Digital inclinometer

Abstract

The utility model discloses a digital inclinometer, which belongs to the technical field of instruments and meters and comprises a main controller, a first AD (analog-to-digital) module, a second AD module, a wireless communication module, a 485 module, a key group, an LCD (liquid crystal display) screen, a first inclination angle measuring unit, a second inclination angle measuring unit, a third inclination angle measuring unit, a fourth inclination angle measuring unit and a power supply module, the technical problem of four-channel inclination angle data acquisition with high precision and high anti-interference performance is solved, the four-channel inclination angle measuring device is provided with four inclination angle measuring units, angles of four different positions can be measured at the same time, the requirement of multi-channel measurement is met, digital processing is carried out on analog signals by adopting a 12-bit AD module, the acquisition precision is ensured, the cost is reduced, and the acquisition efficiency is improved. And the wireless communication module and the 485 module are arranged, so that data transmission and communication with external equipment are realized, and the flexibility and expansibility of the system are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of instruments and meters, and particularly relates to a digital inclinometer. Background Art

[0002] Electronic inclination measuring instruments usually use inclination sensors to measure inclination. Their working principle is to collect inclination information through sensors and then display or record it through digital displays or analog meters. However, this traditional electronic inclination measuring instrument still has the following shortcomings:

[0003] 1. Traditional electronic inclinometers are subject to high-frequency and low-frequency interference coupled to the power line, which affects the stability of the acquisition circuit and thus affects the measurement accuracy;

[0004] 2. Traditional electronic inclination measuring instruments can usually only measure the inclination information of a single channel and cannot obtain data from multiple channels at the same time, which limits their application in multi-channel monitoring and control systems. Utility Model Content

[0005] The utility model aims to provide a digital inclinometer, which solves the technical problem of 4-channel high-interference-resistance inclination data collection.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A digital inclinometer, comprising a main controller, a first AD module, a second AD module, a wireless communication module, a 485 module, a key group, an LCD display screen, a first inclination measuring unit, a second inclination measuring unit, a third inclination measuring unit, a fourth inclination measuring unit and a power module;

[0008] The first inclination measurement unit and the second inclination measurement unit are both connected to the first AD module, and the third inclination measurement unit and the fourth inclination measurement unit are both connected to the second AD module;

[0009] The first AD module, the second AD module, the wireless communication module, the 485 module, the button group and the LCD display screen are all connected to the main controller;

[0010] The first inclination angle measuring unit comprises a first sensor, a filter circuit A, a filter circuit B, a first adjustable gain amplifier and a first active filter, the positive output end of the first sensor is connected to the filter circuit A, the negative output end is connected to the filter circuit B, the filter circuit A and the filter circuit B are respectively connected to the positive input end and the negative input end of the first adjustable gain amplifier, the output end of the first adjustable gain amplifier is connected to the first active filter, and the first active filter is connected to the first AD module;

[0011] The second inclination angle measuring unit comprises a second sensor, a filter circuit C, a filter circuit D, a second adjustable gain amplifier and a second active filter, the positive output end of the second sensor is connected to the filter circuit C, the negative output end is connected to the filter circuit D, the filter circuit C and the filter circuit D are respectively connected to the positive input end and the negative input end of the second adjustable gain amplifier, the output end of the second adjustable gain amplifier is connected to the second active filter, and the second active filter is connected to the first AD module;

[0012] The third inclination angle measuring unit comprises a third sensor, a filter circuit E, a filter circuit F, a third adjustable gain amplifier and a third active filter, the positive output end of the third sensor is connected to the filter circuit E, the negative output end is connected to the filter circuit F, the filter circuit E and the filter circuit F are respectively connected to the positive input end and the negative input end of the third adjustable gain amplifier, the output end of the third adjustable gain amplifier is connected to the third active filter, and the third active filter is connected to the second AD module;

[0013] The fourth inclination measurement unit includes a fourth sensor, a filter circuit G, a filter circuit H, a fourth adjustable gain amplifier and a fourth active filter, the positive output end of the fourth sensor is connected to the filter circuit G, the negative output end is connected to the filter circuit H, the filter circuit G and the filter circuit H are respectively connected to the positive input end and the negative input end of the fourth adjustable gain amplifier, the output end of the fourth adjustable gain amplifier is connected to the fourth active filter, and the fourth active filter is connected to the second AD module;

[0014] The power module supplies power to the main controller, the first AD module, the second AD module, the wireless communication module, the 485 module, the button group, the LCD display screen, the first inclination measurement unit, the second inclination measurement unit, the third inclination measurement unit, and the fourth inclination measurement unit.

[0015] Preferably, the models of the first AD module and the second AD module are both ADS1013, the model of the main controller is STM32F429, the model of the LCD display is ILI9341 2.8" TFT LCD, the models of the first sensor, the second sensor, the third sensor and the fourth sensor are all SCA103T inclination sensors, the model of the 485 module is MAX485, and the model of the wireless communication module is HC12.

[0016] Preferably, the power supply module includes a 24VACDC module, a positive and negative 15V voltage regulator, a 5V voltage regulator and a 3.3V voltage regulator. The input end of the 24VACDC module is connected to the AC power supply, and the output end is connected to the positive and negative 15V voltage regulator. The output ends of the positive and negative 15V voltage regulators output positive 15V power supply and negative 15V power supply respectively. The input end of the 5V voltage regulator is connected to the positive 15V power supply, and the output end outputs 5V power supply. The input end of the 5V power supply is connected to the positive 15V power supply, and the output end outputs 5V power supply. The input end of the 3.3V voltage regulator is connected to the 5V power supply, and the output end outputs 3.3V power supply.

[0017] Preferably, the main controller, the first AD module, the second AD module, the wireless communication module, the 485 module and the LCD display are all powered by a 3.3V power supply;

[0018] The first sensor, the second sensor, the third sensor and the fourth sensor are all powered by a 5V power supply;

[0019] The first adjustable gain amplifier, the first active filter, the second adjustable gain amplifier, the second active filter, the third adjustable gain amplifier, the third active filter, the fourth adjustable gain amplifier and the fourth active filter are all powered by a positive 15V power supply and a negative 15V power supply.

[0020] Preferably, the first sensor includes a sensor U1, the OUT1 pin of the sensor U1 is the positive output terminal of the first sensor, the OUT2 pin is the negative output terminal of the first sensor, the filter circuit A includes a resistor R2, a capacitor C5, a capacitor C6 and a capacitor C7, the filter circuit B includes a resistor R1, a capacitor C1, a capacitor C3 and a capacitor C4, and the first adjustable gain amplifier includes an amplifier OP1, a resistor R3, a resistor R4, a transistor Q1, a transistor Q2, a field effect transistor Q3, a field effect transistor Q4, a resistor R3, a group R4, a resistor R18, a resistor R5, a resistor R15, a resistor R16, resistor R17, resistor R20, resistor R6 and resistor R21, the OUT1 pin of the sensor U1 is connected to the 2nd pin of the transistor Q1 through the resistor R2, the OUT2 pin is connected to the 2nd pin of the transistor Q2 through the resistor R1, one end of the capacitor C5 is connected to the connection node between the resistor R2 and the 2nd pin of the transistor Q1, and the other end is connected to the ground line, capacitors C6 and C7 are filter capacitors of the 2nd pin of the transistor Q1, one end of the capacitor C1 is connected to the connection node between the resistor R1 and the 2nd pin of the transistor Q2, and the other end is connected to the ground line, capacitors C3 and C4 are filter capacitors of the 2nd pin of the transistor Q2;

[0021] Pin 1 of transistor Q1 is connected to a positive 15V power supply through resistor R3, pin 1 of transistor Q2 is connected to a positive 15V power supply through resistor R4, the positive input terminal of amplifier OP1 is connected to pin 1 of transistor Q2, and the negative input terminal is connected to pin 1 of transistor Q1, pin 3 of transistor Q1 is connected to the D pole of field effect transistor Q3 through resistor R18, the S pole of field effect transistor Q3 is connected to the negative 15V power supply through resistor R17, the G pole is connected to the ground wire through resistor R15, the G pole of field effect transistor Q3 is connected to the negative 15V power supply through resistor R16, pin 3 of transistor Q2 is connected to the D pole of field effect transistor Q4 through resistor R5, the S pole of field effect transistor Q4 is connected to the negative 15V power supply through resistor R20, the G pole is connected to the negative 15V power supply through resistor R21, the G pole of field effect transistor Q4 is also connected to the output terminal of amplifier OP1 through resistor R6, one end of resistor R19 is connected to the D pole of field effect transistor Q3, and the other end is connected to the D pole of field effect transistor Q4;

[0022] The first active filter comprises an amplifier OP2, a capacitor C8, a resistor R8, a capacitor C9, a resistor R7, a resistor R9 and a resistor R10, wherein the output end of the amplifier OP1 is connected to one end of the resistor R9 through the resistor R7, wherein the pin 2 of the resistor R7 is connected to the resistor R9, the other end of the resistor R9 is connected to the ground line through the resistor R10, the connection node between the resistor R9 and the resistor R10 is connected to an AD input end of the first AD module, the pin 2 of the resistor R7 is connected to the positive electrode of the capacitor C8, the negative electrode of the capacitor C8 is connected to the negative input end of the amplifier OP2, the positive input end of the amplifier OP2 is connected to the ground line, the output end is connected to the positive electrode of the capacitor C9, the negative electrode of the capacitor C9 is connected to the pin 2 of the resistor R7, and the resistor R8 is connected between the negative input end and the output end of the amplifier OP2;

[0023] The circuit principles of the second inclination measurement unit, the third inclination measurement unit and the fourth inclination measurement unit are the same as the circuit principle of the first inclination measurement unit.

[0024] The digital inclinometer described in the utility model solves the technical problem of 4-channel high-precision and high-interference resistance inclination data acquisition. The utility model has four inclination measurement units, which can measure the angles of four different positions at the same time, meeting the needs of multi-channel measurement, and adopts a 12-bit AD module to digitize the analog signal, thereby ensuring the acquisition accuracy while reducing the cost. It is equipped with a wireless communication module and a 485 module, realizing data transmission and communication with external equipment, and improving the flexibility and expansibility of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic block diagram of the utility model;

[0026] Figure 2 It is a circuit diagram of the first inclination angle measuring unit of the utility model;

[0027] Figure 3 It is a circuit diagram of the first AD module and the second AD module of the utility model. DETAILED DESCRIPTION

[0028] Depend on Figure 1-3 A digital inclinometer shown includes a main controller, a first AD module, a second AD module, a wireless communication module, a 485 module, a key group, an LCD display screen, a first inclination measuring unit, a second inclination measuring unit, a third inclination measuring unit, a fourth inclination measuring unit and a power module;

[0029] The first inclination measurement unit and the second inclination measurement unit are both connected to the first AD module, and the third inclination measurement unit and the fourth inclination measurement unit are both connected to the second AD module;

[0030] The first AD module, the second AD module, the wireless communication module, the 485 module, the button group and the LCD display screen are all connected to the main controller;

[0031] The first inclination angle measuring unit comprises a first sensor, a filter circuit A, a filter circuit B, a first adjustable gain amplifier and a first active filter, the positive output end of the first sensor is connected to the filter circuit A, the negative output end is connected to the filter circuit B, the filter circuit A and the filter circuit B are respectively connected to the positive input end and the negative input end of the first adjustable gain amplifier, the output end of the first adjustable gain amplifier is connected to the first active filter, and the first active filter is connected to the first AD module;

[0032] The first sensor includes a sensor U1, wherein the OUT1 pin of the sensor U1 is a positive output terminal of the first sensor, and the OUT2 pin is a negative output terminal of the first sensor, the filter circuit A includes a resistor R2, a capacitor C5, a capacitor C6 and a capacitor C7, the filter circuit B includes a resistor R1, a capacitor C1, a capacitor C3 and a capacitor C4, and the first adjustable gain amplifier includes an amplifier OP1, a resistor R3, a resistor R4, a transistor Q1, a transistor Q2, a field effect transistor Q3, a field effect transistor Q4, a resistor R3, a bandgap R4, a resistor R18, a resistor R5, a resistor R15, and a resistor R1 6. Resistor R17, resistor R20, resistor R6 and resistor R21, the OUT1 pin of the sensor U1 is connected to the 2nd pin of the transistor Q1 through the resistor R2, the OUT2 pin is connected to the 2nd pin of the transistor Q2 through the resistor R1, one end of the capacitor C5 is connected to the connection node between the resistor R2 and the 2nd pin of the transistor Q1, and the other end is connected to the ground line, capacitors C6 and C7 are filter capacitors of the 2nd pin of the transistor Q1, one end of the capacitor C1 is connected to the connection node between the resistor R1 and the 2nd pin of the transistor Q2, and the other end is connected to the ground line, capacitors C3 and C4 are filter capacitors of the 2nd pin of the transistor Q2;

[0033] Pin 1 of transistor Q1 is connected to a positive 15V power supply through resistor R3, pin 1 of transistor Q2 is connected to a positive 15V power supply through resistor R4, the positive input terminal of amplifier OP1 is connected to pin 1 of transistor Q2, and the negative input terminal is connected to pin 1 of transistor Q1, pin 3 of transistor Q1 is connected to the D pole of field effect transistor Q3 through resistor R18, the S pole of field effect transistor Q3 is connected to the negative 15V power supply through resistor R17, the G pole is connected to the ground wire through resistor R15, the G pole of field effect transistor Q3 is connected to the negative 15V power supply through resistor R16, pin 3 of transistor Q2 is connected to the D pole of field effect transistor Q4 through resistor R5, the S pole of field effect transistor Q4 is connected to the negative 15V power supply through resistor R20, the G pole is connected to the negative 15V power supply through resistor R21, the G pole of field effect transistor Q4 is also connected to the output terminal of amplifier OP1 through resistor R6, one end of resistor R19 is connected to the D pole of field effect transistor Q3, and the other end is connected to the D pole of field effect transistor Q4;

[0034] The first active filter comprises an amplifier OP2, a capacitor C8, a resistor R8, a capacitor C9, a resistor R7, a resistor R9 and a resistor R10, wherein the output end of the amplifier OP1 is connected to one end of the resistor R9 through the resistor R7, wherein the pin 2 of the resistor R7 is connected to the resistor R9, the other end of the resistor R9 is connected to the ground line through the resistor R10, the connection node between the resistor R9 and the resistor R10 is connected to an AD input end of the first AD module, the pin 2 of the resistor R7 is connected to the positive electrode of the capacitor C8, the negative electrode of the capacitor C8 is connected to the negative input end of the amplifier OP2, the positive input end of the amplifier OP2 is connected to the ground line, the output end is connected to the positive electrode of the capacitor C9, the negative electrode of the capacitor C9 is connected to the pin 2 of the resistor R7, and the resistor R8 is connected between the negative input end and the output end of the amplifier OP2;

[0035] The models of the first AD module and the second AD module are both ADS1013, the model of the main controller is STM32F429, the model of the LCD display is ILI9341 2.8" TFT LCD, the models of the first sensor, the second sensor, the third sensor and the fourth sensor are all SCA103T inclination sensors, the model of the 485 module is MAX485, and the model of the wireless communication module is HC12.

[0036] In this embodiment, the analog output terminal of the SCA103T tilt sensor is selected as the signal output terminal, and the corresponding tilt analog signal is obtained, so that the utility model can obtain a wider operating voltage range and a higher signal bandwidth.

[0037] The positive and negative output signals of the SCA103T inclination sensor are first low-pass filtered by filter circuit A and filter circuit B, and then sent to the first adjustable gain amplifier. The first adjustable gain amplifier is an adjustable gain amplifier and a high-input impedance differential amplifier, which can well suppress the high-frequency and low-frequency interference coupled to the power line and obtain a stable inclination analog signal. The gain can be adjusted by adjusting the resistor R19. Filter circuit A and filter circuit B are also respectively provided with high-frequency filter capacitors to filter out the high-frequency signal interference generated by the 433 module transmission. Usually, a capacitor between 10p and 100p can be used.

[0038] In this embodiment, the transistor Q1 and the transistor Q2 may be 2N5520, the field effect transistor Q3 and the field effect transistor Q4 may be IRF9540, the amplifier OP1 may be LM208, and the amplifier OP2 may be uA741.

[0039] In the actual debugging process, the first inclination angle measurement unit can be taken out as an independent unit for testing. The user can set a test point at pin 2 of resistor R7 and use an oscilloscope to check the stability and anti-interference of its output to facilitate generation.

[0040] The output of the first adjustable gain amplifier is connected to the first AD module after voltage division by resistors R9 and R10. In this embodiment, the first AD module is AD chip U2, the second AD module is AD chip U3, and the first AD module communicates with the main controller through the I2C bus.

[0041] The first active filter is a fast-response active filter, which is composed of an amplifier OP2 and can filter the output signal of the first adjustable gain amplifier well, and further remove power supply interference.

[0042] In this embodiment, the main controller adopts STM32F429, which has an integrated LCD-TFT controller and can directly drive the LCD display screen, reducing the complexity of circuit design.

[0043] The second inclination angle measuring unit comprises a second sensor, a filter circuit C, a filter circuit D, a second adjustable gain amplifier and a second active filter, the positive output end of the second sensor is connected to the filter circuit C, the negative output end is connected to the filter circuit D, the filter circuit C and the filter circuit D are respectively connected to the positive input end and the negative input end of the second adjustable gain amplifier, the output end of the second adjustable gain amplifier is connected to the second active filter, and the second active filter is connected to the first AD module;

[0044] The third inclination angle measuring unit comprises a third sensor, a filter circuit E, a filter circuit F, a third adjustable gain amplifier and a third active filter, the positive output end of the third sensor is connected to the filter circuit E, the negative output end is connected to the filter circuit F, the filter circuit E and the filter circuit F are respectively connected to the positive input end and the negative input end of the third adjustable gain amplifier, the output end of the third adjustable gain amplifier is connected to the third active filter, and the third active filter is connected to the second AD module;

[0045] The fourth inclination measurement unit includes a fourth sensor, a filter circuit G, a filter circuit H, a fourth adjustable gain amplifier and a fourth active filter. The positive output end of the fourth sensor is connected to the filter circuit G, and the negative output end is connected to the filter circuit H. The filter circuit G and the filter circuit H are respectively connected to the positive input end and the negative input end of the fourth adjustable gain amplifier. The output end of the fourth adjustable gain amplifier is connected to the fourth active filter, and the fourth active filter is connected to the second AD module.

[0046] The circuit principles of the second inclination measurement unit, the third inclination measurement unit and the fourth inclination measurement unit are the same as the circuit principle of the first inclination measurement unit.

[0047] The utility model adopts two AD chips as digital-to-analog converters of four-channel inclination angle data, which can save the demand for the IO ports of the main controller and reduce the complexity of software design.

[0048] The power module supplies power to the main controller, the first AD module, the second AD module, the wireless communication module, the 485 module, the button group, the LCD display, the first inclination measurement unit, the second inclination measurement unit, the third inclination measurement unit, and the fourth inclination measurement unit;

[0049] The power supply module includes a 24VACDC module, a positive and negative 15V voltage regulator, a 5V voltage regulator and a 3.3V voltage regulator. The input end of the 24VACDC module is connected to the mains, and the output end is connected to the positive and negative 15V voltage regulator. The output end of the positive and negative 15V voltage regulator outputs a positive 15V power supply and a negative 15V power supply respectively. The input end of the 5V voltage regulator is connected to the positive 15V power supply, and the output end outputs a 5V power supply. The input end of the 5V power supply is connected to the positive 15V power supply, and the output end outputs a 5V power supply. The input end of the 3.3V voltage regulator is connected to the 5V power supply, and the output end outputs a 3.3V power supply.

[0050] In this embodiment, the model of the 24VACDC module is IRM-30-24ST, the positive and negative 15V regulators are a pair of three-terminal regulators, including LM7815 / LM7915, which output positive 15V and negative 15V power supplies respectively, the model of the 5V regulator is LM7805, and the model of the 3.3V regulator is AMS1117-3.3.

[0051] The main controller, the first AD module, the second AD module, the wireless communication module, the 485 module and the LCD display are all powered by a 3.3V power supply;

[0052] The first sensor, the second sensor, the third sensor and the fourth sensor are all powered by a 5V power supply;

[0053] The first adjustable gain amplifier, the first active filter, the second adjustable gain amplifier, the second active filter, the third adjustable gain amplifier, the third active filter, the fourth adjustable gain amplifier and the fourth active filter are all powered by a positive 15V power supply and a negative 15V power supply.

[0054] The digital inclinometer described in the utility model solves the technical problem of 4-channel high-precision and high-interference resistance inclination data acquisition. The utility model has four inclination measurement units, which can measure the angles of four different positions at the same time, meeting the needs of multi-channel measurement, and adopts a 12-bit AD module to digitize the analog signal, thereby ensuring the acquisition accuracy while reducing the cost. It is equipped with a wireless communication module and a 485 module, realizing data transmission and communication with external equipment, and improving the flexibility and expansibility of the system.

Claims

1. A digital inclinometer, characterized in that: It includes a main controller, a first AD module, a second AD module, a wireless communication module, a 485 module, a button group, an LCD display screen, a first inclination measuring unit, a second inclination measuring unit, a third inclination measuring unit, a fourth inclination measuring unit and a power module; The first inclination measurement unit and the second inclination measurement unit are both connected to the first AD module, and the third inclination measurement unit and the fourth inclination measurement unit are both connected to the second AD module; The first AD module, the second AD module, the wireless communication module, the 485 module, the button group and the LCD display screen are all connected to the main controller; The first inclination angle measuring unit comprises a first sensor, a filter circuit A, a filter circuit B, a first adjustable gain amplifier and a first active filter, the positive output end of the first sensor is connected to the filter circuit A, the negative output end is connected to the filter circuit B, the filter circuit A and the filter circuit B are respectively connected to the positive input end and the negative input end of the first adjustable gain amplifier, the output end of the first adjustable gain amplifier is connected to the first active filter, and the first active filter is connected to the first AD module; The second inclination angle measuring unit comprises a second sensor, a filter circuit C, a filter circuit D, a second adjustable gain amplifier and a second active filter, the positive output end of the second sensor is connected to the filter circuit C, the negative output end is connected to the filter circuit D, the filter circuit C and the filter circuit D are respectively connected to the positive input end and the negative input end of the second adjustable gain amplifier, the output end of the second adjustable gain amplifier is connected to the second active filter, and the second active filter is connected to the first AD module; The third inclination angle measuring unit comprises a third sensor, a filter circuit E, a filter circuit F, a third adjustable gain amplifier and a third active filter, the positive output end of the third sensor is connected to the filter circuit E, the negative output end is connected to the filter circuit F, the filter circuit E and the filter circuit F are respectively connected to the positive input end and the negative input end of the third adjustable gain amplifier, the output end of the third adjustable gain amplifier is connected to the third active filter, and the third active filter is connected to the second AD module; The fourth inclination measurement unit includes a fourth sensor, a filter circuit G, a filter circuit H, a fourth adjustable gain amplifier and a fourth active filter, the positive output end of the fourth sensor is connected to the filter circuit G, the negative output end is connected to the filter circuit H, the filter circuit G and the filter circuit H are respectively connected to the positive input end and the negative input end of the fourth adjustable gain amplifier, the output end of the fourth adjustable gain amplifier is connected to the fourth active filter, and the fourth active filter is connected to the second AD module; The power module supplies power to the main controller, the first AD module, the second AD module, the wireless communication module, the 485 module, the button group, the LCD display screen, the first inclination measurement unit, the second inclination measurement unit, the third inclination measurement unit, and the fourth inclination measurement unit.

2. A digital inclinometer as claimed in claim 1, characterized in that: The models of the first AD module and the second AD module are both ADS1013, the model of the main controller is STM32F429, the model of the LCD display is ILI93412.8" TFT LCD, the models of the first sensor, the second sensor, the third sensor and the fourth sensor are all SCA103T inclination sensors, the model of the 485 module is MAX485, and the model of the wireless communication module is HC12.

3. A digital inclinometer as claimed in claim 1, characterized in that: The power supply module includes a 24VACDC module, a positive and negative 15V voltage regulator, a 5V voltage regulator and a 3.3V voltage regulator. The input end of the 24VACDC module is connected to the mains, and the output end is connected to the positive and negative 15V voltage regulator. The output end of the positive and negative 15V voltage regulator outputs a positive 15V power supply and a negative 15V power supply respectively. The input end of the 5V voltage regulator is connected to the positive 15V power supply, and the output end outputs a 5V power supply. The input end of the 5V power supply is connected to the positive 15V power supply, and the output end outputs a 5V power supply. The input end of the 3.3V voltage regulator is connected to the 5V power supply, and the output end outputs a 3.3V power supply.

4. A digital inclinometer as claimed in claim 3, characterized in that: The main controller, the first AD module, the second AD module, the wireless communication module, the 485 module and the LCD display are all powered by a 3.3V power supply; The first sensor, the second sensor, the third sensor and the fourth sensor are all powered by a 5V power supply; The first adjustable gain amplifier, the first active filter, the second adjustable gain amplifier, the second active filter, the third adjustable gain amplifier, the third active filter, the fourth adjustable gain amplifier and the fourth active filter are all powered by a positive 15V power supply and a negative 15V power supply.

5. A digital inclinometer as claimed in claim 3, characterized in that: The first sensor includes a sensor U1, wherein the OUT1 pin of the sensor U1 is a positive output terminal of the first sensor, and the OUT2 pin is a negative output terminal of the first sensor, the filter circuit A includes a resistor R2, a capacitor C5, a capacitor C6 and a capacitor C7, the filter circuit B includes a resistor R1, a capacitor C1, a capacitor C3 and a capacitor C4, and the first adjustable gain amplifier includes an amplifier OP1, a resistor R3, a resistor R4, a transistor Q1, a transistor Q2, a field effect transistor Q3, a field effect transistor Q4, a resistor R3, a bandgap R4, a resistor R18, a resistor R5, a resistor R15, and a resistor R1 6. Resistor R17, resistor R20, resistor R6 and resistor R21, the OUT1 pin of the sensor U1 is connected to the 2nd pin of the transistor Q1 through the resistor R2, the OUT2 pin is connected to the 2nd pin of the transistor Q2 through the resistor R1, one end of the capacitor C5 is connected to the connection node between the resistor R2 and the 2nd pin of the transistor Q1, and the other end is connected to the ground line, capacitors C6 and C7 are filter capacitors of the 2nd pin of the transistor Q1, one end of the capacitor C1 is connected to the connection node between the resistor R1 and the 2nd pin of the transistor Q2, and the other end is connected to the ground line, capacitors C3 and C4 are filter capacitors of the 2nd pin of the transistor Q2; Pin 1 of transistor Q1 is connected to a positive 15V power supply through resistor R3, pin 1 of transistor Q2 is connected to a positive 15V power supply through resistor R4, the positive input terminal of amplifier OP1 is connected to pin 1 of transistor Q2, and the negative input terminal is connected to pin 1 of transistor Q1, pin 3 of transistor Q1 is connected to the D pole of field effect transistor Q3 through resistor R18, the S pole of field effect transistor Q3 is connected to the negative 15V power supply through resistor R17, the G pole is connected to the ground wire through resistor R15, the G pole of field effect transistor Q3 is connected to the negative 15V power supply through resistor R16, pin 3 of transistor Q2 is connected to the D pole of field effect transistor Q4 through resistor R5, the S pole of field effect transistor Q4 is connected to the negative 15V power supply through resistor R20, the G pole is connected to the negative 15V power supply through resistor R21, the G pole of field effect transistor Q4 is also connected to the output terminal of amplifier OP1 through resistor R6, one end of resistor R19 is connected to the D pole of field effect transistor Q3, and the other end is connected to the D pole of field effect transistor Q4; The first active filter comprises an amplifier OP2, a capacitor C8, a resistor R8, a capacitor C9, a resistor R7, a resistor R9 and a resistor R10, wherein the output end of the amplifier OP1 is connected to one end of the resistor R9 through the resistor R7, wherein the pin 2 of the resistor R7 is connected to the resistor R9, the other end of the resistor R9 is connected to the ground line through the resistor R10, the connection node between the resistor R9 and the resistor R10 is connected to an AD input end of the first AD module, the pin 2 of the resistor R7 is connected to the positive electrode of the capacitor C8, the negative electrode of the capacitor C8 is connected to the negative input end of the amplifier OP2, the positive input end of the amplifier OP2 is connected to the ground line, the output end is connected to the positive electrode of the capacitor C9, the negative electrode of the capacitor C9 is connected to the pin 2 of the resistor R7, and the resistor R8 is connected between the negative input end and the output end of the amplifier OP2; The circuit principles of the second inclination measurement unit, the third inclination measurement unit and the fourth inclination measurement unit are the same as the circuit principle of the first inclination measurement unit.

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