CN201655254U - Large-sized digital tube display circuit based on MAX7219 - Google Patents
Large-sized digital tube display circuit based on MAX7219 Download PDFInfo
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- CN201655254U CN201655254U CN2010201583086U CN201020158308U CN201655254U CN 201655254 U CN201655254 U CN 201655254U CN 2010201583086 U CN2010201583086 U CN 2010201583086U CN 201020158308 U CN201020158308 U CN 201020158308U CN 201655254 U CN201655254 U CN 201655254U
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- max7219
- microcontroller
- led charactron
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- electronic switch
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Abstract
The utility model discloses a large-sized digital tube display circuit based on MAX7219 and adopts the technical scheme that the circuit comprises a microcontroller, a MAX7219 display driving chip, a plurality of latch driving modules, a plurality of common anode LED digital tubes, a photosensor and a programmable control electronic switch, wherein the microcontroller is connected with the MAX7219 chip through three wires; the MAX7219 chip is connected with a plurality of latches and the corresponding common anode LED digital tubes to form a large-sized digital tube display driving circuit; and the photosensor and the electronic switch are connected with the microcontroller respectively through a wire to form an LED digital tube brightness control circuit. The circuit keeps the advantages of strong function and simple programming of the MAX7219 chip and realizes the static/dynamic display and brightness automatic control display of the large-sized and high-brightness LED digital tubes.
Description
Technical field
The utility model relates to a kind of display driver circuit of the LED of being used for charactron, relate in particular to a kind of large scale, high-brightness LED charactron quiet/dynamically show and brightness can change self-adjusting display driver circuit with environmental light intensity.
Background technology
In large scale LED charactron display circuit, often adopt the segment encode output line of 8 delivery outlets of microcontroller as the LED charactron, adopt the chip selection signal of other delivery outlet as the LED charactron, be equipped with and latch and driving circuit, finish the demonstration of LED charactron.It is many that this kind circuit takies the microcontroller resource, complex circuit.The MAX7219 chip of Maxim company is used for the dynamic scan display driver, and 8 * 8 static RAM (SRAM)s that can store display message are arranged in the chip, dynamic scan circuit, and the section, bit driver.It has only 3 string lines to link to each other with general purpose microprocessor, can drive 8 cloudy charactron or 64 light emitting diodes altogether at most.Adopt the MAX7219 chip to realize that LED is digital and show, advantage such as I/O interface, the chip functions that have the circuit compactness, can save CPU is powerful, programming is simple has obtained vast circuit designers and has approved.Yet the operating voltage of MAX7219 is 5V, and common cathode LED display driver only is applicable to that the small size LED charactron of the following driven of 3.5V shows, has limited its usable range.When the LED charactron was used for outdoor environment, because the influence of environmental light intensity, the LED charactron showed that contrast can great changes will take place, causes the LED charactron to show unclear (fine day) or dazzling (night).
The utility model content
At above-mentioned prior art, the utility model provides a kind of large scale charactron display circuit based on MAX7219, this circuit is on the basis of powerful, the programming advantage such as simple that has kept the MAX7219 chip, realize providing the static state of the driving of high voltage and electric current to show by latch and driver to the large scale charactron, and adjustable brightness.
In order to solve the problems of the technologies described above, the utility model based on the technical scheme that the large scale charactron display circuit of MAX7219 is achieved is: this circuit comprises microcontroller, MAX7219 display driver chip, a plurality of electronic switch that latchs driver module, a plurality of positive LED charactron altogether, light sensor and a control able to programme, is connected by 3 line conductors between described microcontroller and the MAX7219 display driver chip; Described MAX7219 display driver chip links to each other with a plurality of latchs, described MAX7219 display driver chip and each latch driver module all by 1 line conductor clock trigger signal, and described MAX7219 display driver chip and each latch driver module and carry out the segment encode data transmission by 8 parallel line conductors; Each latch driver module corresponding with 1 altogether positive LED charactron is connected, it connects the segment encode pin that is total to positive LED charactron by 8 line conductors between the two, the LED charactron is total to anode and connects driving power; Described light sensor is connected by 1 line conductor with microcontroller AD interface; The output terminal of described electronic switch is connected with the common oedoeagus of LED charactron and the positive pole of LED charactron supply voltage respectively; Be connected by 1 line conductor between the control end of described electronic switch and the microcontroller; Described controllable electronic switch is according to the instruction conducting of microcontroller or close, and by pwm signal of microcontroller output, by the break-make of PWM dutycycle control electronic switch, and then adjusts the brightness of LED charactron.
Compared with prior art, the beneficial effects of the utility model are:
The utility model circuit is on the basis of powerful, the programming advantage such as simple that has kept the MAX7219 chip, have only 4 lines to link to each other with general purpose microprocessor, realize that by latching driver module the high voltage of maximum 8 large scale LED charactrons and current drives show, and brightness can change adjustment automatically with environmental light intensity.Display mode is dynamic demonstration when showing digital the variation, is static the demonstration when number remains unchanged.
Description of drawings
Fig. 1 is the formation block diagram of the utility model based on the large scale charactron display circuit of MAX7219;
Fig. 2 is the schematic diagram of 8 digital display circuits of altogether positive LED of the utility model one embodiment.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is done to describe in further detail.
The utility model based on the formation block diagram of the large scale charactron display circuit of MAX7219 as shown in Figure 1, this comprises microcontroller, the MAX7219 display driver chip, a plurality of driver modules that latch, a plurality of positive LED charactrons altogether, a light sensor and a control electronic switch able to programme, be connected by 3 line conductors between described microcontroller and the MAX7219 chip, described MAX7219 chip links to each other with a plurality of driver modules that latch, described MAX7219 chip and each latch driver module and all provide clock trigger signal by 1 line conductor, and described MAX7219 chip and each latch driver module and carry out data transmission by 8 parallel line conductors; Each latchs the driver module correspondence and is connected with 1 positive LED charactron altogether, and it connects by 8 line conductors between the two; All are total to positive LED charactron and all are connected by 1 line conductor with described control electronic switch able to programme; Described light sensor is connected with microcontroller 1 road AD interface; Be connected by 1 line conductor between the control end of described electronic switch and the microcontroller; The other two ends of described electronic switch are connected with the common oedoeagus of all LED charactrons and the positive pole of LED charactron supply voltage respectively; Described controllable electronic switch is according to the instruction conducting of microcontroller or close; Display mode is dynamic demonstration when showing digital the variation, is static the demonstration when number remains unchanged.
Be the specific embodiment of the utility model below based on the large scale charactron display circuit of MAX7219.
Fig. 2 shows one 8 digital display circuits of altogether positive LED, and wherein 74LS273 latch and ULN2803 chip for driving formation latchs driver module.Described 333 pins DIG0～DIG7 bit code line connects 8 74LS273 latchs 11 (cp) pin respectively and latchs control end, is equivalent to chip selection signal, and these 8 bit data/address latch 74LS273 is a kind of 8D trigger of tape erasure function.The segment encode line SEGA～SEGG of described display driver chip MAX7219 pin and SEGDP are connected on the D0～D7 input end of 8 74LS273 triggers with the data bus form; When a certain position of DIG0～DIG7 chip selection signal was low level, data bus D0～D7's was corresponding segment encode data; When chip selection signal 11 (cp) pin has a rising edge, the 74LS273 trigger latchs the level state of input pin immediately, and is presented on output pin Q0～Q7 and latchs; DIG0～DIG7 sheet selects low level signal scan round, will send into corresponding flip/flops latch respectively by the data presented segment encode.
The ULN2803 chip for driving receives 74LS273 latch output signal, realizes the driving of 80011B (promptly being total to positive LED charactron) is shown.Hang the corresponding segment encode pin of positive charactron altogether on 8 open collector delivery outlets of ULN2803 chip for driving, positive charactron common pin connects positive source by electronic switch altogether.When 74LS273 latch output high level, the corresponding segment encode of ULN2803 driving LED charactron 80011B is bright, otherwise goes out.
Display driver chip MAX7219 realizes that the LED charactron dynamically shows under the effect of internal hardware dynamic scan display control circuit.Adopt the segment encode drive signal of each LED charactron of 74LS273 flip/flops latch in the utility model circuit, when showing digital change, the dynamically touring scanning of display driver chip MAX7219 display driver chip is finished video data and is upgraded.When showing digital the maintenance, can control display driver chip MAX7219 in dormant state by microprocessor, that is: working method not, at this moment, the LED charactron is static display mode, by the data of 74LS273 latches, is shown by ULN2803 chip for driving driving LED charactron.Circuit is realized display driver chip MAX7219 discontinuous operation, only under the situation that LED charactron video data changes, starts MAX7219 work, after finishing Data Update and latching, enters off position, to save power consumption.
Fig. 2 shows a described light sensor and is connected with microcontroller 1 road AD interface, light sensor is gathered environmental light intensity, compare with the luminous quantity of LED charactron,, realize that LED charactron display brightness can change adjustment automatically with environmental light intensity by adaptive algorithm.By pwm signal of microcontroller output,, and then adjust the brightness of LED charactron by the break-make of PWM dutycycle control electronic switch.
Shown in Fig. 2, LED charactron supply voltage is maximum permissible voltage (positive LED charactron 80011B is 12.5V altogether), adjusts LED charactron supply voltage by microprocessor output pulse width modulation signal PWM control PMOS pipe and can realize the brilliance control of LED charactron.Because LED charactron supply voltage is a maximum permissible voltage, has improved the safety coefficient of LED charactron work, it is reliable, convenient to adopt dutycycle to adjust the brightness of LED charactron.Cancel the current-limiting resistance of A～G field simultaneously, reduced power consumption.
The utility model has kept the use advantage of display driver chip MAX7219 based on the large scale charactron display circuit of MAX7219, realized large scale LED charactron quiet/dynamically show and brightness can change automatically with environmental light intensity and adjusts.In the practical application, latching driving circuit and can making circuit module and be inlaid on the LED charactron of every paths of LEDs charactron links to each other with display driver chip MAX7219 chip pin, and circuit is succinct, reliable.Prove that through experiment test this circuit performance is stable, have very high practical value.
Although in conjunction with figure the utility model is described above; but the utility model is not limited to adopt above-mentioned concrete chip () embodiment for example: 74LS273 latch and ULN2803 chip for driving; above-mentioned embodiment only is schematic; rather than it is restrictive; those of ordinary skill in the art is under enlightenment of the present utility model; under the situation that does not break away from the utility model aim, can also make a lot of distortion, these all belong within the protection of the present utility model.
Claims (1)
1. large scale charactron display circuit based on MAX7219, comprise microcontroller, MAX7219 display driver chip, a plurality of electronic switch that latchs driver module, a plurality of positive LED charactron altogether, light sensor and a control able to programme, it is characterized in that:
Be connected by 3 line conductors between described microcontroller and the MAX7219 display driver chip;
Described MAX7219 display driver chip links to each other with a plurality of latchs, described MAX7219 display driver chip and each latch driver module all by 1 line conductor clock trigger signal, and described MAX7219 display driver chip and each latch driver module and carry out the segment encode data transmission by 8 parallel line conductors;
Each latch driver module corresponding with 1 altogether positive LED charactron is connected, it connects the segment encode pin that is total to positive LED charactron by 8 line conductors between the two, the LED charactron is total to anode and connects driving power;
Described light sensor is connected by 1 line conductor with microcontroller AD interface; The output terminal of described electronic switch is connected with the common oedoeagus of LED charactron and the positive pole of LED charactron supply voltage respectively; Be connected by 1 line conductor between the control end of described electronic switch and the microcontroller; Described controllable electronic switch is according to the instruction conducting of microcontroller or close, and by pwm signal of microcontroller output, by the break-make of PWM dutycycle control electronic switch, and then adjusts the brightness of LED charactron.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010201583086U CN201655254U (en) | 2010-04-14 | 2010-04-14 | Large-sized digital tube display circuit based on MAX7219 |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010201583086U CN201655254U (en) | 2010-04-14 | 2010-04-14 | Large-sized digital tube display circuit based on MAX7219 |
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| CN201655254U true CN201655254U (en) | 2010-11-24 |
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| CN2010201583086U Expired - Fee Related CN201655254U (en) | 2010-04-14 | 2010-04-14 | Large-sized digital tube display circuit based on MAX7219 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106531062A (en) * | 2016-12-01 | 2017-03-22 | 成都凯天电子股份有限公司 | Display circuit device for dynamic-static driven scanning of multiple groups of LED nixie tubes |
| CN106782299A (en) * | 2017-01-23 | 2017-05-31 | 福建师范大学福清分校 | A kind of intelligent dimming LED screen |
| CN107270991A (en) * | 2017-02-24 | 2017-10-20 | 吉林省隆华测控股份有限公司 | A kind of water-level gauge Luminous scale |
| CN109754747A (en) * | 2017-11-01 | 2019-05-14 | 无锡华润矽科微电子有限公司 | Integrated LED drive circuit structure and corresponding LED display system |
| CN111445838A (en) * | 2018-12-27 | 2020-07-24 | 联咏科技股份有限公司 | Light source driving circuit and driving method |
-
2010
- 2010-04-14 CN CN2010201583086U patent/CN201655254U/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106531062A (en) * | 2016-12-01 | 2017-03-22 | 成都凯天电子股份有限公司 | Display circuit device for dynamic-static driven scanning of multiple groups of LED nixie tubes |
| CN106531062B (en) * | 2016-12-01 | 2019-12-27 | 成都凯天电子股份有限公司 | Display circuit device for dynamically and statically driving and scanning multiple groups of LED nixie tubes |
| CN106782299A (en) * | 2017-01-23 | 2017-05-31 | 福建师范大学福清分校 | A kind of intelligent dimming LED screen |
| CN106782299B (en) * | 2017-01-23 | 2019-04-09 | 福建师范大学福清分校 | A kind of intelligent dimming LED screen |
| CN107270991A (en) * | 2017-02-24 | 2017-10-20 | 吉林省隆华测控股份有限公司 | A kind of water-level gauge Luminous scale |
| CN109754747A (en) * | 2017-11-01 | 2019-05-14 | 无锡华润矽科微电子有限公司 | Integrated LED drive circuit structure and corresponding LED display system |
| CN109754747B (en) * | 2017-11-01 | 2023-09-19 | 华润微集成电路(无锡)有限公司 | Integrated LED driving circuit structure and corresponding LED display system |
| CN111445838A (en) * | 2018-12-27 | 2020-07-24 | 联咏科技股份有限公司 | Light source driving circuit and driving method |
| US11195458B2 (en) | 2018-12-27 | 2021-12-07 | Novatek Microelectronics Corp. | Circuit and method for driving light sources |
| CN111445838B (en) * | 2018-12-27 | 2022-04-29 | 联咏科技股份有限公司 | Light source driving circuit and driving method |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20101124 Termination date: 20130414 |