CN105241504A - Distributed indoor environment quality detection system - Google Patents

Abstract

The invention is a distributed indoor environment quality detection system, the system is composed of a master module and a plurality of slave modules, the slave module collects the environmental parameters around the slave module through sensors, uses a single-chip microcomputer to process data, and realizes the environmental parameters Display, data recording, and alarm functions. The slave module receives various instructions sent by the host through wireless transmission, and sends real-time data to the host module. The host module realizes unified management and monitoring of all slave modules through the communication mode of polling extension Real-time monitoring, the host module displays the received extension data through the display module on the panel, and realizes the visual monitoring of the extension data.

Description

A Distributed Indoor Environmental Quality Detection System

technical field

The invention relates to the technical field of indoor environment monitoring, in particular to a distributed indoor environment quality detection system.

Background technique

With the continuous expansion of my country's industrial scale, the current PM2.5 value in major cities remains high, causing serious pollution to the indoor environment. People spend most of their lives indoors. While people are enjoying a more modern living life, health problems caused by indoor environmental quality have increased sharply and cost a lot. Indoor environmental pollutants will directly affect human health. Studies have shown that indoor environmental pollution has become one of the killers of modern human health, and real-time monitoring of indoor environmental quality is very necessary.

In terms of air quality monitoring, foreign countries have done better: the 4000 air quality analyzer produced by the American Interscan Technology Company, the PPM-400 formaldehyde detector produced by the British PPM company; the domestic ones are: Handan Perui Gas Equipment Co., Ltd. The "Perui" series of air health meters developed, the "Jiabaoyu" brand indoor environmental pollution calibration instrument produced by Jiangxi Nanchang Beigu Technology Co., Ltd., etc. Through the comparative analysis of the above instruments, it is found that the main differences between domestic and foreign products focus on the completeness of functions, detection accuracy and user experience. Foreign products have relatively complete functions, high measurement accuracy and relatively user-friendly system interface, while domestic similar The product has obvious advantages in price but single function and poor user experience. All of the above-mentioned instruments can detect harmful gases in the air, but the equipment is expensive, the measurement time is long, and the portability is not good. Some of them need professional testing personnel to operate, and it is difficult to measure continuously.

At present, the indoor air detectors on the market are relatively simple in measurement, and a measuring instrument can usually only detect one indoor air pollution factor. The national standard (GB/T18883-2002) requires that the area of the room is larger than 50m2, and two or more inspection points are required. Hand-held detectors on the market generally have a display center and a sensor module together. In this case, the measurement is easily affected by the measuring instrument's own factors (such as the heating of the instrument), and it is difficult to achieve accurate measurement. In addition, with the development of wireless communication technology, many short- and medium-distance wireless communication modules have begun to be used in smart home control systems. Therefore, it is possible to use short- and medium-distance wireless communication modules to realize wireless communication between the display center of the testing instrument and the sensor module. . Based on the above reasons, a distributed indoor environment monitoring system was developed for multi-point, real-time, comprehensive and accurate monitoring of formaldehyde, benzene and other TVOC, dust particles and other air pollutants in the indoor environment, as well as air quality factors such as temperature and humidity and carbon dioxide. is very meaningful.

Contents of the invention

The purpose of the present invention is to overcome the problems existing in the prior art and provide a distributed indoor environment quality detection system.

In order to achieve the above-mentioned technical purpose and achieve the above-mentioned technical effect, the present invention is realized through the following technical solutions:

A distributed indoor environment quality detection system, the system includes a host module and a slave module distributed indoors, the host module consists of a host single-chip microcomputer, and a host power supply module, a clock module, a reset module, and a display module respectively connected to the host single-chip microcomputer Composed of a host communication module, the slave module consists of a slave single-chip microcomputer, a slave power supply module, a clock module, a reset module, a slave communication module, a temperature and humidity measurement module, a carbon monoxide measurement module, and a carbon dioxide measurement module respectively connected to the slave single-chip microcomputer. Module, formaldehyde measurement module and PM2.5 measurement module, wherein, the master module transmits data and commands to multiple slave modules through wireless communication, and the slave modules collect the surrounding Environmental parameters and transmit the environmental parameters to the host module through wireless communication, and the host module realizes unified management and real-time monitoring of all slave modules through the communication mode of polling extensions.

Further, the host single-chip microcomputer adopts the STC12C5A60S2 chip to receive various measurement data transmitted from the slave single-chip microcomputer, and the slave single-chip microcomputer adopts the STC12C5A60S2 chip to measure various indoor air quality parameters through each sensor module connected thereto, and Send the measured parameters to the host microcontroller.

Further, the master/slave power module adopts AMS1117-3.3 chip and AMS1117-5.0 chip, which generate 3.3V voltage and 5V voltage for power supply respectively.

Further, the reset module is composed of a capacitor and a resistor connected between the master/slave power supply module and the reset terminal of the master/slave microcontroller.

Further, the display module adopts a TFT2.8 touch color screen for displaying the measurement parameters of each slave module.

Further, both the host communication module and the slave communication module use the XL4432-SMT wireless communication module, which is used for wireless data communication between the host microcontroller and the slave microcontroller.

Further, the temperature and humidity measurement module adopts a DHT11 digital temperature and humidity sensor for measuring the temperature and humidity parameter values in the indoor environment.

Further, the carbon monoxide measurement module adopts the ZYMQ-7 carbon monoxide measurement sensor for measuring the carbon monoxide parameter value in the indoor environment, and the carbon dioxide measurement module adopts the MG811 carbon dioxide measurement sensor for measuring the carbon dioxide parameter value in the indoor environment.

Further, the formaldehyde measurement module adopts MS1100 formaldehyde measurement sensor for measuring formaldehyde parameter values in the indoor environment.

Further, the PM2.5 measurement module adopts the GP2Y1010AU0F dust sensor for measuring the PM2.5 parameter value in the indoor environment.

The beneficial effects of the present invention are:

1. The present invention can accurately monitor multiple environmental quality parameters, including formaldehyde concentration, temperature, humidity, dust concentration, CO and _CO2 concentration.

2. In the present invention, the master module and the slave module transmit data and commands through wireless communication, so as to realize data communication and monitoring between multiple slave modules and one master module.

3. In the present invention, a touch screen man-machine interface is used to visually monitor the environmental parameters detected by the slave machine through the touch screen.

4. The slave module of the present invention is arranged in a multi-point distributed manner, which can monitor various environmental parameters, and the monitoring results are more accurate and effective.

Description of drawings

Fig. 1 is the structural representation of host module of the present invention;

Fig. 2 is a schematic structural diagram of a slave module of the present invention;

Fig. 3 is the minimum system circuit diagram of the host microcontroller;

Fig. 4 is the minimum system circuit diagram of the slave microcontroller;

Figure 5 is a +5V voltage conversion circuit;

Figure 6 is a +3.3V voltage conversion part of the circuit;

Figure 7 is a circuit diagram of the display module;

Figure 8 is a circuit diagram of the master/slave communication module;

Fig. 9 is a temperature and humidity measurement circuit diagram;

Figure 10 is a carbon monoxide measurement circuit diagram;

Figure 11 is a carbon dioxide measurement circuit diagram;

Fig. 12 is a formaldehyde measurement circuit diagram;

Figure 13 is a PM2.5 measurement circuit;

Fig. 14 is a flow chart of host module control;

Figure 15 is a flow chart of TFT2.8 touch screen control;

Figure 16 is a flow chart of slave module control;

Figure 17 is a flowchart of temperature and humidity measurement in the slave module;

Fig. 18 is a flow chart of AD conversion in the slave module;

Figure 19 is a master/slave module wireless transmission control flow chart;

Fig. 20 is a flow chart of master/slave module wireless receiving control.

detailed description

The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

As shown in Figure 1 and Figure 2, a distributed indoor environment quality detection system, the system includes a host module and a slave module distributed indoors, the host module consists of a host single-chip microcomputer and a host power supply module connected to the host single-chip microcomputer respectively , a clock module, a reset module, a display module and a host communication module. Measurement module, carbon monoxide measurement module, carbon dioxide measurement module, formaldehyde measurement module and PM2.5 measurement module, wherein, the master module transmits data and commands to multiple slave modules through wireless communication, and the slave modules pass The measurement module connected to it collects the surrounding environmental parameters and transmits the environmental parameters to the host module through wireless communication. The host module implements unified management and real-time monitoring of all slave modules through the communication mode of polling extensions.

Described master single-chip microcomputer adopts STC12C5A60S2 chip, is used for receiving each measuring data that slave machine single-chip microcomputer transmits, and described slave machine single-chip microcomputer adopts STC12C5A60S2 chip, measures various indoor air quality parameters by each sensor module connected with it, and will measure The parameters are sent to the host microcontroller, and the reset module is composed of a capacitor and a resistor connected between the master/slave power supply module and the reset terminal of the master/slave microcontroller. In this embodiment, as shown in Figure 3 and Figure 4 , are the minimum system circuits of the master single-chip microcomputer and the slave single-chip microcomputer respectively, the clock circuits of the two systems are in the internal oscillation mode, the oscillation capacitance value is 30pF, and the crystal oscillator is 18.432MHz.

The master/slave power supply module adopts AMS1117-3.3 chip and AMS1117-5.0 chip, which respectively generate 3.3V voltage and 5V voltage for power supply, as shown in Figure 5, +12V voltage is converted into +5V voltage by AMS1117-5.0 for the first Level power supply, as shown in Figure 6, +5V voltage is converted into +3.3V voltage by AMS1117-3.3, and 3.3V voltage is generated for power supply.

The display module adopts a TFT2.8 touch color screen, which can better realize the man-machine interface and is used to display the measurement parameters of each slave module. As shown in FIG. 7, it is a circuit diagram of the display module.

Both the host communication module and the slave communication module adopt the XL4432-SMT wireless communication module, which is used for wireless data communication between the host microcontroller and the slave microcontroller. In this embodiment, the host module and the slave module pass through the wireless communication module. XL4432-SMT uses SPI interface for data transmission. The module size adopts 17*16.5mm, 1.27mm pitch single-row pin interface. It adopts the design of external antenna. It can send and receive 10 bytes at 1.2K rate in the open field The data volume test distance can reach up to 1200 meters. The wireless communication circuit based on this communication module is shown in Figure 8.

The temperature and humidity measurement module uses a DHT11 digital temperature and humidity sensor to measure the temperature and humidity parameter values in the indoor environment. In this embodiment, each DHT11 sensor is first calibrated in an extremely accurate humidity calibration room. The coefficients are stored in the OTP memory in the form of a program, and these calibration coefficients are called inside the sensor during the processing of the detection signal. This embodiment adopts a 4-pin single-row pin package, which is convenient for connection. The temperature and humidity measurement circuit is shown in Figure 9 .

Described carbon monoxide measurement module adopts ZYMQ-7 carbon monoxide measurement sensor, is used for measuring the carbon monoxide parameter value in indoor environment, in the present embodiment, as shown in Figure 10, is carbon monoxide measurement circuit, the gas sensor of carbon monoxide measurement sensor is provided with 6 needle pins, 4 of which are used for signal output, and 2 are used to provide heating current. The carbon dioxide measurement module adopts MG811 carbon dioxide measurement sensor, which is used to measure the carbon dioxide parameter value in the indoor environment. As shown in Figure 11, it is a carbon dioxide measurement circuit, and its element heating voltage is provided by an external circuit. When the surface temperature is high enough, The component is equivalent to a battery, and its two ends will output a voltage signal, and its value is in good agreement with the Nernst equation. When the component is measured, the impedance of the amplifier must be between 100-1000GΩ, and the test current should be controlled below 1pA.

The formaldehyde measurement module adopts MS1100 formaldehyde measurement sensor, which is used to measure the formaldehyde parameter value in the indoor environment, as shown in FIG. 12 , which is the formaldehyde measurement circuit of this embodiment.

The PM2.5 measurement module adopts the GP2Y1010AU0F dust sensor for measuring the PM2.5 parameter value in the indoor environment, as shown in Figure 13, which is the PM2.5 measurement circuit in this embodiment.

As shown in Figure 14, the main program of the mainframe module mainly completes the control function of the mainframe module. After turning on the power, it first initializes and then enters the main interface of the mainframe. There are various function touch keys on the mainframe interface. When touching a certain function key , enter the function interface and execute the corresponding function.

As shown in Figure 15, the host display module of this system uses a TFT2.8 color screen, which can display the measurement parameters of each slave, and has a touch function to achieve a better man-machine interface. After power on, firstly initialize the TFT, then initialize the touch controller, and then display the initial man-machine interface interface, in which you can select the touch button to enter the corresponding function interface and execute the corresponding function.

As shown in Figure 16, the main program of the slave module mainly completes the control function of the slave module. The main task of the slave module is to use various sensors to measure the values of various indoor environment parameters, and send each parameter value through the slave communication module Monitor the host module.

As shown in Figure 17, the slave module uses the DHT11 sensor to measure temperature and humidity parameters. DHT11 uses a single-bus data format, and the communication time is about 4ms. The data is divided into decimal parts and integer parts. Extended, now reads as zero. The operation process is as follows: a complete data transmission is 40bit, high bit first out.

Data format: 8bit humidity integer data + 8bit humidity decimal data + 8bi temperature integer data + 8bit temperature decimal data + 8bit checksum

When the data transmission is correct, the checksum data is equal to the last 8 bits of the result obtained by "8bit humidity integer data + 8bit humidity decimal data + 8bi temperature integer data + 8bit temperature decimal data". After receiving the start signal from the host module, DHT11 waits for the end of the start signal from the host module, and then sends an 80us low-level response signal. After the host module sends the start signal, after a delay of 20-40us, read the response signal of DHT11. After the host module sends the start signal, it can switch to the input mode or output high level, and the bus is pulled up by the pull-up resistor. .

As shown in Figure 18, the measurement of carbon monoxide, carbon dioxide, formaldehyde and PM2.5 in the slave module all need to AD convert the data measured by the sensor and send it to the microcontroller for processing. The present invention selects the self-contained AD of the single-chip microcomputer. STC12 series MCU has its own A/D conversion port in P1 port (P1.0-P1.7), and there are 8 channels of 10-bit high-speed A/D converters, and the speed can reach 250KHz. After power-on reset, the P1 port is a weak pull-up I/O port. The user can set any of the 8 channels as A/D conversion through software settings, and the ports that do not need to be used as A/D can continue to be used as I/O. oral use.

As shown in Fig. 19 and Fig. 20, data communication is performed between the master module and the slave module of the present invention through the wireless communication module XL4432_SMT. The master/slave communication module programming adopts the modular design idea, and each main function module in the system is compiled into an independent function and called by the main program. Functional modules include: initialization program (including initializing SPI and XL4432), wireless sending program, wireless receiving program, etc. The wireless sending program is responsible for writing data, and adding preamble, synchronization word, data length and CRC check byte to the data according to the communication protocol, forming a data packet and sending it out; the wireless receiving program is responsible for receiving and checking the data in the data packet. CRC byte to ensure the correctness of the received data.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a distributed indoor environmental quality detection system, is characterized in that, this system comprises host module and is distributed in indoor from machine module, and described host module is by host SCM, and connect the host power supply module of host SCM respectively, clock module, reseting module, display module and host computer communication module composition, described from machine module by from machine single-chip microcomputer, and connect respectively from machine single-chip microcomputer from electromechanical source module, clock module, reseting module, from machine communication module, temperature and humidity measurement module, carbon monoxide measurement module, carbon dioxide measurement module, formaldehyde measurement module and PM2.5 measurement module composition, wherein, data and command transfer are given multiple from machine module by communication by described host module, describedly by communication, environmental parameter is transferred to host module by the environmental parameter around the measurement module collection that is attached thereto from machine module, described host module realized all unified managements from machine module and monitoring in real time by the communication modes of poll extension set.

2. distributed indoor environmental quality detection system according to claim 1, it is characterized in that, described host SCM adopts STC12C5A60S2 chip, for receiving each measurement data sent from machine single-chip microcomputer, described from machine single-chip microcomputer employing STC12C5A60S2 chip, measure various IAQ (indoor air quality) parameter by each sensor assembly be attached thereto, and parameter will be recorded send to host SCM.

3. distributed indoor environmental quality detection system according to claim 1, is characterized in that, described master/slave electromechanical source module adopts AMS1117-3.3 chip and AMS1117-5.0 chip, and generation 3.3V voltage and 5V voltage are powered respectively.

4. distributed indoor environmental quality detection system according to claim 1, is characterized in that, described reseting module is made up of an electric capacity of cross-over connection between master/slave electromechanical source module and master/slave machine monolithic processor resetting end and resistance.

5. distributed indoor environmental quality detection system according to claim 1, is characterized in that, described display module adopts the touch color screen of TFT2.8, for showing each measurement parameter from machine module.

6. distributed indoor environmental quality detection system according to claim 1, it is characterized in that, described host computer communication module and all adopt XL4432-SMT wireless communication module from machine communication module, for carrying out wireless data communications at host SCM with between machine single-chip microcomputer.

7. distributed indoor environmental quality detection system according to claim 1, is characterized in that, described temperature and humidity measurement module adopts DHT11 digital hygro sensor, for the humiture parameter value in measuring chamber environment.

8. distributed indoor environmental quality detection system according to claim 1, it is characterized in that, described carbon monoxide measurement module adopts ZYMQ-7 carbon monoxide survey sensor, for the carbon monoxide parameter value in measuring chamber environment, described carbon dioxide measurement module adopts MG811 carbon dioxide survey sensor, for the carbon dioxide parameter value in measuring chamber environment.

9. distributed indoor environmental quality detection system according to claim 1, is characterized in that, described formaldehyde measurement module adopts MS1100 formaldehyde measurement sensor, for the formaldehyde parameter value in measuring chamber environment.

10. distributed indoor environmental quality detection system according to claim 1, is characterized in that, described PM2.5 measurement module adopts GP2Y1010AU0F dust sensor, for PM2.5 parameter value in measuring chamber environment.