives the inclination sensor product, the product needs to be activated to exit the transportation mode.

[0053] Since existing inclination sensor products are activated by a push button switch, in order to avoid the risk of the inclination sensor products being accidentally activated during transportation, and to save users the trouble of opening the cover to start the inclination sensor product before use after receiving it, the present invention designs a start switch, and the user only needs to use the start switch to activate the product.

[0054] The present invention designs an activation method using a single-chip microcomputer PCNT (in this example, a Huada pulse counting module PCNT) and an external device in conjunction with a start switch. In this example, the start switch includes a Hall switch circuit and an external trigger device, such as Fig. 9 As shown, the Hall switch circuit includes Hall switch chips U7 and U8, and the peripheral capacitors are decoupling capacitors. The average operating current of the Hall switch chip is only 2uA, which achieves low power consumption. The external trigger device is usually an external magnet. When the tilt sensor product is activated, the external magnet is brought close to the Hall switch chip, and the output of the Hall switch chip will flip, which will be acquired by the single-chip microcomputer PCNT and sent to the single-chip microcomputer (pins 23 and 30 of the single-chip microcomputer chip U3) for counting. The present invention uses two Hall switch chips (one or more can be set according to actual needs, corresponding to different trigger times and sequences), and the trigger times and trigger sequences of the two Hall switch chips are pre-set in the single-chip microcomputer. When the external magnet is triggered in a preset manner (for example, sliding across the two Hall switch chips from left to right in sequence, etc.), low-power activation and start-up without opening the cover can be achieved.

[0055] like Fig.10As shown, the present invention implements a low-precision, arbitrarily installed, magnet-started, low-power LoRaWAN inclination sensor. Therefore, 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 accelerometers, temperature sensors and other components are completed. After entering the main loop, the watchdog is first fed, 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 inclination sensor will enter a low-power sleep state. The low-power pulse counting module PCNT inside the single-chip microcomputer will count the level changes of the Hall switch, and when the preset conditions are reached, it will trigger the wake-up of the single-chip microcomputer and enter the subsequent process. 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.

[0056] like Fig.11 As shown, the angle calculation and calibration process of the present invention is firstly performed by the single chip microcomputer through I 2 The C interface samples the three-axis accelerometer, and then filters the collected original values ​​to remove high-frequency noise and jitter. Subsequently, the six-position calibration algorithm is applied to the filtered acceleration values ​​for installation alignment error, cross-axis and sensitivity preliminary calibration. The three-axis inverse tangent algorithm is then used to solve the angle, and finally the factory zero point calibration is performed. At this point, the entire angle solution and calibration process is completed. The LoRaWAN inclination sensor of the present invention can achieve an accuracy requirement of 0.5° when installed on any six surfaces.

[0057] 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 low-power LoRaWAN tilt sensor system installed at any position, characterized in that: The system includes a single-chip microcomputer, a battery discharge management circuit, and a power switch circuit, a temperature sensor circuit, a three-axis accelerometer, a power supply and discharge control circuit, and a LoRaWAN wireless communication module circuit respectively connected to the single-chip microcomputer. The power switch circuit is respectively connected to the battery discharge management circuit and the LoRaWAN wireless communication module circuit.

2. A low-power LoRaWAN tilt sensor system installed at any position according to claim 1, characterized in that: The battery discharge 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 low-power LoRaWAN tilt sensor system installed at any position according to claim 2, characterized in that: The battery discharge management circuit also includes a composite pulse capacitor (C201), one end of the composite pulse capacitor (C201) is grounded, and the other end is connected between the Schottky diode (D201) and the power supply pin of the charge and discharge management chip (U201).

4. A low-power LoRaWAN tilt sensor system installed at any position 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), a reverse connection protection dual diode (D5) and a debugging power input port (P4), wherein pin 1 of the reverse connection protection dual diode (D5) is connected to the debugging power input port (P4) via a resettable fuse (F1), pin 2 is connected to the battery power supply interface (J2), and pin 3 is connected to a power output terminal VDD of the power switch circuit.

5. A low-power LoRaWAN tilt sensor system installed at any position 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 low-power LoRaWAN tilt sensor system installed at any position 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 (U10) 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 (U10), and the three-axis MEMS accelerometer chip (U10) adopts I 2 The C interface is connected to the single-chip microcomputer for communication. The single-chip microcomputer calculates angle data through an inverse tangent algorithm and outputs the angle data.

7. A low-power LoRaWAN tilt sensor system installed at any position 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.

8. A low-power LoRaWAN tilt sensor system installed at any position 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 collector is grounded, the emitter is connected to the gate of the PMOS tube (Q4), the source of the PMOS tube (Q4) is connected to the LoRaWAN module subcircuit, and the drain is connected to the output end of the power switch circuit.

9. A low-power LoRaWAN tilt sensor system installed at any position according to claim 1, 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 low-power LoRaWAN tilt sensor system installed at any position according to claim 1, characterized in that: The system also includes a cover-free startup module, which includes a Hall switch circuit and a magnet respectively connected to the power switch circuit and the single-chip microcomputer. The Hall switch circuit includes at least one Hall switch chip. The Hall switch chip triggers the output through the magnet and sends it to the single-chip microcomputer. The single-chip microcomputer realizes cover-free startup according to a preset trigger sequence and count.

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