Intelligent vacuum meter based on Pirani principle of MEMS technology

Abstract

The utility model discloses an intelligent vacuum meter based on a Pirani principle of an MEMS technology, which relates to the field of vacuum degree detection and comprises a power supply unit, a sensor module unit, a key unit, an LCD display unit and a microcontroller unit. The power supply unit supplies power to the sensor module unit, the key unit, the LCD display unit and the microcontroller unit; the button unit controls on and off through mechanical buttons, the microcontroller reads vacuum information from the sensor unit through IIC communication and displays the vacuum information on the LCD display unit according to a unit selected by the touch button and a specified unit, and the other touch button controls the backlight state of the LCD. According to the intelligent vacuum meter, the vacuum meter with the electronic module is good in vacuum degree detection effect, small in size, fast in response, good in portability and mobility, convenient and easy to use, display content is easy to customize, and due to the fact that the MCU is used, vacuum information is easy to transmit to a system of a client.

Description

TECHNICAL FIELD

[0001] The utility model relates to vacuum degree detection technical field especially, it is intelligent vacuum gauge based on MEMS technology's pirelli principle. BACKGROUND

[0002] The general measurement vacuum degree is to adopt ionization gauge or vacuum transmitter, and the ionization gauge is large in size and high in power consumption, and the vacuum transmitter is generally used in cooperation with PLC, and has dependence on PLC equipment, which limits the use scene. UTILITY MODEL CONTENTS

[0003] The utility model aims at at least one of the technical problems existing in the prior art. To this end, the utility model embodiment provides an intelligent vacuum gauge based on MEMS technology's pirelli principle, which uses a vacuum sensor, MCU control and communication technology, key input and LCD output technology, and displays the vacuum degree information in real time according to the selected mode. Since it is information that can be conveniently read by the naked eye, it is free from dependence on PLC equipment, and since it is a handheld device powered by a battery, it is convenient to carry and move, and the volume can also be relatively small, thus expanding the convenience and use scene.

[0004] The utility model discloses an intelligent vacuum gauge based on MEMS technology's pirelli principle, which comprises a power supply unit, a sensor module unit, a key unit, an LCD display unit and a microcontroller unit.

[0005] The power supply unit comprises an external power supply input VIN end and a power supply VDD end, the power supply VDD end is the power supply unit output, and the power supply unit provides electricity for the sensor module unit, the key unit, the LCD display unit and the microcontroller unit.

[0006] The sensor module unit detects the vacuum degree of the measured environment and communicates with the microcontroller unit to provide vacuum information.

[0007] The key unit comprises mechanical keys and touch keys and is used for turning on and off, unit adjustment and backlight control.

[0008] The LCD display unit is used for displaying vacuum information.

[0009] The microcontroller unit comprises a microcontroller chip and is used for controlling the sensing unit and the peripheral circuit unit.

[0010] The mechanical keys of the key unit control the on-off, the microcontroller reads the vacuum information from the sensor unit through IIC communication, and displays the vacuum information on the LCD display unit according to the selected unit of the touch keys and the specified unit.

[0011] Further, the power supply unit, the power supply circuit includes a first interface device and voltage stabilizing circuit, the first pin of the first interface device one end of the power supply voltage terminal, the second pin of the first interface device ground, the first pin of the first interface unit and the power control chip first pin connected, the first pin of the first interface unit and the VIN terminal, the power control chip enable EN / NC pin, the first end of the first capacitor, the first end of the second capacitor are connected; the second pin of the first interface unit and the other end of the first capacitor, the other end of the second capacitor, the GND pin of the power control chip are connected in parallel to ground; the 5th pin of the power control chip and the power supply VDD terminal, the first end of the third capacitor, the first end of the fourth capacitor are connected in parallel; the second end of the third capacitor, the second end of the fourth capacitor are connected in parallel to ground.

[0012] Further, the power supply unit VIN terminal and the first resistance one end are connected, the first resistance other end and the third resistance one end are connected in series, the third resistance second end is grounded, the first resistance and the third resistance series terminal are connected with the microcontroller 44th pin PA0 / AD0, the voltage of the power supply unit is monitored by the microcontroller.

[0013] Further, the sensor module unit includes a vacuum sensor, a second interface unit; the power supply VDD terminal and the first end of the second resistance, the source of the first field effect transistor are connected in parallel, the second end of the second resistance and the gate of the first field effect transistor, I2C0_VDD_CTRL are connected in parallel; the drain of the first field effect transistor and the first end of the fifth resistance, the first end of the sixth resistance, the first pin of the second interface end are connected in parallel; the second end of the fifth resistance and the I2C0_SCL terminal, the fourth pin of the second interface end are connected; the second end of the sixth resistance and the I2C0_SDA, the third pin of the second interface end are connected; the second interface end is connected with the vacuum sensor.

[0014] Further, the key unit, the power supply VDD terminal and the first end of the ninth resistance, the first end of the seventeenth capacitor, the first end of the twelfth resistance, the first end of the thirteenth resistance, the eighth pin of the key control chip are connected in parallel; the other end of the ninth resistance and BTN1, the first mechanical switch one end are connected; the other end of the first mechanical switch is connected with the ground; the first pin of the key control chip is connected with the first end of the tenth resistance; the other end of the tenth resistance and the first end of the touch switch LCD_TOUCH1, the first end of the fifteenth capacitor are connected in parallel; the second pin of the key control chip is connected with the first end of the eleventh resistance; the other end of the eleventh resistance and the first end of the touch switch LCD_TOUCH2, the first end of the sixteenth capacitor are connected in parallel; the other end of the fifteenth capacitor and the other end of the sixteenth capacitor are connected in parallel to ground; the sixth pin of the key control chip and the other end of the seventeenth capacitor are connected in parallel to ground; the sixth pin of the key control chip and the other end of the thirteenth resistance, the second switch end are connected; the fifth pin of the key control chip and the other end of the twelfth resistance, the third switch end are connected.

[0015] Further, the LCD display unit is a break code type LCD screen, comprising a display screen, touch keys, and a display backlight control circuit.

[0016] Further, the BL_CTRL end of the display backlight control circuit is connected in parallel with the gate of the second field effect transistor and one end of the fourth resistor; the other end of the fourth resistor is connected in parallel with the source of the second field effect transistor and the VDD end of the power supply; the drain of the second field effect transistor is connected with one end of the seventh resistor; the other end of the seventh resistor is connected with the anode of the second backlight light emitting diode, and the cathode of the second backlight light emitting diode is connected with the ground.

[0017] Further, the microcontroller unit microcontroller chip first pin is connected with the LCD display unit control chip LCD_SEG 7; the microcontroller chip second pin is connected with the LCD display unit control chip LCD_SEG 6; the microcontroller chip third pin is connected with the LCD display unit control chip LCD_SEG 5; the microcontroller chip eighth pin is connected with the I2C0_SCL end; the microcontroller chip ninth pin is connected with the I2C0_SDA end; the microcontroller chip tenth to thirteenth pins are connected with the LCD display unit control chip LCD_SEG4 end to LCD_SEG1 in turn; the microcontroller chip fourteenth pin is connected with the fourteenth capacitor one end, and the fourteenth capacitor other end is connected with the microcontroller chip sixteenth pin and grounded in parallel; the microcontroller chip fifteenth pin is connected with the power supply VDD end; the microcontroller chip twenty-third to twenty-sixth pins are connected with the LCD display unit control chip LCD_COM4 to LCD_COM1 respectively; the microcontroller chip twenty-seventh pin is connected with the seventh capacitor and the microcontroller chip twenty-eighth pin in series; the microcontroller chip twenty-ninth to thirty-second pins are connected with the eighth capacitor to the eleventh capacitor respective one end respectively, and the eighth capacitor to the eleventh capacitor respective other end is grounded in parallel; the microcontroller chip thirty-third pin is connected with the I2C0_VDD_CTRL end; the microcontroller chip thirty-fourth pin is connected with the BL_CTRL end; the microcontroller chip thirty-sixth pin is connected with the LCD display unit display control chip LCD_SEG12 end; the microcontroller chip thirty-seventh to thirty-ninth pins are connected with the third to first switch ends respectively; the microcontroller chip forty-first pin is connected with the ICE_DAT; the microcontroller chip forty-second pin is connected with the ICE_CK; the microcontroller chip forty-third pin is connected with the AGND; the microcontroller chip forty-sixth to forty-eighth pins are connected with the display unit display control chip UART1_RXD, UART1_TXD, LCD_SEG16 in turn respectively; the microcontroller chip forty-ninth, fiftieth pins are connected with the display unit display control chip LCD_SEG15, LCD_SEG14 in turn respectively; the microcontroller chip fifty-first, fifty-second and AVDD end are connected in parallel; the microcontroller chip fifty-third pin is connected with the display unit display control chip LCD_SEG13; the microcontroller chip fifty-fifth to fifty-seventh pins are connected with the display unit display control chip LCD_SEG11, LCD_SEG10, LCD_SEG9 in turn respectively; the microcontroller chip sixty-first, sixty-third and ground are connected in parallel; the microcontroller chip sixty-second pin is connected with the power supply VDD end; the microcontroller chip sixty-fourth pin is connected with the display unit display control chip LCD_SEG8 end.

[0018] The technical scheme provided by the embodiment of the utility model discloses corresponding electronic module according to above scheme design, and it is understood from actual test that the detection effect of the electronic module to vacuum degree is very good, and the volume is small, the response is fast, the portability is very good, and it is convenient and easy to use, and the display content is very easy to customize, and because MCU is used, the vacuum information is very easy to transmit to the system of customer. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and / or additional aspects and advantages of the utility model will become apparent and more readily appreciated from the following description of the embodiments, with reference to the following drawings, in which:

[0020] Figure 1 A kind of intelligent vacuum gauge power supply part structural diagram based on MEMS technology's pirelli principle provided for the embodiment of the utility model;

[0021] Figure 2 A kind of intelligent vacuum gauge monitoring battery level circuit structure schematic provided for the embodiment of the utility model based on MEMS technology's pirelli principle;

[0022] Figure 3 A kind of intelligent vacuum gauge sensor module part structure schematic provided for the embodiment of the utility model based on MEMS technology's pirelli principle;

[0023] Figure 4 A kind of intelligent vacuum gauge key part structure schematic provided for the embodiment of the utility model based on MEMS technology's pirelli principle;

[0024] Figure 5 A kind of intelligent vacuum gauge LCD display part structure schematic provided for the embodiment of the utility model based on MEMS technology's pirelli principle;

[0025] Figure 6 A kind of intelligent vacuum gauge backlight control part structure schematic provided for the embodiment of the utility model based on MEMS technology's pirelli principle;

[0026] Figure 7 A kind of intelligent vacuum gauge microcontroller part structure schematic provided for the embodiment of the utility model based on MEMS technology's pirelli principle;

[0027] Figure 8 A kind of intelligent vacuum gauge circuit principle diagram based on MEMS technology's pirelli principle provided for the embodiment of the utility model. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are used merely for the purpose of explanation of the present application, and are not to be construed as limiting the present application.

[0029] With reference to Figures 1 to 8 The present application discloses a kind of intelligent vacuum gauge based on MEMS technology's PIRANI principle, and the electronic module structure can be divided into five parts, which are power supply part, sensor module part, button part, LCD display part and microcontroller part (abbreviation: MCU) respectively.

[0030] The relationship of each part is as follows:

[0031] The power supply part provides power supply function for other parts, and the MCU can also monitor the battery voltage in real time; The sensor module part can obtain vacuum information from the sensor in real time through certain communication by the MCU; The button part has mechanical key and touch key, which realizes the functions of switching on and off, unit adjustment and backlight control; The LCD display part displays the vacuum information in a specified manner; The MCU part detects and controls the coordinated work of each part.

[0032] The overall working principle is that the mechanical key controls the switching on and off, the MCU reads the vacuum degree information from the sensor part through IIC communication, then displays the vacuum information on the LCD according to the selected unit of the touch key, and the other touch key controls the backlight state of the LCD.

[0033] With reference to Figure 1 The specific working process of the power supply part of the present embodiment is as follows:

[0034] Power supply part: with reference to Figure 1 J1 is the interface of the battery box, which connects three batteries, and the corresponding level is VIN. After U1, the battery level is converted into VDD, which is 3.3v level, for use by various parts. In this embodiment, J1 interface can also be connected with a DC power supply, and the DC power supply voltage is 3.3-4.5V. J1 can be selected as a power interface socket.

[0035] In the embodiment, the power supply part includes a power supply control chip U1, which can be selected as TPL730F33-5TR. The connection mode of the power supply control chip U1 is briefly described as follows. The power supply circuit includes a first interface device J1 and a voltage stabilizing circuit. The first pin of the first interface unit J1 is connected to a power supply voltage end, which is connected to the positive pole of a battery box in the embodiment. The second pin of the first interface device is grounded, which is connected to the negative pole of the battery box in the embodiment. The first pin of the first interface unit J1 is connected to the first pin of the power supply control chip U1. The first pin of the first interface unit J1 is connected to the VIN end, the enable EN / NC pin of the power supply control chip U1, the first end of the first capacitor C1 and the first end of the second capacitor C2. The second pin of the first interface unit J1 is connected to the other end of the first capacitor C1, the other end of the second capacitor C2 and the GND pin of the power supply control chip U1. The fifth pin of the power supply control chip U1 is connected to the power supply VDD end, the first end of the third capacitor C3 and the first end of the fourth capacitor C4. The second end of the third capacitor C3 and the second end of the fourth capacitor C4 are grounded.

[0036] In addition, referring to Figure 2 , the circuit for monitoring the battery level is connected to the VIN end, that is, the battery level, to the ADC pin of the MCU after being divided by two resistors. The MCU can monitor the corresponding level through the ADC function.

[0037] In the embodiment, the first end of the power supply unit VIN end is connected to the first end of the first resistor R1. The other end of the first resistor R1 is connected to the first end of the third resistor R3 in series. The second end of the third resistor is grounded. The series connection end of the first resistor and the third resistor is connected to the 44th pin PA0 / AD0 of the microcontroller. The voltage of the power supply unit is monitored by the microcontroller MCU.

[0038] Referring to Figure 3 , the sensor module part: the sensor can adopt a vacuum sensor module. The module needs to be powered by 3.3V. The corresponding vacuum information needs to be obtained through IIC communication. Therefore, the corresponding circuit includes a power supply control part and an IIC communication part. Figure 3 J2 in the IIC communication part is an interface for connecting the sensor module. The other end of the IIC communication part is connected to the IIC communication interface of the MCU.

[0039] In the embodiment, the sensor module unit comprises a vacuum sensor, a second interface unit J2; the power supply VDD end is connected in parallel with the first end of the second resistor R2 and the source S of the first field effect transistor Q1, the second end of the second resistor R2 is connected in parallel with the gate of the first field effect transistor Q1 and the I2C0_VDD_CTRL end; the drain of the first field effect transistor Q1 is connected in parallel with the first end of the fifth resistor R5, the first end of the sixth resistor R6 and the first pin of the second interface end J2; the second end of the fifth resistor R5 is connected with the I2C0_SCL end and the fourth pin of the second interface end J2; the second end of the sixth resistor R6 is connected with the I2C0_SDA and the third pin of the second interface end J2; the second interface end J2 is connected with the vacuum sensor. The vacuum degree of the environment to be measured is detected by the vacuum sensor, and the vacuum information is provided to the display unit by the microcontroller IIC communication.

[0040] Referring to Figure 4 , the display unit is further described, the key part: there is a mechanical key, mainly responsible for turning on and off, referring to Figure 4 BTN1, there are also two touch keys, referring to Figure 4 BTN2 and BTN3, mainly responsible for setting units and controlling backlight. The touch part of the touch key is in the LCD interface part, that is, the other end of LCD_TOUCH1 and LCD_TOUCH2 comes from the LCD interface part. The LCD interface part is embodied later.

[0041] In the embodiment, the power supply VDD end is connected in parallel with the first end of the ninth resistor R9, the first end of the seventeenth capacitor C17, the first end of the twelfth resistor R12, the first end of the thirteenth resistor R13, and the eighth pin of the key control chip U5; the other end of the ninth resistor is connected with BTN1 and the first end of the first mechanical switch; the other end of the first mechanical switch is connected with the ground; the first pin of the key control chip is connected with the first end of the tenth resistor; the other end of the tenth resistor is connected in parallel with the first end of the touch switch LCD_TOUCH1 and the first end of the fifteenth capacitor; the second pin of the key control chip is connected with the first end of the eleventh resistor R11; the other end of the eleventh resistor R11 is connected in parallel with the first end of the touch switch LCD_TOUCH2 and the first end of the sixteenth capacitor C16; the other end of the fifteenth capacitor C15 is connected in parallel with the other end of the sixteenth capacitor C16 and the ground; the sixth pin of the key control chip U5 is connected in parallel with the other end of the seventeenth capacitor C17 and the ground; the sixth pin of the key control chip U5 is connected with the other end of the thirteenth resistor R13 and the second switch end BTN2; the fifth pin of the key control chip U5 is connected with the other end of the twelfth resistor and the third switch end BTN3. In the embodiment, the type of the key control chip can be selected as BS813C.

[0042] Referring to Figure 5The display part circuit diagram, the embodiment further illustrates the display part, the LCD display part: the display screen is a broken code type LCD screen, not only has display, but also has touch button, the circuit part is as shown in Figure 5 . The display part includes LCD screen and display control chip U3, and U3 is connected with the microcontroller chip.

[0043] Referring to Figure 6 , in order to obtain better display effect, the display part further includes the backlight control part circuit.

[0044] The display backlight control circuit BL_CTRL end is connected with the second field effect tube Q2 gate and the fourth resistance R4 one end in parallel; the fourth resistance R4 other end is connected with the second field effect tube Q2 source and the power supply VDD end in parallel; the second field effect tube Q2 drain is connected with the seventh resistance one end; the seventh resistance R7 other end is connected with the second backlight emitting diode D2 positive pole, and the second backlight emitting diode D2 negative pole is connected with the ground.

[0045] Referring to Figure 7 , the MCU part: this part is to detect and control the coordinated work of other parts. The circuit diagram is as follows:

[0046] The first pin of the microcontroller unit microcontroller chip U4 is connected with the LCD display unit control chip LCD_SEG 7; the second pin of the microcontroller chip is connected with the LCD display unit control chip LCD_SEG 6; the third pin of the microcontroller chip is connected with the LCD display unit control chip LCD_SEG 5; the eighth pin of the microcontroller chip is connected with the I2C0_SCL end; the ninth pin of the microcontroller chip is connected with the I2C0_SDA end; the tenth to thirteenth pins of the microcontroller chip are connected with the LCD display unit control chip LCD_SEG4 end to LCD_SEG1 in turn; the fourteenth pin of the microcontroller chip is connected with one end of the fourteenth capacitor, and the other end of the fourteenth capacitor is connected with the sixteenth pin of the microcontroller chip in parallel with the ground; the fifteenth pin of the microcontroller chip is connected with the power supply VDD end; the twenty-third to twenty-sixth pins of the microcontroller chip are connected with the LCD display unit control chip LCD_COM4 to LCD_COM1 respectively; the twenty-seventh pin of the microcontroller chip is connected with the seventh capacitor and the twenty-eighth pin of the microcontroller chip in series; the twenty-ninth to thirty-second pins of the microcontroller chip are connected with one end of the eighth to eleventh capacitors respectively, and the other end of the eighth to eleventh capacitors is connected with the ground in parallel; the thirty-third pin of the microcontroller chip is connected with the I2C0_VDD_CTRL end; the thirty-fourth pin of the microcontroller chip is connected with the BL_CTRL end; the thirty-sixth pin of the microcontroller chip is connected with the LCD display unit display control chip LCD_SEG12 end; the thirty-seventh to thirty-ninth pins of the microcontroller chip are connected with the third to first switch ends respectively; the forty-first pin of the microcontroller chip is connected with ICE_DAT; the forty-second pin of the microcontroller chip is connected with ICE_CK; the forty-third pin of the microcontroller chip is connected with AGND; the forty-sixth to forty-eighth pins of the microcontroller chip are connected with the display unit display control chip UART1_RXD, UART1_TXD, LCD_SEG16 respectively; the forty-ninth and fiftieth pins of the microcontroller chip are connected with the display unit display control chip LCD_SEG15, LCD_SEG14 respectively; the fifty-first and fifty-second pins of the microcontroller chip are connected with the AVDD end in parallel; the fifty-third pin of the microcontroller chip is connected with the display unit display control chip LCD_SEG13; the fifty-fifth to fifty-seventh pins of the microcontroller chip are connected with the display unit display control chip LCD_SEG11, LCD_SEG10, LCD_SEG9; the sixty-first and sixty-third pins of the microcontroller chip are connected with the ground in parallel; the sixty-second pin of the microcontroller chip is connected with the power supply VDD end; the sixty-fourth pin of the microcontroller chip is connected with the display unit display control chip LCD_SEG8 end.

[0047] The intelligent vacuum gauge based on the Pirani principle of the MEMS technology has the general working principle that the mechanical key control is used to control the start and stop of the vacuum gauge, the MCU reads the vacuum information from the sensor part through IIC communication, then the vacuum information is displayed on the LCD according to the specified unit according to the unit selected by the touch key, and the backlight state of the LCD is controlled by another touch key.

[0048] According to the above scheme design, the corresponding electronic vacuum gauge is designed, and it is understood through actual test that the detection effect of the electronic vacuum gauge on the vacuum degree is very good, the volume is small, the response is fast, the portability and mobility are very good, the electronic vacuum gauge is convenient and easy to use, the display content is very easy to customize, and the vacuum information can be easily transmitted to the system of the customer due to the use of the MCU.

[0049] The above describes the embodiments of the utility model in detail in combination with the drawings, but the utility model is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge range of ordinary skilled in the art without departing from the purpose of the utility model.

[0050] The device embodiments described above are only schematic, and the units described as separate components can or can not be physically separate, that is, can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0051] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the utility model. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0052] Although the embodiments of the utility model have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the utility model, and the scope of the utility model is defined by the claims and their equivalents.

Claims

1. A smart vacuum gauge based on the Pirani principle of MEMS technology, characterized in that, The power supply unit, the sensor module unit, the key unit, the LCD display unit, the microcontroller unit; The power supply unit includes an external power input VIN end and a power supply VDD end, the power supply VDD end is the output of the power supply unit, and the power supply unit provides power for the sensor module unit, the key unit, the LCD display unit and the microcontroller unit; The sensor module unit detects the vacuum degree of the measured environment and communicates with the microcontroller unit to provide vacuum information; The key unit includes mechanical keys and touch keys, which are used for turning on / off, adjusting display units and controlling backlight; The LCD display unit is used for displaying vacuum information; The microcontroller unit includes a microcontroller chip, which is used for controlling the sensing unit and the peripheral circuit unit; The mechanical key of the key unit controls the on / off, the microcontroller reads vacuum information from the sensor unit through IIC communication, and displays the vacuum information on the LCD display unit according to the selected unit of the touch key.

2. The intelligent Pirani principle vacuum gauge based on MEMS technology according to claim 1, wherein the power supply unit comprises a first interface device and a voltage stabilizing circuit, one end of a first pin of the first interface device is connected to a power supply voltage end, a second pin of the first interface device is grounded, the first pin of the first interface device is connected to a first pin of a power supply control chip, the first pin of the first interface device is connected in parallel with the VIN end, an enable EN / NC pin of the power supply control chip, a first end of a first capacitor and a first end of a second capacitor; the second pin of the first interface device is connected in parallel with the other end of the first capacitor, the other end of the second capacitor and a GND pin of the power supply control chip; a fifth pin of the power supply control chip is connected in parallel with the power supply VDD end, a first end of a third capacitor and a first end of a fourth capacitor; a second end of the third capacitor and a second end of the fourth capacitor are connected in parallel to ground; the VIN end of the power supply unit is connected to one end of a first resistor, the other end of the first resistor is connected in series with one end of a third resistor, the second end of the third resistor is grounded, and the series connection end of the first resistor and the third resistor is connected to a 44th pin PA0 / AD0 of the microcontroller chip, and the voltage of the power supply unit is monitored by the microcontroller unit.

3. The intelligent Pirani principle vacuum gauge based on MEMS technology according to claim 1, wherein the sensor module unit comprises a vacuum sensor and a second interface unit; the power supply VDD end is connected in parallel with a first end of a second resistor, a source electrode of a first field effect transistor and I2C0_VDD_CTRL; a drain electrode of the first field effect transistor is connected in parallel with one end of a fifth resistor, one end of a sixth resistor and a first pin of a second interface end; a second end of the fifth resistor is connected to I2C0_SCL end and a fourth pin of the second interface end; a second end of the sixth resistor is connected to I2C0_SDA and a third pin of the second interface end; and the second interface end is connected to the vacuum sensor.

4. The Pirani principle based smart vacuum gauge with MEMS technology according to claim 1, wherein the key unit, the power supply VDD end, one end of the ninth resistor, one end of the seventeenth capacitor, one end of the twelfth resistor, one end of the thirteenth resistor, the eighth pin of the key control chip are connected in parallel; the other end of the ninth resistor is connected with BTN1 and one end of the first mechanical switch; the other end of the first mechanical switch is connected with the ground; the first pin of the key control chip is connected with one end of the tenth resistor; the other end of the tenth resistor is connected with one end of the touch switch LCD_TOUCH1 and one end of the fifteenth capacitor in parallel; the second pin of the key control chip is connected with one end of the eleventh resistor; the other end of the eleventh resistor is connected with one end of the touch switch LCD_TOUCH2 and one end of the sixteenth capacitor in parallel; the other end of the fifteenth capacitor and the other end of the sixteenth capacitor are connected with the ground in parallel; the sixth pin of the key control chip is connected with the other end of the seventeenth capacitor in parallel with the ground; the sixth pin of the key control chip is connected with the other end of the thirteenth resistor and the second switch; the fifth pin of the key control chip is connected with the other end of the twelfth resistor and the third switch.

5. The Pirani principle based smart vacuum gauge with MEMS technology according to claim 1, wherein the key unit further comprises a touch key for controlling the backlight state of the LCD.

6. The Pirani principle based smart vacuum gauge with MEMS technology according to claim 1, wherein the LCD display unit is a broken code type LCD screen, comprising a display screen, a touch key and a display backlight control circuit.

7. The Pirani principle based smart vacuum gauge with MEMS technology according to claim 6, wherein the display backlight control circuit BL_CTRL end, the gate of the second field effect tube, one end of the fourth resistor are connected in parallel; the other end of the fourth resistor is connected with the source of the second field effect tube and the power supply VDD end in parallel; the drain of the second field effect tube is connected with one end of the seventh resistor; the other end of the seventh resistor is connected with the positive electrode of the second backlight light emitting diode, and the negative electrode of the second backlight light emitting diode is connected with the ground.

8. The intelligent Pirani principle vacuum gauge based on MEMS technology according to claim 1, wherein the first pin of the microcontroller unit microcontroller chip is connected with the LCD display unit control chip LCD_SEG 7; the second pin of the microcontroller chip is connected with the LCD display unit control chip LCD_SEG 6; the third pin of the microcontroller chip is connected with the LCD display unit control chip LCD_SEG 5; the eighth pin of the microcontroller chip is connected with the I2C0_SCL end; the ninth pin of the microcontroller chip is connected with the I2C0_SDA end; the tenth to thirteenth pins of the microcontroller chip are connected with the LCD display unit control chip LCD_SEG4 end to LCD_SEG1 in turn; the fourteenth pin of the microcontroller chip is connected with one end of the fourteenth capacitor, and the other end of the fourteenth capacitor is connected with the sixteenth pin of the microcontroller chip in parallel with the ground; the fifteenth pin of the microcontroller chip is connected with the power supply VDD end; the twenty-third to twenty-sixth pins of the microcontroller chip are connected with the LCD display unit control chip LCD_COM4 to LCD_COM1 respectively; the twenty-seventh pin of the microcontroller chip is connected with the seventh capacitor and the twenty-eighth pin of the microcontroller chip in series; the twenty-ninth to thirty-second pins of the microcontroller chip are connected with one end of the eighth to eleventh capacitors respectively, and the other end of the eighth to eleventh capacitors is connected with the ground in parallel; the thirty-third pin of the microcontroller chip is connected with the I2C0_VDD_CTRL end; the thirty-fourth pin of the microcontroller chip is connected with the BL_CTRL end; the thirty-sixth pin of the microcontroller chip is connected with the LCD display unit display control chip LCD_SEG12 end; the thirty-seventh to thirty-ninth pins of the microcontroller chip are connected with the third to first switch ends respectively; the forty-first pin of the microcontroller chip is connected with the ICE_DAT; the forty-second pin of the microcontroller chip is connected with the ICE_CK; the forty-third pin of the microcontroller chip is connected with the AGND; the forty-sixth to forty-eighth pins of the microcontroller chip are connected with the display unit display control chip UART1_RXD, UART1_TXD, LCD_SEG16 in turn respectively; the forty-ninth and fiftieth pins of the microcontroller chip are connected with the display unit display control chip LCD_SEG15 and LCD_SEG14 in turn respectively; the fifty-first and fifty-second pins of the microcontroller chip are connected with the AVDD end in parallel; the fifty-third pin of the microcontroller chip is connected with the display unit display control chip LCD_SEG13; the fifty-fifth to fifty-seventh pins of the microcontroller chip are connected with the display unit display control chip LCD_SEG11, LCD_SEG10, LCD_SEG9 in turn; the sixty-first and sixty-third pins of the microcontroller chip are connected with the ground in parallel; the sixty-second pin of the microcontroller chip is connected with the power supply VDD end; and the sixty-fourth pin of the microcontroller chip is connected with the display unit display control chip LCD_SEG8 end.

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