CN109902060A - Multi-path data acquiring system based on USB communication - Google Patents
Multi-path data acquiring system based on USB communication Download PDFInfo
- Publication number
- CN109902060A CN109902060A CN201910052073.8A CN201910052073A CN109902060A CN 109902060 A CN109902060 A CN 109902060A CN 201910052073 A CN201910052073 A CN 201910052073A CN 109902060 A CN109902060 A CN 109902060A
- Authority
- CN
- China
- Prior art keywords
- data
- converter
- usb
- microcontroller
- usb communication
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004891 communication Methods 0.000 title claims abstract description 13
- 238000006243 chemical reaction Methods 0.000 claims description 43
- 238000013461 design Methods 0.000 claims description 15
- 238000005516 engineering process Methods 0.000 claims description 11
- 239000003990 capacitor Substances 0.000 claims description 9
- 238000013459 approach Methods 0.000 claims description 6
- 230000002457 bidirectional effect Effects 0.000 claims description 3
- 239000003381 stabilizer Substances 0.000 claims description 2
- 238000013480 data collection Methods 0.000 abstract description 9
- 230000005540 biological transmission Effects 0.000 abstract description 5
- 238000012423 maintenance Methods 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 17
- 230000009466 transformation Effects 0.000 description 11
- 230000006870 function Effects 0.000 description 9
- 230000008569 process Effects 0.000 description 7
- 238000005070 sampling Methods 0.000 description 7
- 230000008901 benefit Effects 0.000 description 5
- 230000010354 integration Effects 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000011161 development Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000013481 data capture Methods 0.000 description 1
- 238000013500 data storage Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 210000004209 hair Anatomy 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000013139 quantization Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Analogue/Digital Conversion (AREA)
Abstract
The present invention provides a kind of multi-path data acquiring systems based on USB communication, including data acquisition module, the data acquisition module includes A/D converter, voltage follower and microcontroller, after analog input signal is filtered by the voltage follower, it is output to the A/D converter, the microcontroller is exported the digital signal after A/D converter is converted to computer and is shown by USB control chip, the present invention is easy for can be realized low cost, high reliability, the external data collection system of multiple spot, this can not only improve the data transmission bauds of system, the flexibility of system can also be enhanced, be conducive to the maintenance of system simultaneously；And data communication can be carried out by usb data bus interface and PC machine, sampled data is displayed in real time and stored in PC machine, and the multichannel data that this system can be applied to a variety of occasions such as laboratory or industry spot acquires in real time.
Description
Technical field
The present invention relates to data collecting fields, and in particular to the multi-path data acquiring system communicated based on USB.
Background technique
In industrial production and the every profession and trade of scientific and technical research, usually various data are adopted using PC or industrial personal computer
Collection.Data acquisition technology is the important branch of information science, is the information technologies knot such as sensor, signal acquisition, storage and processing
It closes.Temperature, pressure existing for the external world, liquid level etc. are converted into analog or digital signal, then is transmitted to computer and makees into one
This process of processing is walked, i.e., " data acquisition ".Data acquisition is in industrial or agricultural, medical and health, ecological environment, space flight and aviation,
Military affairs, the fields such as meteorology are widely used, can be by signal measurement, processing, control and management, realize survey, control,
The automation and systematization of pipe often need to adopt various signals in industrial production and the every profession and trade of scientific and technical research
Collection, such as liquid level, temperature, pressure, frequency.But traditional acquisition mode is the installation data capture card in PC machine or industrial personal computer,
In this way not only installation trouble, vulnerable to the interference of environment in cabinet, but also due to by computer slot quantity and address,
The limitation of interrupt resources, it is impossible to mount many equipment.
The beginning of the seventies, with the development of computer technology and large scale integrated circuit, especially microprocessor and high-speed a/d
Major transformation has occurred in the appearance of converter, data collection system structure.Originally by the Digital Logical Circuits that integrates on a small scale and
The acquisition system that the acquisition system of hardware program controller composition is microprocessor controlled is replaced.Because having been gone by microprocessor
At process control, data processing and most of logical operation greatly improve the flexibility of system and reliability, system it is hard
The reconstruction expenses of part cost and system greatly reduce.
Data collection system is generally by signal conditioning circuit, sampling hold circuit, A/D conversion chip, microprocessor composition.
Structural block diagram is as shown in Figure 1.
Wherein signal conditioning circuit, it is important composition portion in bridge and TT&C system between sensor and A/D
Point.The major function of signal condition is:
(1) standardization industrial instrument generallys use 0~10Ma, 4~20mA signal, for the input form with A/D at present
It is adapted, it is necessary to be transformed into voltage signal through I/V.
(2) certain measuring signals may be non-voltage, such as thermal resistance, these non-voltage signals must become voltage
Signal, also some signals are weak voltage signal, such as thermocouple signal, it is necessary to amplify, filter, these processing include signal form
Transformation, range adjustment, ambient compensation, linearisation etc..
(3) under certain mal-conditions, common-mode voltage interference is very strong, if common mode electrical level is up to 220V, does not use doing for isolation
Method is unable to complete the task of data acquisition, therefore, it is necessary to depending on the site environment, considers the inhibition of common mode interference, in addition using every
It is isolated from measure, including ground wire, be isolated between road etc..
Summary of the invention
In order to solve above-mentioned insufficient defect, the present invention provides the multi-path data acquiring system communicated based on USB, this hairs
Bright to be easy for can be realized low cost, high reliability, the external data collection system of multiple spot, this can not only improve system
Data transmission bauds, moreover it is possible to enhance the flexibility of system, while be conducive to the maintenance of system；And it can be connect by usb data bus
Mouthful carry out data communication with PC machine, display in real time and store sampled data in PC machine, this system can be applied to laboratory or
The multichannel data of a variety of occasions such as industry spot acquires in real time.
The present invention provides the multi-path data acquiring system communicated based on USB, including data acquisition module, the data are adopted
Collecting module includes A/D converter, voltage follower and microcontroller, and analog input signal is filtered by the voltage follower
Afterwards, it is output to the A/D converter, the microcontroller is controlled the digital signal after A/D converter is converted by USB
Chip is exported to computer and is shown.
Above-mentioned acquisition system, wherein the A/D converter uses the TLC2543C of TI company production, 11 12, tunnels
The serial A/D converter of switching capacity Approach by inchmeal.
Above-mentioned acquisition system, wherein the voltage follower by 3 LM324 four high guaily unit circuits and several resistance and
Made of capacitor design.
Above-mentioned acquisition system, wherein the microcontroller uses 8 8-digit microcontrollers of CMOS technology manufacture.
Above-mentioned acquisition system, wherein conversion end EOC, I/O clock, the serial data input of the TLC2543
AD_DIN, serial data output terminal AD_OUT piece select CS be separately connected single-chip microcontroller parallel bidirectional I/O mouth 1 pin P1.0,
P1.1、P1.2、P1.3、P1.4。
Above-mentioned acquisition system, wherein 5V reference voltage source needed for the TLC2543 then pass through LM336 voltage-stabiliser tube and
12V power supply is transformed into 5V by slide rheostat.
The present invention provides have the advantages that may be implemented pair based on the multi-path data acquiring system that USB is communicated
The acquisition of 14 tunnel analog signals, then as needed by 14 tunnel analog signals any road or multiple signals carry out analog-to-digital turn
It changes, and by USB interface, is shown in real time in PC machine；Using P89C51RA2 as core control part, its function
It is more complete, it can satisfy the needs of system design.Single-chip microcontroller controls acquisition, display, the transmission of data, it is whole system
Core, and TLC2543 is then the A/D conversion chip of this data collection system, it is completed using switched capacitor successive approximation technique
A/D conversion process can save the I/O resource of 51 series monolithics, and moderate, resolution ratio due to being serial input structure
It is higher.
Detailed description of the invention
Upon reading the detailed description of non-limiting embodiments with reference to the following drawings, the present invention and its feature, outer
Shape and advantage will become more apparent upon.Identical label indicates identical part in all the attached drawings.Not deliberately proportionally
Draw attached drawing, it is preferred that emphasis is show the gist of the present invention.
Fig. 1 is existing data collection system structural block diagram.
Fig. 2 is usb data acquisition system overall construction drawing involved in the present invention.
Fig. 3 is the data collection system structure chart being related in the present invention.
Fig. 4 is the interface circuit figure of TLC2543 and single-chip microcontroller in the present invention.
Fig. 5 is data collection system flow chart in the present invention.
Specific embodiment
In the following description, a large amount of concrete details are given so as to provide a more thorough understanding of the present invention.So
And it is obvious to the skilled person that the present invention may not need one or more of these details and be able to
Implement.In other examples, in order to avoid confusion with the present invention, for some technical characteristics well known in the art not into
Row description.
In order to thoroughly understand the present invention, detailed step and detailed structure will be proposed in following description, so as to
Illustrate technical solution of the present invention.Presently preferred embodiments of the present invention is described in detail as follows, however other than these detailed descriptions, this
Invention can also have other embodiments.
Referring to Fig.1 shown in-Fig. 5, the multi-path data acquiring system provided by the invention based on USB communication, including data are adopted
Collect module, the data acquisition module includes A/D converter, voltage follower and microcontroller, and analog input signal passes through institute
After stating voltage follower filtering, it is output to the A/D converter, the microcontroller is the number after A/D converter is converted
Word signal is exported to computer and is shown by USB control chip, and emphasis discusses data acquisition module in the present invention
Working principle.A/D switch technology, temperature control technology, microprocessor and USB is mainly utilized in the data collection system of this USB
Technology is got up along with the rapid development of USB technology and the development of new data acquisition technology.Collected number
PC machine is sent to and real-time display comes out, the conversion of waveform fidelity performance and A/D converter according to by host interface (USB port)
Rate, resolution ratio and precision are closely related.A/D conversion rate is higher, and the resolution ratio of the waveform of reproduction is also higher: A/D conversion
Device digit is more, and precision is higher, and waveform fidelity is higher.This system overall construction drawing is as shown in Figure 2.Wherein temperature controls skill
The realization of art, USB technology and data acquisition waveform is completed by third-party design, is not being introduced here.
In the present invention, shown in Fig. 3, after 11 road analog input signals are filtered by voltage follower, it is output to A/D conversion
Digital signal after A/D converter is converted is controlled chip by USB and exported to computer by device, microcontroller, while can
To realize the display of data on computers；And usb host and display portion then pass through output interface and show in PC machine, use
Software carrys out the waveform of simulative display input signal.It can control the start and stop of A/D converter, the access of data access unit, USB simultaneously
The work of peripheral hardware chip, the amplification for showing figure and diminution etc..
In the present invention, the enhanced 80C51 single-chip microcontroller P89C51RA2 released using Philips company, this chip packet
Containing 8K can parallel programmable non-volatile FLASH program storage, and can realize to device tandem system programming (ISP) and
(IAP) is programmed in.In-system programming ISP (In-System Programming) permits when MCU is mounted on user's plate
Download new code in family allowable.IAP (In-Application Programming) is programmed in the application, MCU can be in system
Middle acquisition fresh code simultaneously reprograms oneself, and this method, which allows to connect by modem, to be carried out in long-range programming piece
The serial loading procedure BootLoader of cured default allows in ROM.ISP is deposited program code loading Flash by UART
Reservoir and loading procedure is not needed in Flash code then, for IAP user program by using the standardization program in ROM in piece
Flash storage is wiped and is reprogramed.The device can be by the method for multiple programming or in-system programming to one
Flash are programmed, thus 6 clocks of selection or 12 clock modules.It furthermore can also be by clock-control register CKCON
X2 6 clocks of selection or 12 clock modules, in addition when being in 6 clock module, peripheral function can choose a machine cycle 6
Clock or 12 clocks, this is to carry out selection by CKCON register.
The Series of MCU be the derivation device of 80C51 microcontroller be using Advanced CMOS Process manufacture 8 it is micro-
Controller, instruction system are identical with 80C51.The device has 4 groups 8 I/O mouthfuls, 3 16 bit timings/counters, multiple interrupt
- 4 interrupt priority level of source-nesting interrupt structure, 1 enhanced UART piece internal oscillator and sequence circuit and growth data storage
64K, PCA (programmable counter array), hardware watchdog timer in device piece.Newly-increased characteristic becomes P89C51RA2
Microcontroller with better function, to preferably support to need to use pulsewidth modulation, High Speed I/O, incremented/decremented tally function
(such as motor control) application.
In the present invention, mould-number conversion chip selection specifically includes:
Modulus conversion technique have developed rapidly in recent years, and conversion speed is also greatly while function enhancing, lower power consumption
It improves, conversion frequency is increased to tens MHz from several hundred kHz, and chip is also relatively cheap, and use is also increasingly extensive.Its A/D conversion
The type of device is also more and more, and use widely has at present: successive approximation type a/d converter, remainder feedback comparison expression A/D are converted
Device, double integration A/D converter, V/F transform A/D converter and ∑-Δ formula A/D converter etc..
(1) successive approximation type a/d converter: speed is high, and external application component is also few, most of single-chip integration A/D conversions
Device chip mostly uses such mode.But should be equipped with sampling holder to fast-changing input signal just can guarantee conversion accuracy
It is required that.In addition, A/D converter itself acts on the noise unrestraint in input signal, it is necessary to anti-interference using additional software and hardware
Measure could inhibit most of random disturbances in input signal.
(2) remainder feeds back comparison expression A/D converter: this conversion regime resolution ratio is very high, and quantization error is small, conversion accuracy
It is high.The speed of this conversion regime is mainly limited by two factors: first is that circulation carries out the time of voltage digital conversion every time；
Second is that the settling time of remainder analog voltage.Currently, A/D chip in this way, by being aided with some other skills
Art measure, conversion speed is still than faster.
(3) double integration A/D converter: strong antijamming capability, conversion accuracy with higher, circuit structure is simple, coding
Convenient, but conversion rate is low, it is not high to be usually used in rate request, in the higher measuring instrument instrument of required precision.
(4) due to applying integrating capacitor, V/F transform A/D converter: there is good interference free performance, good
The linearity and high resolution ratio, circuit structure are simple.The disadvantage is that conversion rate is low, in the detection channel of some non-rapid more
To use V/F transform A/D converter replace common A/D converter.
(5) ∑-Δ formula A/D converter: it has the feature fed back and compared with integration type concurrently, has stronger anti-interference energy
Power, the advantage that quantizing noise is small, high resolution and the linearity are good.Conversion rate is also above integration type ADC, therefore, ∑-Δ formula
A/D converter is the preferential selection controlled for outdoor intelligent instrumentation and industrial process parameter detecting.
In the present system, comprehensively consider according to actual needs with cost performance, using TI company produce TLC2543C, 11
12 bit switch capacitor Approach by inchmeal serial a/d converter of road, sample rate 66kbit/s, 10us is converted in operating temperature range
Time.There are three control signals for tool: piece choosingInput/output clock I/O CLOCK and address input end AD_DIN.It
It can also be communicated by a serial 3-state output AD_OUT and primary processor or the serial port of its periphery, export Change-over knot
Fruit.This device can be from host high speed transmission data.Other than the converter of high speed and general control ability, this device has one
14 channel Port Multipliers in a piece can arbitrarily select in 11 input channels or 3 built-in self testing (SELF-TEST) voltages
Select one.Sample-hold is automatic.In conversion end, conversion end EOC output end gets higher the completion to indicate conversion.
Converter in this device combines the reference voltage of externally input difference high impedance, have simplifying rate conversion, scale and
The characteristics of analog circuit is isolated with logic circuit and power supply noise.The design of switching capacity can make to have over the entire temperature range
Lesser transformed error.This multichannel, the TLC2543C device of small size, linearity error is small (± 1LSB max), saves I/O money
Source, cost is relatively low, the exploitation especially suitable for single-chip data acquisition system.Wherein, inside TLC2543 by channel to channel adapter,
Input address register, sampling hold circuit, 12 analog-digital converters, output register, simultaneously → string converter and control
7 parts such as logic circuit form.Channel to channel adapter according to the address choice input channel stored in input address register, and
Signal in input channel is sent in sampling hold circuit, is then converted the analog quantity of sampling in 12-bit digital-to-analog converter
It at digital quantity, is stored in output register, these data are converted into serial data by parallel → serial convertor, by AD_
OUT terminal is output in microprocessor.
In the present invention, the interface circuit mode of TLC2543 and single-chip microcontroller are as follows: in 80C51 series microprocessor not
Band SPI or identical interface capability, in order to TLC2543 analog-digital converter interface, need to be synthesized the operation of SPI with software,
Data transfer rate declines in this way, is controlled by microprocessor instruction cycle time, thus is influenced by the clock frequency of microprocessor.
Therefore the highest of microprocessor frequency always is selected, as far as possible to reduce instruction cycletime, optimized interface data transmission speed
Rate；As shown in figure 4, the interface circuit of TLC2543 and single-chip microcontroller.Conversion end EOC, I/O clock, the serial number of TLC2543
According to input terminal AD_DIN, serial data output terminal AD_OUT piece select CS be separately connected single-chip microcontroller parallel bidirectional I/O mouth 1 pin
P1.0、P1.1、P1.2、P1.3、P1.4。
When designing and producing it is noted that item:
(1) power decoupling
When 12 A/D devices this using TLC2543, the power end of each analog IC must use the pottery of a 0.1 μ F
Porcelain capacitance connection is used as decoupling capacitor to ground.In the biggish environment of influence of noise, it is proposed that each power supply and ceramic condenser end are simultaneously
The tantalum capacitor for joining a 10 μ F, can reduce the influence of noise in this way.
(2) it is grounded
To analog device and digital device, the earth loop of power supply must be separated, to prevent the noise current of numerical portion
It is introduced by simulation earth-return, generates noise voltage, to generate interference to analog signal.All earth loops have centainly
Impedance, therefore ground wire will as wide as possible or property-line plane, to reduce impedance, line should be as short as possible, if using opening
Powered-down source, then Switching Power Supply will be far from analog device.
(3) circuit board wiring
Using it is certain when TLC2543 it is noted that circuit board wiring, the wiring of circuit board will ensure digital signal and simulation
Signal separates, and artificial line and digital line especially clock cable cannot be parallel to each other, can not below TLC2543 chip cloth
Digital signal line.
In the present invention, the design method of voltage follower are as follows: if voltage follower by 3 LM324 four high guaily unit circuits and
Made of dry resistance and capacitor design.Using LM084 chip when design, but sent out when debug circuit
Existing LM084 calorific value is too big, in the case where there is no problem for inspection circuit, since LM324 calorific value is relatively small and function
It is essentially identical, so finally using LM324.Since LM324 four high guaily unit circuit has supply voltage range wide, quiescent dissipation
It is small, can single supply use, it is cheap the advantages that, therefore be widely used in various circuits.
In the present invention, select Altium company 6 DXP electronic design system software of Altium Designer come into
Row circuit board designs and produces.Altium Designer 6 is the board grade designing system of newest complete set, is really realized
It is integrated in single application program.Altium Designer 6 allows user to can choose optimal design approach to come by oneself
Desired mode works.Windows XP and Windows has been fully utilized in 6 line map designing system of Altium Designer
The advantage of 2000 platforms has improved stability, the graphing capability of enhancing and superpower user interface.Wherein usb data is adopted
The power supply of collecting system uses external 12V power supply power supply, and then to pass through LM336 steady for 5V reference voltage source needed for chip TLC2543
12V power supply is transformed into 5V by pressure pipe and slide rheostat.
In PCB design of the invention, wiring is to complete the important step of product design, in entire PCB, with wiring
Design process limits highest, and skill is most thin, workload is maximum.The mode of wiring also there are two types of: self routing and interactive wiring.
Both hand layouts, and external electromagnetic interference in order to prevent are routed due to the design using single sided board and with interactive mode, are adopted
Non-closed protection circuit is constituted with relatively wide copper wire with circuit board outside.Inside circuit, directly with remaining on plate
The large area in space is grounded to improve the stability of circuit signal.
In the present invention, the software programming of usb data acquisition system includes: the course of work of TLC2543
The course of work of TLC2543 is divided into two periods: I/O period and change-over period.
(1) the I/O period
The I/O period is defined by the I/O CLOCK that outside provides, and is continued 8,12 or 16 clock cycle, is decided by selected
Data length.Device carries out two kinds of operations after entering the I/O period.Firstly, the rising edge of preceding 8 pulses in I/OCLOCK, with
The leading mode of MSB inputs 8 bit data streams to input register from the end DATA INPUT.Wherein first 4 are analog channel address, control
It makes 14 channel analogy Port Multipliers and is gated from 11 simulation inputs and 3 close beta voltages and be sent to sampling hold circuit all the way,
The circuit is sampled since the failing edge of the 4th I/O CLOCK pulse to signals selected, to the last an I/O
The failing edge of CLOCK pulse.The clock pulses number and output data length (digit) in I/O period are simultaneously by input data
D3, D2 are selected as 8,12 or 16.When working in 12 or 16, after preceding 8 clock pulses, DATA INPUT is invalid.
Secondly, in 8,12 or 16 data of DATA OUT terminal Serial output.WhenWhen remaining low, first data appears in EOC
Rising edge.If conversion byControl, then first output data occursFailing edge.This serial data is preceding primary
Conversion as a result, each subsequent bit after first output data has subsequent I/O clock falling edge to export.
(2) change-over period
After the last one I/O CLOCK failing edge in I/O period, EOC is lower, and sampled value remains unchanged, conversion week
Phase, piece Internal Translator carries out Approach by inchmeal A/D conversion to sampled value, when work is by the inside synchronous with I/O CLOCK
Clock system.It converts rear EOC to get higher, transformation result is latched in output data register, is exported to next I/O period.
I/O period and change-over period alternately, so as to reduce influence of the external digital noise to conversion accuracy.
In the present invention, referring to Figure 5, capture program is designed as a cyclic program, complete in a cycle with
Lower work: A/D converter receives command word from single-chip microcontroller by AD_DIN and chooses channel, clock and polarity, subsequently into
In the sampling period, after the last one I/O CLOCK failing edge in I/O period, EOC is lower, and sampled value is kept not
Become, the change-over period, piece Internal Translator carries out Approach by inchmeal A/D conversion to sampled value, and work is by synchronous with I/O CLOCK
Internal clocking control.It converts rear EOC to get higher, transformation result was latched in output data register, to next I/O weeks
Phase output.When next I/O period starts, A/D converter is by last transformation result from AD_OUT serial input to list
In the external memory of piece machine.
In the present invention, A/D Transformation Program designs are as follows:
Using function init_ADC (m | OUTPUTLENGHT_12 | UNIPOLAR) to A/D core in main program Mainloop
Piece is initialized, and initial channel, clock module and the polarity of system are defined.Since TLC2543 has 3 kinds of clock modules point
Not Wei 8,12 and 16 clocks, wherein defaulting is 12 clocks, for the consideration general to system, the handle in A/D conversion routine
It is designed to optional clock module.
In data acquisition system, TLC2543 output result is arranged to 12 unsigned int numbers, and output sequence is high
Position it is preceding and be unipolarity.In each A/D conversion process, TLC2543 will be read from serial input terminal AD_DIN by list
The control word of piece machine input samples some or multiple channels select, and then progress A/D conversion, transformation result are stored into
Output data register AD_OUT.In next I/O period, by the outer of data output end AD_OUT Serial output to single-chip microcontroller
Portion's register.But since acquisition is 12-bit data, for 8 single-chip microcontrollers, to be stored in two memory address, therefore need
Single-chip microcontroller is sent into main program using returning again to after AdResult=datah*256+datal synthesis.
This program not only realizes the data acquisition of 14 tunnel analog signals but also can arbitrarily select one or more progress
Data conversion, simultaneously synthesizing SPI function enable TLC2543A/D conversion chip and P89C51RA2 single-chip microcontroller to be rapidly performed by
Normal communication.But there is also certain problem, need to be further improved in follow-up work.The detailed procedure of A/D conversion is shown in
Appendix A.
Following problem is paid attention in the programming of TLC2543:
(1) input and output duty cycle is 12 clock signals, with the entrance of 12 clock signals, TLC2543
12 digits sent out of AD_OUT pin, for the A/D change data of a upper duty cycle, and this data is adopting for what channel
Collection amount, first four for being sent into the control word of TLC2543 from AD_DIN pin depending on a upper duty cycle.So in system
In the first job period after electricity, the data taken out from AD_OUT are nonsensical.
(2) the low 4 decision output data length and format of control word generally should not be in operational process after initial setting
Middle change, in order to avoid data corruption.And recycled in the duty cycle, if data are not handled properly in accumulator A, it is easy illegal control
Word processed brings TLC2543 into, causes output data format mistake, and this point should be paid special attention to.
(3)End controls transition initialization and the input and output of TLC2543.HereinEnd control conversion process,
Must be maintained in inputoutput data process it is low, i.e., during inputting 12 clock signalsAfter must keeping 0,Hold quilt
Height is set, to makeVariation from high to low, and generate the subsequent work period.When end is set to high, it is connected with TLC2543
Other three lines are in high-impedance state, can be used for other routes, when hardware design, may be designed as share wires, when software programming, root
According toSituation determines that who uses these routes.
(4) transformation result is exported with binary mode, when input voltage is equal to VREF+When, transformation result is 12
" 1 ", i.e. (1,111 1,111 1111), when input voltage is equal to VREF-When, transformation result be 12 " 0 ", i.e., (0,000 0000
0000), when input voltage is equal to (VREF++VREF-When)/2, transformation result is (1,000 0,000 0000), is referred to for correction.
Appendix A: A/D conversion program
Appendix B: main program
Presently preferred embodiments of the present invention is described above.It is to be appreciated that the invention is not limited to above-mentioned
Particular implementation, devices and structures not described in detail herein should be understood as gives reality with the common mode in this field
It applies；Anyone skilled in the art, without departing from the scope of the technical proposal of the invention, all using the disclosure above
Methods and technical content many possible changes and modifications are made to technical solution of the present invention, or be revised as equivalent variations etc.
Embodiment is imitated, this is not affected the essence of the present invention.Therefore, anything that does not depart from the technical scheme of the invention, foundation
Technical spirit of the invention any simple modifications, equivalents, and modifications made to the above embodiment, still fall within the present invention
In the range of technical solution protection.
Claims (6)
1. the multi-path data acquiring system based on USB communication, which is characterized in that including data acquisition module, the data acquisition
Module includes A/D converter, voltage follower and microcontroller, after analog input signal is filtered by the voltage follower,
It is output to the A/D converter, the digital signal after A/D converter is converted is controlled core by USB by the microcontroller
Piece is exported to computer and is shown.
2. the multi-path data acquiring system as described in claim 1 based on USB communication, which is characterized in that the A/D converter
Using the TLC2543C that TI company produces, the serial A/D converter of 11 tunnel, 12 bit switch capacitor Approach by inchmeal.
3. the multi-path data acquiring system as claimed in claim 2 based on USB communication, which is characterized in that the voltage follow
Device is as made of 3 LM324 four high guaily unit circuits and several resistance and capacitor design.
4. the multi-path data acquiring system as claimed in claim 3 based on USB communication, which is characterized in that the microcontroller
8 8-digit microcontrollers manufactured using CMOS technology.
5. the multi-path data acquiring system as claimed in claim 4 based on USB communication, which is characterized in that the TLC2543's
Conversion end EOC, I/O clock, serial data input AD_DIN, serial data output terminal AD_OUT piece select CS to be separately connected
Pin P1.0, P1.1, P1.2, P1.3, P1.4 of the parallel bidirectional I/O mouth 1 of single-chip microcontroller.
6. the multi-path data acquiring system as claimed in claim 5 based on USB communication, which is characterized in that the TLC2543 institute
The 5V reference voltage source needed then passes through LM336 voltage-stabiliser tube and slide rheostat and 12V power supply is transformed into 5V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910052073.8A CN109902060A (en) | 2019-01-21 | 2019-01-21 | Multi-path data acquiring system based on USB communication |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910052073.8A CN109902060A (en) | 2019-01-21 | 2019-01-21 | Multi-path data acquiring system based on USB communication |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109902060A true CN109902060A (en) | 2019-06-18 |
Family
ID=66943942
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910052073.8A Pending CN109902060A (en) | 2019-01-21 | 2019-01-21 | Multi-path data acquiring system based on USB communication |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109902060A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113777990A (en) * | 2021-09-15 | 2021-12-10 | 广州安广电子科技股份有限公司 | Single-line debugging graphic terminal of single-chip microcomputer |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122785A (en) * | 2007-09-18 | 2008-02-13 | 韩杰 | Automatic measurement and control device and system |
| CN102680903A (en) * | 2012-05-11 | 2012-09-19 | 山东轻工业学院 | Portable storage battery state detection system and method |
| CN104199343A (en) * | 2014-08-15 | 2014-12-10 | 徐云鹏 | Micro data collection system based on serial storage mode |
-
2019
- 2019-01-21 CN CN201910052073.8A patent/CN109902060A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122785A (en) * | 2007-09-18 | 2008-02-13 | 韩杰 | Automatic measurement and control device and system |
| CN102680903A (en) * | 2012-05-11 | 2012-09-19 | 山东轻工业学院 | Portable storage battery state detection system and method |
| CN104199343A (en) * | 2014-08-15 | 2014-12-10 | 徐云鹏 | Micro data collection system based on serial storage mode |
Non-Patent Citations (5)
| Title |
|---|
| 刘泽西;程晶晶;孔力;: "基于USB2.0接口的高速实时数据采集系统", 测控技术, no. 02, 18 February 2007 (2007-02-18), pages 34 - 37 * |
| 唐伟;于平;李峥辉;: "STM32F103x的USB多路数据采集系统设计", 单片机与嵌入式系统应用, no. 08, 1 August 2009 (2009-08-01), pages 39 - 41 * |
| 钟秉翔 等: "《单片机应用技术与实践》", 30 September 2016, 重庆大学出版社, pages: 220 - 222 * |
| 韦禄民;: "一种工业级数据采集监控系统的设计与实现", 微计算机信息, no. 08, 15 March 2009 (2009-03-15), pages 134 - 135 * |
| 马飒飒: "《智能仪表设计开发与应用》", 30 June 2018, 西安电子科技大学出版社, pages: 37 - 39 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113777990A (en) * | 2021-09-15 | 2021-12-10 | 广州安广电子科技股份有限公司 | Single-line debugging graphic terminal of single-chip microcomputer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102136841B (en) | High-speed high-accuracy recorder and sampling data automatic-correction and high-order matching method thereof | |
| CN103617140B (en) | Electroneurographic signal compressed sensing processing verification system and construction method thereof | |
| CN108958638A (en) | Ultrahigh speed SAR data recorder and data record method | |
| CN101021551A (en) | Intelligent comprehensive electronic measuring instrument | |
| CN104614593A (en) | Self-calibration based high-precision intelligent instrument system and application method thereof | |
| CN207164980U (en) | A kind of telemetry terminal system of geological disaster data acquisition | |
| CN109342928A (en) | A kind of apparatus for testing chip and method | |
| CN201903917U (en) | High-speed high-accuracy recorder | |
| CN104237905A (en) | Big Dipper detector | |
| CN104597802B (en) | A kind of reproducible data collecting system of superelevation sample rate | |
| CN109902060A (en) | Multi-path data acquiring system based on USB communication | |
| CN102074055A (en) | Multi-machine collaboration framework based fast recorder and self-calibration and multi-machine collaboration method | |
| CN208861171U (en) | The circuit structure of synchronous acquisition protective device whole phasor | |
| CN110514912A (en) | A kind of secondary voltage kernel phase system | |
| Wang et al. | Design of PIC microcontroller-based high-capacity multi-channel data acquisition module | |
| CN201698207U (en) | Analog quantity collecting module based on FPGA (Field Programmable Gate Array) | |
| CN207440169U (en) | A kind of changeable fluid high-accuracy voltage sampling apparatus | |
| CN206515381U (en) | A kind of new Computer oscilloscope | |
| CN107727930A (en) | Intelligent high-precision analog signal sampling system and the method for sampling | |
| CN205484836U (en) | Multichannel pulse amplitude analyzer | |
| CN206161751U (en) | Follow -on electric energy quality detection device | |
| CN209590837U (en) | A kind of hand held high precision data collecting instrument | |
| CN206491791U (en) | A kind of temperature check circuit of Intelligent bracelet | |
| CN108197068A (en) | Embedded real-time data acquires and storage system and its method | |
| CN2725525Y (en) | Water level and water temperature automatic collecting device for downhole |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |