CN108508941A - A kind of temperature and humidity controller based on LPC1768 - Google Patents
A kind of temperature and humidity controller based on LPC1768 Download PDFInfo
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- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 26
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- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D27/00—Simultaneous control of variables covered by two or more of main groups G05D1/00 - G05D25/00
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Abstract
The invention discloses a kind of temperature and humidity controllers based on LPC1768 comprising collecting unit, control unit, input-output unit；Wherein, collecting unit：For acquiring the temperature and humidity in environment；Control unit：The real-time running state transmitted according to collecting unit, action command is sent out to input-output unit, it includes human-computer interaction display unit, LPC1768 controllers and communications interface unit, and the LPC1768 controllers are connect by communications interface unit with human-computer interaction display unit；Input-output unit：The work of manipulation executing agency is executed instruction according to control unit, input-output unit includes control relay, SSR and servo valve；Described control unit is connect by communications interface unit with collecting unit and input-output unit.Signal stabilization of the present invention, temperature and humidity acquisition precision is high, and output is stablized, and is swift in response, no interim card delay phenomenon, has higher Temperature and Humidity Control precision and preferable Control platform, and wide adaptability, at low cost.
Description
Technical field
The present invention relates to test and measuring technical field more particularly to a kind of temperature and humidity acquisition precision height, humiture models
Contain accurate system, output stabilization, the willing temperature and humidity controller based on LPC1768.
Background technology
In terms of the evolution of industrial temperature and humidity controller, it is broadly divided into three generations：First generation temperature and humidity controller is fixed
It is worth mode switching control, basic skills is to be previously set using the humidity and humidity in sensor detecting system when reaching
When temperature and humidity value, controller will disconnect mechanically and electrically air cock, and break-make control is carried out to heating source and humidifier.Currently,
This controller still has the value used in the occasion not high to some control accuracy requirements.Since this quasi-controller can not overcome
The hysteresis quality of humiture change procedure causes systematic parameter fluctuation larger, and control accuracy is low, is completely unsuitable for high-precision temperature
Humid control.Second generation temperature and humidity controller is the equipment controlled using PID modes, and development environment includes microcontroller, PLC or
Person's computer software these three.Using the humidity and humidity in high precision analogue conversion circuit acquisition system, by pid algorithm,
It is controlled to adjust, due to considering three error, error change and the accumulation of error factors of system in PID adjusting models, because
This, control performance is greatly superior to first generation control formula.But the quality of the quality of PID control, depend primarily on ratio
Three value, integrated value, differential value parameters are adjusted, as long as these three parameter tunings is correct, control accuracy is satisfactory
's.But its shortcoming is also just this, once when three parameter changes or controlled condition have greatly changed,
Its Control platform is just difficult to be guaranteed.In order to overcome this weakness of PID regulative modes, it has been proposed that a series of adjust automaticallies
The method of parameter, the i.e. self study of parameter, automatic setting method.It is this based on the temperature controller with adaptive pid algorithm development,
It is exactly current third generation temperature control instrument.
Controller used by constant temperature and moisture test machine is mostly based on second generation controller currently on the market, a small number of nominal
Its control effect of Self-tuning controller can not be fully up to expectations.Producer can excessively high publicize the performance indicator of oneself product, sometimes
Short run target or optimal index are only provided, or without just giving good uncertainty of measurement by long-term verification.More have
Notably, the controller of some producers can be by the way of increasing filter factor, the control result of display false.Existing control simultaneously
For device processed due to technology aging, update speed is slow, thinks little of man-machine interaction experience, it is difficult to it is various to meet client in actual production
Demand.
In aspect of performance, there is also certain differences for the relatively external temperature and humidity controller of country's temperature and humidity controller at present
Away from maximum difference is embodied in domestic temperature and humidity controller in full dose mainly or in terms of control algolithm between them
Temperature control precision is low in journey, and adaptivity is poor.It is this insufficient the reason is that caused by various aspects, be such as directed to different control
Object, since the deficiency of control algolithm causes control accuracy unstable.
For the above deficiency, a kind of novel temperature and humidity controller is needed at present, and to solve, control accuracy is low, adapts to
The shortcomings of property is poor, slow in reacting, man-machine interaction experience is poor, meets the market demand.
Invention content
In order to solve the problems in the prior art, the humiture control based on LPC1768 that the object of the present invention is to provide a kind of
Device processed, signal stabilization, temperature and humidity acquisition precision is high, scope control is accurate, and output is stablized, and is swift in response, no interim card
Delay phenomenon, better than certainly most of controller on sale on the market on user experience, have higher Temperature and Humidity Control precision and
Preferable Control platform.
To achieve the goals above, the technical solution adopted by the present invention is：
The present invention provides a kind of temperature and humidity controllers based on LPC1768 comprising collecting unit, control unit, input are defeated
Go out unit, wherein
Collecting unit：For acquiring the temperature and humidity in environment；
Control unit：The real-time running state transmitted according to collecting unit sends out action command to input-output unit；Its
Including human-computer interaction display unit, LPC1768 controllers and communications interface unit, the LPC1768 controllers are connect by communication
Mouth unit is connect with human-computer interaction display unit；
Input-output unit：The work of manipulation executing agency is executed instruction according to control unit；Input-output unit includes control
Relay, SSR and servo valve；
Described control unit is connect by communications interface unit with collecting unit and input-output unit.
Preferred scheme, the collecting unit include the warm and humid device of wet and dry bulb, A/D converter and the STM32 that sequentially connect micro-
Controller.
Further preferred scheme, the warm and humid device of wet and dry bulb include the first PT100 platinum resistance, the first analog circuit, the
Two PT100 platinum resistance, the second analog circuit and switching circuit；After the first PT100 platinum resistance is connect with the first analog circuit
It is connect with switching circuit, the 2nd PT100 platinum resistance is also connect with switching circuit after being connect with the second analog circuit；Described
The bulb of one PT100 platinum resistance is surrounded by gauze and gauze one end is immersed and is used as wet bulb in sink, for acquiring humidity；Described second
Naked be placed in air of PT100 platinum resistance is used as dry bulb, is used for collecting temperature.
Scheme still more preferably, the communications interface unit of described control unit include 232 interface all the way, and all the way 485
Interface, two-way CAN bus, all the way 232/485 changeable interface, all the way Ethernet interface.
Scheme still further preferably, the LPC1768 controllers are equipped with USBHOST interfaces and SD card interface.
The input-output unit further includes optical coupling isolator.
The servo valve is using L298 as driving chip.
Communications interface unit is isolated external signal and LPC1768 signals using isolating chip ADUM1201.
The LPC1768 controllers of described control unit automatically select corresponding pid algorithm and parameter using PID fuzzy controls
It is controlled.
Input-output unit controls chip using EPM240T100C5.
By using above technical scheme, the present invention is a kind of based on the temperature and humidity controller of LPC1768 and prior art phase
Than advantage is：
1, the present invention uses constant flow source measuring electric-resistivity method in terms of temperature and humidity acquisition, using 24 A/D conversion chips, and uses
Dedicated temperature collecting cell, make collecting unit independently of control unit flow except, vacateed a large amount of resource go acquisition temperature
Degree and moisture signal, to more accurate to the acquisition of the numerical value of temperature, humidity, to ensure to be controlled better effect.
2, since there are close coupling relationships, the variation of any physical quantity can all be made to another physical quantity between temperature and humidity
At great disturbance, and the present invention first decouples it during control, then by fuzzy PID algorithm, will control
Process is blurred, and then accurate actuating mechanism output quantity is obtained by pid algorithm, to obtain higher Temperature and Humidity Control
Precision and preferable Control platform.
3, by actual test, under a variety of different control conditions of the present invention, temperature range can be stablized at ± 0.1 DEG C,
Humidity range can be stablized ± 2%.System operation is steady, and stabilized speed is fast, reaches outstanding level in similar product.
4, starting up speed of the present invention is fast, it is only necessary to which one to two seconds time, system can complete initialization operation.It is man-machine
Phenomena such as interactive interface is swift in response, the delay of no interim card, better than certainly most of controller on sale on the market on user experience.
5, by actual test and utilization, the present invention can completely realize the function of having designed, and reach the effect in anticipation
Fruit：When acquiring multi way temperature and moisture signal simultaneously, signal stabilization, acquisition precision is high, wherein reachable ± 0.02 DEG C of temperature accuracy,
Humidity precision reachable ± 2%.
6, logic circuit processing capacity powerful CPLD has effectively been shared the insufficient pressure of LPC1768 interfaces, and has been made defeated
It is rapid to enter output module response, there is more stable output.
7, the present invention separately designs the collecting unit of system, control unit and input-output unit, enhances system
Scalability, it is user-friendly and installation.User can be according to the demand of oneself, and unrestricted choice collecting unit and input are defeated
Go out the combination of unit.To the wide adaptability of different type of machines, can fully meet the needs of different user.
8, the present invention has powerful autgmentability and commonality, other than the controller as constant temperature and moisture test machine, also
It can be used for quickly temperature to become, thermal shock, various types of environment chambers such as salt fog machine.In controller exploitation afterwards,
The development cycle for reducing new projects, reduce hardware cost and time cost.
Description of the drawings
Fig. 1 is a kind of structure diagram of the temperature and humidity controller based on LPC1768 of the present invention；
Fig. 2 is the connection figure of the LPC1768 controllers and communications interface unit of the present invention；
Fig. 3 is a kind of workflow schematic diagram of the temperature and humidity controller based on LPC1768 of the present invention；
Fig. 4 is ADUM1201 circuit diagrams；
Fig. 5 is B0505S circuit diagrams；
Fig. 6 is AT24C256 circuit diagrams；
Fig. 7 is W25Q256 circuit diagrams；
Fig. 8 is photoelectric coupled circuit figure；
Fig. 9 is driving circuit of servo valve.
Specific implementation mode
In order to make the objectives, technical solutions and advantages of the present invention clearer, with reference to specific example, to the present invention
It is further described.It should be understood that these descriptions are merely illustrative, and it is not intended to limit the scope of the present invention.In addition,
In illustrating below, descriptions of well-known structures and technologies are omitted, so as not to unnecessarily obscure the concept of the present invention.
Temperature and humidity controller, first will solve the problems, such as it is the acquisition about system humidity.Moisture measurement technology is come
By for a long time.Moisture measurement is one of problem famous in world's metering field always.One seems simple magnitude, has gone into seriously
Come, be related to considerably complicated physics-chemical theory analysis and calculate.With the development of electronic technology, modern age measuring technique also has
Development at full speed.Moisture measurement divides two from principle, as many as 30 kind.There are absolute humidity, phase to the representation method of humidity
To the ratio (weight or volume) etc. of humidity, dew point, moisture and dry gas.Common humidity measuring method has：Dynamic method (double pressures
Method, dual-temperature process, shunting), static method (saturated salt method, sulfuric acid process), dew point method, measurement with wet and panoramic electronic type pass
Sensor method.Here double platen presses, dual-temperature process are to be based on thermodynamics P, V, T equilibrium principle, and equilibration time is longer, and shunting is based on exhausted
Accurate mixing to moisture and absolute dry air.As a result of modern test and control means, these equipment can be made quite accurate,
But because of equipment complexity, expensive, running is time-consuming, is used mainly as standard metering, and the reachable ± 2%RH-of measurement accuracy ±
1.5%RH.Saturated salt method in static method is most common method in moisture measurement, simple and practicable.But saturated salt method is to liquid, gas
The balance requirement of two-phase is very tight, higher to the stability requirement of environment temperature.It uses requirement etc. to go to balance for a long time, low humidity point
It is required that longer.When humidity differences are larger in special humidity indoors and bottle, open be required for balance 6 ~ 8 hours every time.Dew point method
It is the temperature measured when humid air reaches saturation, is thermodynamic (al) direct result, accuracy is high, and measurement range is wide.Metering
Reachable ± 0.2 DEG C of precise dew-point hygrometer accuracy is even higher.But the chilled-mirror type dew point instrument with modern light-electricity principle is expensive,
Often matched with standard humidity generator.
For this controller using measurement with wet measuring moisture, this is the hygrometric method just invented in 18th century.It is with a long history, make
With most generally.Measurement with wet is a kind of indirect method, it converses humidity value with wet and dry bulb equation, and this equation is to have ready conditions
's：Wind speed i.e. near wet bulb must reach 2.5m/s or more.The environmental experiment case that our company is produced, passes through special fan
Control and air duct design, this can be easily reached and usually seem very exacting terms.Make wet and dry bulb measuring moisture
The accuracy of method reaches electronics humidity sensor, and will not as electronics humidity sensor with the extension of usage time,
Precision can significantly decrease.
A kind of temperature and humidity controller based on LPC1768 of the present invention comprising collecting unit, control unit and input and output
Unit, structure diagram as shown in Figure 1,
Collecting unit is connected by 485 interfaces with control unit, and due to the characteristic of 485 communication bus, control unit can be simultaneously
Acquire the data of the Temperature and Humidity module of multi pass acquisition unit.In some large-scale environmental test chambers such as walk-in type constant temperature and humidity machine, due to
Experimental box volume is larger, and circulated air has dead angle, experimental subjects to put unequal factor, leads in experimental box temperature and humidity simultaneously
Non- is substantially uniformity.Often there is client to propose to want the data of the Temperature and Humidity module in each corner inside measurement experiment case, so as to more complete
The experimentation that the observation measurand in face is subjected to.In the present solution, since collecting unit and control unit use separate type
Design, is attached so that the data of the Temperature and Humidity module that controller can measure almost limitless can be extended with 485 communication bus.
Control unit core is one piece of LPC1768 microcontroller.LPC1768 is the release of NXP companies based on ARM
A member in the microcontroller LPC17XX series of Cortex-M3 kernels.LPC17XX series Cortex-M3 microprocessors are used
In the highly integrated Embedded Application with low-power consumption of processing requirement.The operating frequency of LPC1700 Series of MCU is reachable
100MHz.ARM Cortex-M3 CPU have 3 level production lines and Harvard structure.The peripheral hardware of LPC17XX Series of MCU
Component include up to the flash memories of 512KB, the data storage of 64KB, ethernet mac, USB hosts/slave/
OTG interfaces, 8 channel DMA controllers, 4 UART, 2 channels CAN, 2 SSP controllers, SPI interfaces, 3
IIC interfaces, the IIS interfaces of 2 inputs and 2 outputs, 12 ADC in 8 channels, 10 DAC, motor control PWM, orthogonal volume
Code device interface, 4 general purpose timers, the general PWM of 6 outputs, with the battery-powered super low-power consumption RTC of independent electrical and up to
70 general I/O pins.Based on the powerful operational capabilities of LPC1768, abundant external interface and Resources on Chip, the present invention
Using LPC1768 as control axis.
Control unit provides abundant external interface, including 232 interface all the way, 1 tunnel, 485 interface, 2 tunnel CAN bus, and 1
Interface can be switched in road 232/485, all the way Ethernet interface, supports USBHOST functions, supports SD card storage.As shown in Fig. 2, being
The LPC1768 controllers of control unit and the connection diagram of communications interface unit, abundant interface can meet various types
The demand of constant temperature and moisture test machine, the selection that client can be supplied to abundanter.Communications interface unit is using complete isolated only
Vertical power supply power supply safe design, the isolation of external signal and cpu signal is carried out using isolating chip ADUM1201.ADUM1201 is
Based on ADI（Analog device, inc）The two-channel digital isolator of the iCoupler magnetic coupling isolation technologies of company, electricity
Road schematic diagram is as shown in Figure 4.The transformer technology for using high-speed cmos technique and chip-scale, it is each in performance, power consumption, volume etc.
The advantage that aspect has photoelectric isolating device incomparable.
ADUM1201 isolators provide two independent channel isolations in a device.Both sides operating voltage be 2.7V ~
5.5V supports low voltage operating and can realize level conversion.In addition, ADUM1201 has very low pulse-width distortion（<3ns）.With
Unlike the solution of other Phototube Couplings, ADUM1201 also has direct current calibration function, and there are one refresh circuits to ensure
Output state can also match with input state in the case of even if there be no input saltus step, this is for power-up state and with low
It is critically important under the input waveform of data rate or constant direct current input condition.
Communications interface unit is powered using independent DC power supply, uses DC-DC chips B0505S.B0505S circuit diagrams
As shown in figure 5, B0505S has small product size small, ripple is extremely low, and adaptive temperature is wide（Operating temperature range can by -40 DEG C to
85℃）, the advantages that Electro Magnetic Compatibility is good, sustainable short-circuit protection, good temp characteristic.B0505S can isolation voltage 3KVDC, use
The additional elements of Shi Wuxu, are designed using interior patches, meet international standard pin mode, meet ROHS requirements.
Control unit has abundant storage device.Wherein EEPROM uses preservation cores of the AT24C256 as frequently-used data
Piece, AT24C256 are the programmable read only memory of the serial electrically erasables of atmel corp 256kbit, circuit diagram such as Fig. 6
Shown, the double inline package of 8 pins has the characteristics that compact-sized, memory capacity is big, in 2 line buses and can connect 4
The IC, especially suitable for the data collecting system with high capacity data storage request.Erasable number is reachable repeatedly by AT24C256
It 1000,000 times, is very suitable for storing some data for needing frequently to read and wipe.
W25Q256 is mainly used for storing a large amount of experimental data, W25Q256 circuits as on piece mass storage device
Schematic diagram is as shown in Figure 7.W25Q256 is the memory solution that a minimum space, pin and power consumption are provided for system
Serial Flash memory.More more flexible than common serial Flash memory, performance is more superior.Based on it is double/tetra- times
SPI, they can immediately complete to provide data to RAM, including storage sound, text and data.The work that chip is supported
Voltage 2.7V to 3.6V, electric current is less than 5mA when normal work, and when power down is less than 1uA.All chips provide the encapsulation of standard.
W25Q256 can be completed by every page of 256 bytes, every page of 256 bytes with primary page programming instruction.Erasing page 16 every time（Fan
Area）, page 128（32KB blocks）, page 256（64KB blocks）It is wiped with full sheet.
W25Q80/16/32 supports standard serial peripheral interface（SPI）And double/tetra- times of outputs of high speed, it is double/tetra- times
Pin：Serial clock, chip select terminal, serial data I/O0 (DI), I/O1 (DO), I/O2 (WP) and I/O3 (HOLD).SPI is most
Height support 80MHz, when with read soon it is double/tetra- times instruction when, flank speed 160MHz when being equivalent to double output, four times output when
Flank speed 320MHz.This transmission rate is comparable to 8 and 16 parallel flash storages.
Input-output unit using EPM240T100C5, by altera corp developed in order to control by core, this chip, belongs to this
The CPLD products of company MAXII series.The MAX II trains that Altera is released are a revolutionary CPLD products.It
Based on breakthrough CPLD frameworks, single I/O pins least cost and minimum power consumption in all CPLD series of industry are provided.These
Device keeps its die size only same using new (LUT) system of tabling look-up using 0.18 μm of embedded Flash technique of TSMC
The 1/4 of process devices.MAX II series compares with previous generation MAX products, cost reduction half, power consumption only have its 1/10, together
When keep the original transient state startup of MAX series, single-chip, non-volatile and ease for use.New family device capacity has turned over twice,
Performance is previous generation MAX CPLD more than twice, and the designer of consumer, communication, industry and computer product is enable to use
MAX II family devices replace expensive and underaction small-sized ASIC and ASSP.EPM240T100C5 is the series entry level
Product, it is 192 to have 240 logic units, equivalent macroelement on chip, and resource is relatively abundanter, inside there is depositing for 8Kbit Flash
Space is stored up, controls input/output module repertoire enough.
Input-output unit uses optical coupling isolator, and external input is completely isolated with internal circuit, schematic diagram such as Fig. 8 institutes
Show.When there is control source in outside, the light emitting diode built in optocoupler is lit, and PN junction conducting, output end voltage is pulled to low
Level.When outside does not have control source, PN junction cut-off, output end exports high level.Optical coupling isolator carries instruction function, when
When having external voltage input, light emitting diode can be lit, and be used to refer to corresponding input terminal.
Servo valve is using L298 as driving chip, and driving circuit is as shown in figure 9, L298 is a single chip integrated height
Voltage, high current, the driving of two-way full-bridge type motor drive inductive load designed for connection standard TTL logic level（Such as
Relay, coil, DC and stepper motor）.L298 provides two enabled input terminals, can be independent of input signal the case where
Under, enabled or disabled L298 devices.The transmitter of L298 low level transistors connects together, and its corresponding outside port then may be used
For connecting an external inductive reactance.L298 also provides an additional control source, so its logic circuit can work
At lower voltages.L298 operating voltages are up to 46V, and total DC electric current reaches 4A, it is sufficient to meet the servo valve driving of disposable type
It uses.
Operation principle of the present invention is as shown in Figure 3：After booting, control unit will need region of memory to be used to reset, will be defeated
Enter the output relay Close All of output unit, SSR relay set.Initialization operation is carried out to servo valve, due to servo
Valve uses stepper drive principle, belongs to opened loop control, in the process of running, can not accurately control the aperture of servo valve.Therefore
It needs to be initialized when booting, when initialization, servo valve opening is first set as maximum, then closes servo valve,
Servo valve opening is finally set to 10% again, in order to avoid when compressor start, high-pressure side is obstructed, causes pressure excessive, damage compression
Machine.Communication interface is initialized, communications pins and baud rate are set.Initialize SD card and USB.
After completing to initialize, starts the cycle over and read temperature and humidity information.Temperature and humidity information is adopted by collecting unit
Collection, and obtained by way of the host query of control unit.Control unit sends out to collecting unit read warm and humid drag out a miserable existence first
It enables, collecting unit sends newest temperature and humidity value after receiving reading order, to control unit.Control unit is by the warm and humid of reception
Angle value is shown for controlling in the touch screen of human-computer interaction display unit.
In temperature and humidity control system, since temperature and humidity is a pair of physical quantity disturbed mutually, this gives common PID
Control brings great difficulty.The present invention uses PID fuzzy controls.
In the present invention, different according to temperature and humidity range, system is divided into high temperature, room temperature, low temperature, ultralow temperature,
And the states such as high humidity, normal wet, low humidity.According to state difference, PID fuzzy controls automatically select corresponding pid algorithm and parameter.
By pid algorithm, the precise control amount of actuating mechanism action is obtained.Actuating mechanism of the present invention is by heater, humidifier and compressor
Composition, control output quantity are also classified into heater aperture, and humidifier aperture is with three parts of machine servo valve opening.Wherein heater is dynamic
Make and humidifier action is by solid-state relay（SSR）To complete.The output quantity of compressor is completed by servo valve, passes through control
The aperture of servo valve, control compressor refrigerant enter the speed of experimental box, to realize to the accurate of cooling and wet down action
Control.
It is accurately controlled in order to obtain as a result, first having to obtain accurate temperature and humidity data.The number of temperature and humidity
It is completed according to by collecting unit.Wet and dry bulb measuring moisture device wherein is used for the acquisition of humidity.Wet and dry bulb measuring moisture device is with two
PT100 platinum resistance, wherein one in bulb with binding up with gauze in vain, the gauze other end is immersed in sink, i.e., is made by capillarity
Gauze often keeps moist, this i.e. wet bulb.Another unused gauze packet and be placed on the thermometer in air, the dry bulb of meaning（Dry bulb
Indicate the temperature of temperature）.The temperature acquisition of collecting unit is by 24 A/D conversion chip ADS1252, by collected wet and dry bulb
The dry bulb and wet bulb resistance value of measuring moisture device, the temperature value of dry bulb and wet bulb is obtained by look-up table；Simultaneously with following formula meter
Calculation obtains relative humidity:
Wherein U：Relative humidity %；etw：Saturation vapour pressure under wet-bulb temperature；et：Saturation vapour pressure under dry-bulb temperature；A：Often
Number； P：Atmospheric pressure；△t：Wet-bulb depression.
Human-computer interaction display unit selects the DGUS screens researched and developed by Beijing Di Wen companies as human-computer interaction interface.With tradition
LCM it is different by sequential or instruction control display, DGUS screens drive display mode, all displays and behaviour using Direct Variable
It is all based on the variable configuration file pre-set and carrys out work.It is developed using DGUS, user can be helped quick
Develop full graphics touch screen human-computer interface, the touch screen interactions such as touch screen input method, popup menu, sliding block dragging, increment adjusting
The variables such as mode and variable icon, characters in a fancy style, curve show, time variable show and can be easily accomplished by PC, it is possible to reduce work
The a large amount of programing works of Cheng Shi.
Communications interface unit is attached by serial ports and DGUS screens, when communications interface unit receives the life that DGUS screens are sent
After order, analysis deciphering can be carried out to order.Then different according to order, it is loaded into corresponding driver, completes page turning, is shown,
Deposit, the operations such as reading.
Communications interface unit includes 2 RS232 interfaces, 1 RS485 interface, 2 CAN bus, an Ethernet interface.
Wherein Ethernet interface uses TCP communication agreement, relative to UDP communication protocols, although Transmission Control Protocol in terms of efficiency of transmission, omits
It is inadequate, but in terms of the reliability of transmission, Transmission Control Protocol has prodigious advantage.
The above specific embodiments are only exemplary, is to preferably make skilled artisans appreciate that originally
Patent, be not to be construed as include to this patent range limitation；As long as appointing according to made by spirit disclosed in this patent
How with change or modification, the range that this patent includes is each fallen within.
Claims (10)
1. a kind of temperature and humidity controller based on LPC1768, which is characterized in that it include collecting unit, control unit, input it is defeated
Go out unit, wherein
Collecting unit：For acquiring the temperature and humidity in environment；
Control unit：The real-time running state transmitted according to collecting unit sends out action command to input-output unit；Its
Including human-computer interaction display unit, LPC1768 controllers and communications interface unit, the LPC1768 controllers are connect by communication
Mouth unit is connect with human-computer interaction display unit；
Input-output unit：The work of manipulation executing agency is executed instruction according to control unit；Input-output unit includes control
Relay, SSR and servo valve；
Described control unit is connect by communications interface unit with collecting unit and input-output unit.
2. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the acquisition is single
Member includes the warm and humid device of wet and dry bulb, A/D converter and the STM32 microcontroller sequentially connected.
3. a kind of temperature and humidity controller based on LPC1768 according to claim 2, which is characterized in that the wet and dry bulb
Warm and humid device includes the first PT100 platinum resistance, the first analog circuit, the 2nd PT100 platinum resistance, the second analog circuit and switch electricity
Road；The first PT100 platinum resistance is connect after being connect with the first analog circuit with switching circuit, the 2nd PT100 platinum resistance
It is also connect with switching circuit after being connect with the second analog circuit；The bulb of the first PT100 platinum resistance is surrounded by gauze and gauze
One end, which is immersed, is used as wet bulb in sink, for acquiring humidity；Naked be placed in air of the 2nd PT100 platinum resistance is used as dry bulb,
For collecting temperature.
4. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the control is single
The communications interface unit of member includes 232 interface all the way, all the way 485 interface, two-way CAN bus, 232/485 changeable is connect all the way
Mouthful, Ethernet interface all the way.
5. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the LPC1768
Controller is equipped with USBHOST interfaces and SD card interface.
6. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the input is defeated
It further includes optical coupling isolator to go out unit.
7. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the servo valve
Using L298 as driving chip.
8. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the communication connects
Mouth unit is isolated external signal and LPC1768 signals using isolating chip ADUM1201.
9. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the control is single
The LPC1768 controllers of member automatically select corresponding pid algorithm using PID fuzzy controls and parameter is controlled.
10. a kind of temperature and humidity controller based on LPC1768 according to claim 1, which is characterized in that the input is defeated
Go out unit and chip is controlled using EPM240T100C5.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114295120A (en) * | 2021-11-24 | 2022-04-08 | 华中光电技术研究所（中国船舶重工集团公司第七一七研究所） | Star sensor |
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