Air quality detection equipment

Abstract

The utility model relates to the technical field of air detection equipment, and provides air quality detection equipment which comprises a packaging shell, and a control circuit board is arranged in the packaging shell; the control circuit board is provided with a plurality of sensors used for detecting air quality in a classroom, the control circuit board comprises a power supply circuit, a 4G communication module circuit, a sensor acquisition circuit, a Bluetooth interface circuit, an expansion single-chip microcomputer control circuit and a main single-chip microcomputer control circuit, and the power supply circuit supplies power to the control circuit board; the 4G communication module circuit, the sensor acquisition circuit and the extended single-chip microcomputer control circuit are respectively connected with the main single-chip microcomputer control circuit, thereby realizing acquisition of classroom air quality and providing a data basis for effective monitoring of the classroom air quality.

Description

Technical Field

[0001] This utility model belongs to the technical field of air detection equipment, and in particular relates to an air quality detection device. Background Technology

[0002] The quality of classroom teaching is increasingly linked to the classroom environment. With classrooms being densely populated, air quality directly affects the health of teachers and students. For example, high concentrations of exhaled carbon dioxide can cause drowsiness and difficulty concentrating, thus impacting students' listening and learning quality. In winter, poor ventilation can easily lead to carbon dioxide buildup. Indoor temperature and humidity also significantly affect the comfort of both teachers and students; excessively high or low temperatures can negatively impact work and learning efficiency. High humidity can create a stuffy, sticky feeling and promote the growth of bacteria and mold; low humidity can cause dry skin, itchy throats, and other problems. Light intensity and quality play a crucial role in protecting students' eyesight and improving learning outcomes. According to national standards, the average illuminance on classroom desktops should not be less than 300 lux. Appropriate lighting allows students to see books and blackboard content more clearly, reducing eye strain. In newly renovated classrooms or classrooms with new furniture, these harmful gases may exceed safe levels, posing a serious threat to the health of teachers and students.

[0003] In summary, considering the current air quality monitoring environment in classrooms, existing monitoring equipment has the following shortcomings:

[0004] (1) Sensor detection accuracy and sensor detection stability are crucial, but the various sensors currently configured in the classroom are affected by transmission distance and signal interference during data transmission.

[0005] (2) When selecting a power supply for the classroom, the power battery cannot work for a long time and requires frequent maintenance. Although an external power supply can solve the problem of battery life, it has the problems of wiring difficulties and safety. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, this utility model provides an air quality detection device, which aims to solve the problems of interference in sensor data transmission and inconvenient power supply configuration and wiring of existing air quality detection devices configured in classrooms.

[0007] The technical solution provided by this utility model is: an air quality detection device, the air quality detection device including a packaged housing, and a control circuit board disposed inside the packaged housing;

[0008] The control circuit board is equipped with several sensors for detecting the air quality in the classroom. The control circuit board includes a power supply circuit, a 4G communication module circuit, a sensor acquisition circuit, a Bluetooth interface circuit, an extended microcontroller control circuit, and a main microcontroller control circuit. The power supply circuit supplies power to the control circuit board. The 4G communication module circuit, the sensor acquisition circuit, and the extended microcontroller control circuit are respectively connected to the main microcontroller control circuit.

[0009] The sensor acquisition circuit includes a temperature and humidity sensor circuit, a light sensor interface circuit, a spectrum sensor interface circuit, a formaldehyde sensor interface circuit, a PM2.5 sensor circuit, an atmospheric pressure sensor circuit, and a carbon dioxide sensor interface circuit.

[0010] As an improved solution, the power supply circuit includes a step-down rectifier U5. A line from pin 5 of the step-down rectifier U5 is connected to pin 1 of connector VINI. A first circuit node is provided on the line between the pin of the step-down rectifier U5 and pin 1 of connector VINI. A line from the first circuit node is connected in series with a resistor R43 and then connected to pin 4 of the step-down rectifier U5. A line from pin 6 of the step-down rectifier U5 is connected in series with an inductor L2 and then serves as the VDD5V voltage terminal. The inductor L2 and the line from the step-down rectifier U5... A second circuit node is provided on the line between pins 6 and 6. The line leading out of the second circuit node is connected to pin 3 of the buck rectifier U5 after being connected in series with resistor R41. A third circuit node is provided on the line between pin 3 of the buck rectifier U5 and resistor R41. The line leading out of the third circuit node is connected to the VDD5V voltage terminal after being connected in series with resistor R42 and capacitor C45. The line leading out of the VDD5V voltage terminal is connected to pin 1 of voltage regulator chip U6. The line leading out of pin 3 of voltage regulator chip U6 is set as VDD33V voltage terminal.

[0011] As an improved solution, the main microcontroller control circuit includes a microcontroller chip U1, the extended microcontroller control circuit includes an extended microcontroller chip U111, pins 5 and 6 of the microcontroller chip U1 are connected to pins 6 and 5 of the extended microcontroller chip U111, the 4G communication module circuit includes a 4G communication chip U10, the line from pin 6 of the 4G communication chip U10 is connected to pin 48 of the microcontroller chip U1, and the lines from pins 2 and 3 of the 4G communication chip U10 are connected to pins 46 and 45 of the microcontroller chip U1, respectively.

[0012] As an improved solution, the control circuit board is also provided with an indicator light circuit and a buzzer circuit, which are respectively connected to the main microcontroller control circuit.

[0013] As an improved solution, the Bluetooth interface circuit includes a Bluetooth interface J2. The line leading out from pin 3 of the Bluetooth interface J2 is connected to the VDD33V voltage terminal. The line leading out from pin 6 of the Bluetooth interface J2 is connected to pin 47 of the microcontroller chip U1. The lines leading out from pins 13 and 14 of the Bluetooth interface J2 are correspondingly connected to pins 46 and 465 of the microcontroller chip U1.

[0014] As an improved solution, the atmospheric pressure sensor circuit includes a pressure sensor chip U4. The lines leading out from pins 3 and 4 of the pressure sensor chip U4 are respectively connected to pins 39 and 40 of the microcontroller chip U1. At the same time, the lines leading out from pins 2, 3, and 4 of the pressure sensor chip U4 are connected in series with resistors R6, R32, and R31 and then connected to the VDD33V voltage terminal.

[0015] In this invention, the air quality detection device includes a housing, within which a control circuit board is installed. The control circuit board has several sensors for detecting air quality in the classroom. The control circuit board includes a power supply circuit, a 4G communication module circuit, a sensor acquisition circuit, an extended microcontroller control circuit, and a main microcontroller control circuit. The power supply circuit supplies power to the control circuit board. The 4G communication module circuit, sensor acquisition circuit, and extended microcontroller control circuit are respectively connected to the main microcontroller control circuit, thereby enabling the collection of classroom air quality data and providing a data foundation for effective monitoring of classroom air quality. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 This is a structural block diagram of the air quality detection equipment provided by this utility model;

[0018] Figure 2 This is a circuit diagram of the power supply circuit provided by this utility model;

[0019] Figure 3 This is a circuit diagram of the main microcontroller control circuit provided by this utility model;

[0020] Figure 4 This is a circuit diagram of the extended microcontroller control circuit provided by this utility model;

[0021] Figure 5 This is a circuit diagram of the 4G communication module circuit provided by this utility model;

[0022] Figure 6 This is a circuit diagram of the sensor acquisition circuit provided by this utility model;

[0023] Figure 7 This is a circuit diagram of the temperature and humidity sensor circuit provided by this utility model;

[0024] Figure 8 This is a circuit diagram of the light sensor interface circuit provided by this utility model;

[0025] Figure 9 This is a circuit diagram of the spectral sensor interface circuit provided by this utility model;

[0026] Figure 10 This is a circuit diagram of the formaldehyde sensor interface circuit provided by this utility model;

[0027] Figure 11 This is a circuit diagram of the PM2.5 sensor circuit provided by this utility model;

[0028] Figure 12 This is a circuit diagram of the carbon dioxide sensor interface circuit provided by this utility model;

[0029] Figure 13 This is a circuit diagram of the indicator light circuit provided by this utility model;

[0030] Figure 14 This is a circuit diagram of the buzzer circuit provided by this utility model;

[0031] Figure 15 This is a circuit diagram of the Bluetooth interface circuit provided by this utility model;

[0032] Figure 16 This is a circuit diagram of the atmospheric pressure sensor circuit provided by this utility model. Detailed Implementation

[0033] The embodiments of the present utility model will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present utility model and should not be construed as limiting its scope of protection.

[0034] Figure 1 This is a structural block diagram of the air quality detection device provided by this utility model. For ease of explanation, only the parts related to this utility model are shown in the figure.

[0035] The air quality detection equipment includes a housing, inside which a control circuit board is housed;

[0036] The control circuit board is equipped with several sensors for detecting the air quality in the classroom. The control circuit board includes a power supply circuit 11, a 4G communication module circuit 12, a sensor acquisition circuit 13, a Bluetooth interface circuit 24, an extended microcontroller control circuit 14, and a main microcontroller control circuit 15. The power supply circuit 11 supplies power to the control circuit board. The 4G communication module circuit 12, the sensor acquisition circuit 13, the Bluetooth interface circuit 24, and the extended microcontroller control circuit 14 are respectively connected to the main microcontroller control circuit 15.

[0037] In this embodiment, a microcontroller development board with powerful processing capabilities and 4G module expansion support is selected as the control circuit board. This board is responsible for coordinating data acquisition and processing from various sensors, as well as communication with external networks. The development board is ensured to have sufficient GPIO pins to connect various sensors, and its operating voltage is compatible with subsequent circuits, typically adaptable to logic levels of 3.3V - 5V.

[0038] like Figure 2 As shown, the power supply circuit 11 includes a step-down rectifier U5. A line from pin 5 of the step-down rectifier U5 is connected to pin 1 of connector VINI. A first circuit node is provided on the line between the pin of the step-down rectifier U5 and pin 1 of connector VINI. A line from the first circuit node is connected in series with resistor R43 and then connected to pin 4 of the step-down rectifier U5. A line from pin 6 of the step-down rectifier U5 is connected in series with inductor L2 and then serves as the VDD 5V voltage terminal. A second circuit node is provided on the line between inductor L2 and pin 6 of the step-down rectifier U5. A line from the second circuit node is connected to... The circuit is connected to pin 3 of the step-down rectifier U5 after being connected in series with resistor R41. A third circuit node is provided on the circuit between pin 3 of the step-down rectifier U5 and resistor R41. The circuit leading out of the third circuit node is connected to the VDD5V voltage terminal after being connected in series with resistor R42 and capacitor C45. The circuit leading out of the VDD5V voltage terminal is connected to pin 1 of the voltage regulator chip U6. The circuit leading out of pin 3 of the voltage regulator chip U6 is set as the VDD33V voltage terminal. The model of step-down rectifier U5 is JW5026, and the model of voltage regulator chip U6 is LM1117-33.

[0039] The power supply circuit 11 is a 220V to 12DC voltage regulator circuit, which can use linear voltage regulator chips such as LM7805 and AMS1117 or high-efficiency DC-DC buck chips. This ensures that the input 12V DC power is stably converted to the operating voltage required by the sensor and main control board, providing reliable power for the entire device. A filter capacitor is also included to reduce power supply ripple interference.

[0040] Combination Figure 3 and Figure 4As shown, the main microcontroller control circuit includes a microcontroller chip U1, and the extended microcontroller control circuit 14 includes an extended microcontroller chip U111. Pins 5 and 6 of the microcontroller chip U1 are connected to pins 6 and 5 of the extended microcontroller chip U111, respectively. Figure 5 As shown, the 4G communication module circuit 12 includes a 4G communication chip U10. The line leading from pin 6 of the 4G communication chip U10 is connected to pin 48 of the microcontroller chip U1. The lines leading from pins 2 and 3 of the 4G communication chip U10 are connected to pins 46 and 45 of the microcontroller chip U1, respectively. The 4G communication chip U10 is selected to support mainstream 4G frequency bands and has a standard TTL interface, such as Quectel EC20. It is connected to the control circuit board via a UART serial port (TTL level) to achieve high-speed connection between the device and the Internet, enabling real-time uploading of monitoring data to a cloud server or remote monitoring terminal. Both the aforementioned microcontroller chip U1 and the extended microcontroller chip U111 can be of the STC32G12K64 model.

[0041] Combination Figure 6 As shown, the sensor acquisition circuit 13 includes, but is not limited to, a temperature and humidity sensor circuit 16, a light sensor interface circuit 17, a spectrum sensor interface circuit 18, a formaldehyde sensor interface circuit 19, a PM2.5 sensor circuit 20, an atmospheric pressure sensor circuit 25, and a carbon dioxide sensor interface circuit 21. The temperature and humidity sensor circuit 16, the light sensor interface circuit 17, the spectrum sensor interface circuit 18, the formaldehyde sensor interface circuit 19, the PM2.5 sensor circuit 20, the atmospheric pressure sensor circuit 25, and the carbon dioxide sensor interface circuit 21 are respectively connected to the microcontroller chip U1.

[0042] like Figure 7 As shown, the temperature and humidity sensor circuit 16 includes a temperature and humidity sensor U3. The line from pin 1 of the temperature and humidity sensor U3 is connected to pin 35 of the microcontroller chip U1, and is connected to the VDD33V voltage terminal after being connected in series with resistor R2. The line from pin 6 of the temperature and humidity sensor U3 is connected to pin 36 of the microcontroller chip U1, and is connected to the VDD33V voltage terminal after being connected in series with resistor R1. The line from pin 5 of the temperature and humidity sensor U3 is connected to the VDD33V voltage terminal. A fourth circuit node is provided on the line between pin 5 of the temperature and humidity sensor U3 and the VDD33V voltage terminal. The line from the fourth circuit node is connected to ground after being connected in series with capacitor C41.

[0043] Among them, a high-precision temperature and humidity sensor, model SHT20, is selected. This sensor integrates advanced sensing elements and can measure the ambient temperature and humidity with high accuracy. The output digital signal can be directly connected to the GPIO pin of the control circuit board and adopts the TTL communication protocol for convenient data reading and processing.

[0044] like Figure 8 As shown, the light sensor interface circuit 17 includes a light sensor slot GZ. The line leading out from pin 1 of the light sensor slot GZ is connected to the VDD33V voltage terminal. The lines leading out from pins 2 and 3 of the light sensor slot GZ are respectively connected to pins 10 and 9 of the microcontroller chip U1. A fifth circuit node is provided on the line between pin 2 of the light sensor slot GZ and pin 10 of the microcontroller chip U1. A sixth circuit node is provided on the line between pin 3 of the light sensor slot GZ and pin 9 of the microcontroller chip U1. The line leading out from the fifth circuit node is connected to the VDD33V voltage terminal after being connected in series with resistor R29. The line leading out from the sixth circuit node is connected to the VDD33V voltage terminal after being connected in series with resistor R30.

[0045] The system employs a silicon photovoltaic cell light sensor, which operates based on the photoelectric effect. Different light intensities result in varying photocurrents generated by the silicon photovoltaic cells. The measurement range is typically 0-20000 lux, with an accuracy of ±5%. It can accurately measure the lighting conditions in different locations and at different times within a classroom, providing a reliable basis for classroom lighting design and adjustment. The light sensor is compact, consumes little power, measures ambient light intensity, and transmits data digitally to the control circuit board via the TTL protocol, providing a basis for judging the classroom's lighting conditions.

[0046] like Figure 9 As shown, the spectral sensor interface circuit 18 includes a spectral sensor interface SCOM3. The line leading out from pin 1 of the spectral sensor interface SCOM3 is connected to the VDD5V voltage terminal. The lines leading out from pin 2 and pin 3 of the spectral sensor interface SCOM3 are respectively connected to pin 43 and pin 44 of the microcontroller chip U1.

[0047] The spectral sensor is selected to cover the visible light band (e.g., 350-1000nm) and has a certain spectral resolution. It can analyze the spectral composition of light, determine the spectral quality of classroom lights, and output data to the control circuit board via TTL, helping to create a high-quality lighting environment.

[0048] like Figure 10As shown, the formaldehyde sensor interface circuit 19 includes a formaldehyde sensor interface S2COM4. The lines leading from pins 2 and 3 of the formaldehyde sensor interface S2COM4 are respectively connected to pins 45 and 46 of the extended microcontroller chip U111. An electrochemical formaldehyde sensor is used, exhibiting high sensitivity to formaldehyde. The measurement range is 0-5 ppm, with an accuracy ≤0.01 ppm, enabling rapid detection of formaldehyde released from decoration materials, furniture, etc., ensuring indoor air quality safety.

[0049] like Figure 11 As shown, the PM2.5 sensor circuit 20 includes a PM2.5 sensor Sx2. Pins 1 and 2 of the PM2.5 sensor Sx2 are connected to the VDD5V voltage terminal, respectively. The lines led out from pins 7 and 9 of the PM2.5 sensor Sx2 are connected to pins 44 and 43 of the extended microcontroller chip U111, respectively.

[0050] Among them, the PM2.5 and PM10 sensors are sensors that use the principle of laser scattering. They can accurately measure the concentration of fine particulate matter in the air, output digital signals and communicate with the control circuit board in TTL mode, so as to remind teachers and students to pay attention to air quality in a timely manner.

[0051] like Figure 12 As shown, the carbon dioxide sensor interface circuit 21 includes a carbon dioxide sensor connector COCO2_2. The pins 3 and 2 of the carbon dioxide sensor connector COCO2_2 are connected to pins 19 and 20 of the extended microcontroller chip U111.

[0052] The carbon dioxide sensor utilizes a non-dispersive infrared absorption (NDIR) sensor, characterized by high accuracy and stability. Its measurement range is typically 0-5000 ppm, with an accuracy of ±(30 ppm + 3% of the reading). It effectively reflects changes in CO2 concentration in the classroom caused by respiration, promptly alerting the need for ventilation when the concentration is too high. The carbon dioxide sensor uses a chemical reaction principle to detect changes in carbon dioxide concentration (0-5000 ppm), outputting an analog signal which is converted by an ADC and then connected to the control circuit board. Adhering to TTL communication standards, it provides real-time feedback on the carbon dioxide content in the classroom, which is of great significance for assessing ventilation conditions.

[0053] Combination Figure 1 and Figure 13As shown, the control circuit board is also equipped with an indicator light circuit 22. The indicator light circuit includes resistor R20 and resistor R21. One end of resistor R20 is connected to pin 21 of the microcontroller chip U1, and the other end is connected in series with LED LD1 and then grounded. One end of resistor R21 is connected to pin 22 of the microcontroller chip U1, and the other end is connected in series with LED LD2 and then grounded.

[0054] Combination Figure 1 and Figure 14 As shown, the control circuit board is also equipped with a buzzer circuit 23. The buzzer circuit includes a resistor R13 connected to pin 31 of the microcontroller chip U1. The other end of the resistor R13 is connected to the gate of the transistor Q1. The collector of the transistor Q1 is connected to the speaker. The emitter of the transistor Q1 is grounded.

[0055] Combination Figure 1 and Figure 15 As shown, the control circuit board is also equipped with a Bluetooth interface circuit 24. The Bluetooth interface circuit includes a Bluetooth interface J2. The line led out from pin 3 of the Bluetooth interface J2 is connected to the VDD33V voltage terminal. The line led out from pin 6 of the Bluetooth interface J2 is connected to pin 47 of the microcontroller chip U1. The lines led out from pins 13 and 14 of the Bluetooth interface J2 are connected to pins 46 and 465 of the microcontroller chip U1 respectively.

[0056] like Figure 16 As shown, the atmospheric pressure sensor circuit 26 includes a pressure sensor chip U4. The lines leading out from pins 3 and 4 of the pressure sensor chip U4 are respectively connected to pins 39 and 40 of the microcontroller chip U1. At the same time, the lines leading out from pins 2, 3, and 4 of the pressure sensor chip U4 are connected in series with resistors R6, R32, and R31 and then connected to the VDD33V voltage terminal.

[0057] The air quality detection device of this invention has the following specific features:

[0058] (1) Software programming and debugging

[0059] Development environment setup: Install an integrated development environment (IDE) suitable for the control circuit board on the computer, such as Keil or IAR, and configure the corresponding compiler and debugging tools to ensure that the program can be successfully written, compiled and downloaded to the main control board;

[0060] (2) Sensor driver programming

[0061] For each type of sensor, driver code is written according to its datasheet. Taking the temperature and humidity sensor as an example, the temperature and humidity data output by the sensor is read by controlling the GPIO pins of the control board according to a specific timing sequence and converted into actual physical quantity values. The same applies to other sensors to ensure accurate and stable data acquisition.

[0062] (3) 4G communication program development

[0063] By utilizing the AT command set or SDK provided by the 4G module, a 4G communication program can be developed on the control circuit board to enable automatic network connection and registration after the device is powered on. It can also package the collected environmental data in a predetermined format (such as JSON format) and upload it to a designated server address via the 4G network. At the same time, it can receive remote configuration commands from the server to achieve remote control of the device.

[0064] (4) Data processing and alarm logic

[0065] Data processing algorithms are set in the control circuit board program to perform real-time analysis of various environmental data collected. For example, this includes calculating the average carbon dioxide concentration over a period of time and determining the trend of PM2.5 concentration changes. Alarm thresholds for each parameter are set according to educational departments or relevant standards. When the detected value exceeds the threshold, the alarm module is immediately activated, and an alarm message is pushed to the server.

[0066] (5) Implementation of timer switch function

[0067] The program integrates timed switch logic, which reads the real-time clock (RTC) module or system time to determine if the current time falls within a preset shutdown period. If so, a shutdown command is executed, shutting down the corresponding sensors or putting the entire device into a low-power standby state. Once the shutdown time is reached, the device is automatically woken up and resumes normal monitoring.

[0068] (6) Assembly and packaging

[0069] The selected control circuit board, sensor module, 4G module, power module, and alarm circuit, along with other electronic components, are neatly soldered or connected to the custom printed circuit board (PCB) according to the circuit design layout. Careful wiring is essential to avoid signal interference; power and signal lines should be kept as short as possible to improve circuit stability.

[0070] Install the assembled control circuit board into the selected enclosure. The enclosure size can be designed according to actual needs, generally considering ease of portability, wall mounting, or desktop placement. The enclosure is made of insulating and durable materials, such as ABS plastic. Pre-installed mounting positions are provided for sensor detection windows, power interfaces, 4G antenna interfaces, indicator lights, buttons, and other operating components, ensuring the overall aesthetics and practicality of the equipment.

[0071] In this utility model, the following are the steps for using the air quality detection device (hereinafter referred to as the device):

[0072] (1) Equipment installation

[0073] First, select a suitable installation location based on the actual layout of the classroom and usage needs. If the focus is on monitoring overall air quality, the equipment can be installed in a higher position in the center of the classroom to avoid direct interference from people's activities; if the focus is on the impact of lighting on specific areas, such as near the podium, the light sensor and spectrum sensor can be installed on a nearby wall facing the light source.

[0074] Use wall-mounting accessories (such as expansion bolts, hooks, etc.) or a desktop stand to secure the device in the selected location. Ensure the installation is firm and will not fall and be damaged due to accidental impact. Connect the device to a 12V DC power supply, ensuring the positive and negative terminals are connected correctly to avoid reversing the power supply and damaging the device.

[0075] (2) Device initialization and networking

[0076] Turn on the device power switch and wait for the device to start up. After the control circuit board starts up, it will automatically initialize each sensor module. At this time, observe the status of the indicator lights on the device. Under normal circumstances, the indicator lights corresponding to each sensor will flash briefly, indicating that a self-test is in progress.

[0077] After the device starts up, the 4G communication module will automatically search for nearby 4G base stations and attempt to connect to the network. After a short wait, if the indicator light shows successful 4G connection (e.g., two consecutive beeps), it means the device has successfully connected to the internet and you can proceed to the next step.

[0078] (3) Parameter configuration and threshold setting

[0079] Connect to the device using the computer-based management software (which needs to be installed and an account registered beforehand). The software interface displays real-time environmental monitoring data, such as current temperature, humidity, and carbon dioxide concentration.

[0080] Based on the actual usage scenarios and requirements of the classrooms, alarm thresholds for various environmental parameters can be set in the management software. For example, for classrooms with high population density, the carbon dioxide concentration alarm threshold can be set at around 1500 ppm; for classrooms with higher air quality requirements, the PM2.5 alarm threshold can be set at 35 μg / m³. Additionally, timed switching intervals can be set, such as turning off unnecessary sensors from 10 PM to 6 AM the following morning to save energy.

[0081] (4) Daily use and monitoring

[0082] During the teaching process, the equipment automatically collects various environmental parameters at a set frequency (e.g., once every 5 minutes) and uploads them to the cloud server in real time via 4G network. Teachers, students, or administrators can view the real-time environmental status of the classroom at any time through a mobile app or computer software.

[0083] When the device detects that an environmental parameter exceeds the alarm threshold, the mobile app or computer software will receive a push notification, reminding relevant personnel to take measures to improve the classroom environment, such as opening windows for ventilation to reduce carbon dioxide concentration, or turning on air purifiers to deal with particulate matter pollution.

[0084] (5) Maintenance and upkeep

[0085] Clean the equipment regularly (e.g., once a month), wiping the casing and sensor detection window with a clean, soft cloth to prevent dust accumulation from affecting sensor performance.

[0086] Check that the power connection is secure; tighten it immediately if it is loose. Calibrate the equipment every six months or one year. Contact the equipment manufacturer or a professional calibration agency to calibrate sensors such as those for carbon dioxide, temperature, and humidity using standard gases and temperature / humidity sources to ensure the accuracy of the monitoring data.

[0087] By following the above manufacturing methods and usage steps, this classroom environment monitoring device can effectively provide strong support for classroom environment management and help create a healthy, comfortable, and intelligent teaching environment.

[0088] In this invention, the air quality detection device includes a housing, within which a control circuit board is installed. The control circuit board is equipped with several sensors for detecting air quality in the classroom. The control circuit board includes a power supply circuit 11, a 4G communication module circuit 12, a sensor acquisition circuit 13, an extended microcontroller control circuit 14, and a main microcontroller control circuit. The power supply circuit 11 supplies power to the control circuit board. The 4G communication module circuit 12, the sensor acquisition circuit 13, and the extended microcontroller control circuit 14 are respectively connected to the main microcontroller control circuit, thereby enabling the collection of classroom air quality data and providing a data foundation for effective monitoring of classroom air quality.

[0089] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. An air quality detection device, characterized in that, The air quality detection device includes a housing, and a control circuit board is disposed inside the housing. The control circuit board is equipped with several sensors for detecting the air quality in the classroom. The control circuit board includes a power supply circuit, a 4G communication module circuit, a sensor acquisition circuit, a Bluetooth interface circuit, an extended microcontroller control circuit, and a main microcontroller control circuit. The power supply circuit supplies power to the control circuit board. The 4G communication module circuit, the sensor acquisition circuit, the Bluetooth interface circuit, and the extended microcontroller control circuit are respectively connected to the main microcontroller control circuit. The sensor acquisition circuit includes a temperature and humidity sensor circuit, a light sensor interface circuit, a spectrum sensor interface circuit, a formaldehyde sensor interface circuit, a PM2.5 sensor circuit, an atmospheric pressure sensor circuit, and a carbon dioxide sensor interface circuit.

2. The air quality detection equipment according to claim 1, characterized in that, The power supply circuit includes a step-down rectifier U5. A line from pin 5 of the step-down rectifier U5 is connected to pin 1 of connector VINI. A first circuit node is provided on the line between the pin of the step-down rectifier U5 and pin 1 of connector VINI. A line from the first circuit node is connected in series with a resistor R43 and then connected to pin 4 of the step-down rectifier U5. A line from pin 6 of the step-down rectifier U5 is connected in series with an inductor L2 and then serves as the VDD 5V voltage terminal. The connection between the inductor L2 and pin 6 of the step-down rectifier U5... A second circuit node is provided on the line. The line leading out of the second circuit node is connected to pin 3 of the step-down rectifier U5 after being connected in series with resistor R41. A third circuit node is provided on the line between pin 3 of the step-down rectifier U5 and resistor R41. The line leading out of the third circuit node is connected to the VDD5V voltage terminal after being connected in series with resistor R42 and capacitor C45. The line leading out of the VDD5V voltage terminal is connected to pin 1 of voltage regulator chip U6. The line leading out of pin 3 of voltage regulator chip U6 is set as the VDD33V voltage terminal.

3. The air quality detection equipment according to claim 2, characterized in that, The main microcontroller control circuit includes a microcontroller chip U1, and the extended microcontroller control circuit includes an extended microcontroller chip U111. Pins 5 and 6 of the microcontroller chip U1 are connected to pins 6 and 5 of the extended microcontroller chip U111. The 4G communication module circuit includes a 4G communication chip U10. The line leading out from pin 6 of the 4G communication chip U10 is connected to pin 48 of the microcontroller chip U1, and the lines leading out from pins 2 and 3 of the 4G communication chip U10 are connected to pins 46 and 45 of the microcontroller chip U1, respectively.

4. The air quality detection device according to claim 3, characterized in that, The control circuit board is also equipped with an indicator light circuit and a buzzer circuit, which are respectively connected to the main microcontroller control circuit.

5. The air quality detection device according to claim 3, characterized in that, The Bluetooth interface circuit includes a Bluetooth interface J2. The line leading out from pin 3 of the Bluetooth interface J2 is connected to the VDD33V voltage terminal. The line leading out from pin 6 of the Bluetooth interface J2 is connected to pin 47 of the microcontroller chip U1. The lines leading out from pins 13 and 14 of the Bluetooth interface J2 are connected to pins 46 and 465 of the microcontroller chip U1 respectively.

6. The air quality detection device according to claim 3, characterized in that, The atmospheric pressure sensor circuit includes a pressure sensor chip U4. The lines leading out from pins 3 and 4 of the pressure sensor chip U4 are respectively connected to pins 39 and 40 of the microcontroller chip U1. At the same time, the lines leading out from pins 2, 3, and 4 of the pressure sensor chip U4 are connected in series with resistors R6, R32, and R31 and then connected to the VDD33V voltage terminal.

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