CN207779519U

CN207779519U - A kind of 8 channel QCM test systems based on STM32

Info

Publication number: CN207779519U
Application number: CN201721507435.0U
Authority: CN
Inventors: 孙萍; 晏明国; 陈昱润; 冯兴; 张宇
Original assignee: Chengdu University of Information Technology; Sichuan Agricultural University
Current assignee: Chengdu University of Information Technology; Sichuan Agricultural University
Priority date: 2017-11-13
Filing date: 2017-11-13
Publication date: 2018-08-28
Anticipated expiration: 2027-11-13

Abstract

The utility model discloses a kind of 8 channel QCM test systems based on STM32, including：It will wait for that measurement information is converted to qcm sensor group, the controller for cutting the TCH test channel for changing qcm sensor group and the frequency counter for obtaining the frequency that the controller exports of frequency signal for immersing in object under test；The qcm sensor group connects the controller, and the controller connects the frequency counter.The utility model overcomes in the prior art since test object only has QCM itself, cannot provide contrast groups, can not the external temperature and humidity of synchronism detection defect, improve test generalization, intelligence degree.

Description

A kind of 8 channel QCM test systems based on STM32

Technical field

The utility model is related to QCM test systems technologies field, specifically a kind of 8 channel QCM based on STM32 are surveyed Test system.

Background technology

The development of quartz crystal microbalance (QCM) starts from the phase at the beginning of the sixties in last century, it is a kind of very sensitive quality Detecting instrument, for measurement accuracy up to nanogram level, specific sensitivity is 100 times high in the micro- balance of electronics of Gamma Magnitude, theoretically can be with The mass change measured is equivalent to the part of monolayer or atomic layer.Quartz crystal microbalance utilizes Quartz crystal resonant The piezoelectric property of device converts the variation of quartz crystal oscillator electrode surface quality to the frequency that quartz crystal oscillator circuit exports electric signal Variation, and then high-precision data are obtained by computer and other ancillary equipments.Existing QCM tests system includes starting of oscillation electricity Road, QCM crystal, the several components of frequency meter are able to record single QCM frequencies variation.But QCM is in test VOC (volatile organic gas Body) in the case of gaseous environment and heavy metal ion liquid phase environment, needs to monitor multigroup signal simultaneously and be compared.In addition QCM Temperature and humidity influence is also suffered from, external condition is required for synchronism detection, so the system of the frequency of current single QCM is Through that cannot meet the requirements.

Utility model content

Place aiming at the above shortcomings existing in the prior art, the technical problem to be solved by the present invention is to provide one kind 8 channel QCM tests system based on STM32 cannot be provided with overcoming in the prior art since test object only has QCM itself Contrast groups, can not the external temperature and humidity of synchronism detection defect.

The utility model technical solution used for the above purpose is：A kind of 8 channel QCM surveys based on STM32 Test system, including：It will wait for that measurement information is converted to the qcm sensor group of frequency signal, for cutting for immersing in object under test State the frequency counter of the controller for the TCH test channel for changing qcm sensor group and the frequency for obtaining the controller output； The qcm sensor group connects the controller, and the controller connects the frequency counter.

Further include the host computer for imaging of being drawn according to the frequency values in the frequency counter, the host computer connection The frequency counter.

The controller includes：Intelligent RF for switching qcm sensor group TCH test channel switchs, for providing comparison The QCM reference sources of signal, the intelligent differential frequency circuit for obtaining absolute difference frequency signal, MCU main controllers, for driving the MCU The minimum system of main controller, power circuit, Temperature Humidity Sensor, for external control instruction input touch screen and be used for data The storage circuit of storage；

Intelligent RF is switched for connecting the qcm sensor group；The intelligence differential frequency circuit connects the QCM reference sources It is switched with the intelligent RF；The power circuit connects the qcm sensor group；The MCU main controllers connect the intelligence RF switch, the intelligent differential frequency circuit connect the intelligent RF switch, the intelligent differential frequency circuit, the minimum system, The power circuit, the Temperature Humidity Sensor, the touch screen and the storage circuit.

Further include output interface, the output interface connects the serial ports of the MCU main controllers and the host computer.

The intelligent RF switch selects 8 to select 1 chip, is attached by 3 address wires with MCU main controllers.

The intelligence differential frequency circuit includes the first frequency dividing circuit, the second frequency dividing circuit and differential frequency circuit, first frequency dividing Circuit connects the intelligent RF switch, for that will carry out 16 frequency dividings from the test signal for the TCH test channel chosen；Described Frequency-halving circuit connects the QCM reference sources, for that will carry out 8 frequency dividings from the signal in the comparison channel；The difference frequency electricity The input terminal on road connects first frequency dividing circuit and second frequency dividing circuit, for export the test signal after 16 frequency dividings with The difference on the frequency of contrast signal after 8 frequency dividings.

The MCU main controllers are STM32F103 microcontrollers.

The utility model has the following advantages and advantageous effect：

1, the test object of the utility model not only has QCM itself, moreover it is possible to contrast groups are provided, it being capable of the external temperature of synchronism detection Degree and humidity.

2, the utility model cooperation host computer, intelligent RF switching switch, differential frequency circuit so that test generalization, intelligence Change degree improves.

Description of the drawings

Fig. 1 is the system connection block diagram of the utility model one embodiment；

Fig. 2 is the test fixture schematic diagram of the utility model one embodiment；

Fig. 3 is the circuit diagram of the intelligent RF switch of the utility model one embodiment；

Fig. 4 is the label 1. enlarged drawing of Fig. 3；

Fig. 5 is the label 2. enlarged drawing of Fig. 3；

Fig. 6 is the label 3. enlarged drawing of Fig. 3；

Fig. 7 is the intelligent differential frequency circuit schematic diagram of the utility model one embodiment；

Fig. 8 is the power circuit principle figure of the utility model one embodiment；

Fig. 9 is the circuit diagram of the Temperature Humidity Sensor of the utility model one embodiment；

Figure 10 is the schematic diagram of the storage circuit of the utility model one embodiment；

Figure 11 is the circuit diagram of the output interface of the utility model one embodiment；

Figure 12 is the circuit diagram of the touch screen of the utility model one embodiment.

Specific implementation mode

The utility model is described in further detail with reference to the accompanying drawings and embodiments.

As shown in Figure 1, a kind of 8 channel QCM based on STM32 described in the utility model embodiment test system, including Qcm sensor group, intelligent RF switch, intelligent differential frequency circuit, QCM reference sources, frequency counter, host computer, minimum system, electricity Source circuit, Temperature Humidity Sensor, MCU main controllers, storage circuit, output interface, touch screen.Under test gas group is test environment, Qcm sensor part in qcm sensor group is immersed in object under test, and such as gas, liquid is gone by sensor surface biomembrane It absorbs and specifies ingredient, it is quartz crystal microbalance then to cause mass change, QCM, can be Tiny Mass change transitions Cheng Pin Rate variation (while when testing multiple channels, the software in MCU main controllers carries out average value processing, obtains closest to actual value, Qcm sensor group can be changed with reading frequency, counter to calculate mass change, then calculate the concentration variation of gas or liquid)；Intelligence RF switch is used to switch the channel of qcm sensor group, and intelligent differential frequency circuit is logical with comparison for directly comparing TCH test channel The difference in road；Switching of the intelligent RF switch for TCH test channel, chip can only be tested Rapid Circulation a group by a group；Intelligent difference frequency Circuit does difference frequency for test signal and contrast signal, and what high-frequency circuit was selected is hardware difference frequency, and output is exactly exhausted after changing To value.Frequency counter is used to obtain the frequency of differential frequency circuit output；Host computer can directly read the frequency in frequency counter Rate value, for imaging of drawing；Minimum system for drive MCU main controllers work, power module for control MCU main controllers and Qcm sensor group is powered, 12V and 3.3V voltages are provided；Temperature Humidity Sensor is connect by IIC modes with MCU main controllers, is read The humiture of current environment is taken, environmental monitoring is used for；Storage circuit is connected to by IIC modes on MCU main controllers, and setting is stored Value；In addition system carry SD card is used for the display and control of touch screen；Output interface is connected on the serial ports of MCU main controllers, is used for The serial communication of MCU main controllers and host computer, prevailing transmission Current Temperatures, humidity, TCH test channel, board information data.It touches Screen provides human-computer interaction interface, and people can select dedicated tunnel test, changing interface, display switching etc. by touch screen.QCM joins Source is examined for providing contrast signal, when testing gas or liquid, is easy to be influenced by temperature, in order to eliminate in test process Temperature influences, and can stay one group of test TCH test channel in standard environment, this group of standard signal is exactly reference signal, other test letters It number is compared with this group of standard signal, it is convincing.MCU main controllers are for switch test channel and obtain absolute difference frequency letter Number, hardware-efficient rate divides difference frequency, reduces main controller workload of operation, improves arithmetic speed.

As shown in Fig. 2, a kind of test of 8 channel QCM test systems based on STM32 described in the utility model embodiment Tooling schematic diagram is formed by connecting according to the system block diagram of Fig. 1, wherein qcm sensor group is placed in environment to be measured, QCM sensings Device group is connected by radio frequency line, and controller (embedded controller) is switched over by intelligent RF switch；Intelligent differential frequency circuit After getting frequency, frequency counter reads frequency, and embedded controller carries out serial communication with computer, sends temperature, wet Degree, TCH test channel, command information are to computer.Embedded controller is exactly STM32 microcontrollers described in the utility model and other The set of peripheral circuit.

As shown in Figure 3-4, the intelligence of a kind of 8 channel QCM test systems based on STM32 described in the utility model embodiment The circuit diagram of energy RF switch, wherein U16, U17, U18, U19, U20, U21, U22, U23 is that the radio frequency of qcm sensor group connects Mouthful；JSP1, JSP2, JSP3, JSP4, JSP5, JSP6, JSP7, JSP8 are the power interfaces of qcm sensor group；U24 be 8 select it is 1 logical Chip, U25 are test ox shape interfaces, and U26 is that 5V turns 3.3V electrical level transferring chips, and U30 and U32 are frequency dividing chips, realize that reading is defeated Go out the scaling down processing of frequency, U32 is accomplished that 16 frequency dividings, U30 are accomplished that 8 frequency dividings；U31 is XOR gate, and U29 is that 4 channel D are touched Device is sent out, according to nyquist frequency phase convolution, is used for the output of difference frequency.

Lead to as shown in figure 5, a kind of 8 channel QCM based on STM32 described in the utility model embodiment test the 8 of system Road switching circuit figure grade 2. enlarged drawing, wherein U30 and U32 are frequency dividing chips, realize the scaling down processing of read output frequency, U32 It is accomplished that 16 frequency dividings, U30 are accomplished that 8 frequency dividings；U31 is XOR gate, and U29 is 4 channel d type flip flops, is used for the acquisition of difference frequency And it exports.

Lead to as shown in fig. 6, a kind of 8 channel QCM based on STM32 described in the utility model embodiment test the 8 of system Road switching circuit figure grade 3. enlarged drawing, wherein U24 are that 8 to select 1 obturator piece, U25 be test ox shape interface, and U26 is that 5V turns 3.3V Electrical level transferring chip, thus circuit structure switching of the chip to channel can be realized.

As shown in fig. 7, a kind of intelligence of 8 channel QCM test systems based on STM32 described in the utility model embodiment Differential frequency circuit schematic diagram, frequency reduces after frequency dividing, and hardware chip processing speed is just enough, then 10M frequencies first divide carries out difference again Frequency output absolute change frequency values, chip may know that practical absolute frequency value by high-speed sampling.Wherein F0 and F1 is desirable Two signals of difference frequency are obtained, and F0 ratios F1 is bigger, the operation principle of circuit can be understood by means of sampling thheorem； XOR gate is regarded as a modulator, with F1 modulate F0, output comprising the sum of F0 and F1 and difference, then acquire this frequency Difference signal generates an aliasing frequency, and the frequency and nyquist frequency phase convolution, i.e. output frequency are poor：

FD=2F0- (F0+F1)=F0-F1

Certainly, output can also change, if F1=F0/n (being generated with frequency divider), FD=F0 (1-1/n) is if F1=F 0*m/n (is generated) with multiplier, then FD=F0 (1-m/n).

As shown in figure 8, a kind of power supply of 8 channel QCM test systems based on STM32 described in the utility model embodiment Circuit diagram, wherein JP4 are common circular interfaces, and JP2 is used to pick out the port of 12V power supplys, and U4 is switching power source chip, L1, D1, C1 form switched integration circuit, R7, R8, R9, R10 composition output primary electrical voltage regulator circuit, and control exports 5V power supplys, It is used to QCM systems；U5 is linear regulator chip, and 5V voltages are accessed in front end, and rear end exports 3.3V and used to SCM system, C19, C20, C21 are filter capacitors.

As shown in figure 9, a kind of 8 channel QCM based on STM32 described in the utility model embodiment test the warm and humid of system The circuit diagram of sensor is spent, wherein U17 is humiture one chip, can export data of the Temperature and Humidity module simultaneously.

As shown in Figure 10, a kind of 8 channel QCM based on STM32 described in the utility model embodiment test depositing for system The schematic diagram on storing up electricity road, wherein U15 are power down storage chips, and the value for storing setting, R39, R40 are pull-up resistors, are passed through IIC and single chip communication.U12 is SD card interface, and for storing the character library needed for liquid crystal display, R35, R36, R37, R38 are pull-up Resistance, SD card are connect by SPI communication with microcontroller.

As shown in figure 11, a kind of 8 channel QCM based on STM32 described in the utility model embodiment test connecing for system The schematic diagram of mouth circuit, wherein U8 are USB ports, and U7 is that TTL turns serial port chip, and Y3, C27, C28 form the clock electricity of serial port chip Road, C26 are the start-up capacitances of U7, and Q1, Q2 form a key download circuit, and R22, R23, R24, R41 are current-limiting resistances, and D2 is counnter attack Connect diode.

As shown in figure 12, a kind of 8 channel QCM test systems based on STM32 described in the utility model embodiment is tactile The circuit diagram of screen is touched, wherein touch screen uses 16 Parallel Interface Communications, and microcontroller inside FSMC_D0~FSMC_D15 is for touching Touch screen data transmission；The touch control order of touch screen is realized by T_MISO, T_MOSI, T_SCK, T_PEN, T_CS.

The utility model is not limited to above-mentioned preferred forms, anyone can obtain under the enlightenment of the utility model Other various forms of products, such as the variation of number of channels, the variation of main controller, however, making in its shape or structure any Variation, it is every that there is technical solution identical or similar to the present application, it all falls within the scope of protection of the utility model.

Claims

1. a kind of 8 channel QCM based on STM32 test system, which is characterized in that including：It will be waited for for immersing in object under test Measurement information be converted to the qcm sensor group of frequency signal, TCH test channel for switching the qcm sensor group controller and Frequency counter for the frequency for obtaining the controller output；The qcm sensor group connects the controller, the control Device processed connects the frequency counter.

2. a kind of 8 channel QCM based on STM32 according to claim 1 test system, which is characterized in that further include using In the host computer for imaging of being drawn according to the frequency values in the frequency counter, the host computer connects the frequency counter.

3. a kind of 8 channel QCM based on STM32 according to claim 2 test system, which is characterized in that the control Device includes：For switch the intelligent RF switch of qcm sensor group TCH test channel, the QCM reference sources for providing contrast signal, For obtain the intelligent differential frequency circuit of absolute difference frequency signal, MCU main controllers, the minimum system for driving the MCU main controllers, Power circuit, Temperature Humidity Sensor, the touch screen for external control instruction input and the storage circuit for data storage；

Intelligent RF is switched for connecting the qcm sensor group；The intelligence differential frequency circuit connects the QCM reference sources and institute State intelligent RF switch；The power circuit connects the qcm sensor group；The MCU main controllers connect the intelligent RF Switch, the intelligent differential frequency circuit connect the intelligent RF switch, the intelligent differential frequency circuit, the minimum system, described Power circuit, the Temperature Humidity Sensor, the touch screen and the storage circuit.

4. a kind of 8 channel QCM based on STM32 according to claim 3 test system, which is characterized in that further include defeated Outgoing interface, the output interface connect the serial ports of the MCU main controllers and the host computer.

5. a kind of 8 channel QCM based on STM32 according to claim 3 test system, which is characterized in that the intelligence RF switch selects 8 to select 1 chip, is attached by 3 address wires with MCU main controllers.

6. a kind of 8 channel QCM based on STM32 according to claim 3 test system, which is characterized in that the intelligence Differential frequency circuit includes the first frequency dividing circuit, the second frequency dividing circuit and differential frequency circuit, and first frequency dividing circuit connects the intelligence RF switch, for 16 frequency dividings will to be carried out from the test signal for the TCH test channel chosen；Second frequency dividing circuit connects institute QCM reference sources are stated, 8 frequency dividings are carried out for the contrast signal will to be come from；The input terminal connection described first of the differential frequency circuit The frequency of contrast signal after frequency dividing circuit and second frequency dividing circuit, the test signal for being used to export after 16 frequency dividings and 8 frequency dividings Rate is poor.

7. a kind of 8 channel QCM based on STM32 according to claim 3 test system, which is characterized in that the MCU master Control device is STM32F103 microcontrollers.