Control card circuit of LED lattice screen
By designing an LED dot matrix screen control card circuit containing multiple circuits, the problems of high cost and large volume of control card in the prior art are solved, and the effect of reducing costs and volume is achieved, while improving user experience and promotion efficiency is improved. .
Patent Information
- Application Number
- CN202323382275.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-12
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2033-12-12
AI Technical Summary
The control card of existing LED dot matrix screens is high and large in size, resulting in high investment costs and cannot meet the needs of ordinary customers.
A control card circuit for LED dot matrix screen is designed, including power supply power supply, power supply voltage adjustment circuit, MCU main control circuit, communication circuit, information storage circuit, clock timing circuit and signal amplification circuit. Through the mutual cooperation of these circuits, MCU The main control circuit can control the LED dot matrix screen to display corresponding information based on the received information and the provided clock information.
On the basis of realizing the LED dot matrix screen display function, the volume of the control card is greatly reduced, production costs are reduced, user experience is improved, and the promotion of LED dot matrix screens is promoted, solving the high cost and The problem of large size.
Smart Images
Figure CN222507134U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of circuits, in particular to a control card circuit for an LED dot matrix screen. Background Art
[0002] LED dot matrix screen is composed of LED (light emitting diode), which displays text, pictures, animation, video, etc. by turning on and off the lamp beads. It is a modular display device with all parts and components, usually composed of display module, control system and power system. LED dot matrix display screen is simple to make and easy to install. It is widely used in various public places, such as bus station announcers, advertising screens, billboards, street lights, propaganda vehicles, subway stations and other public places, as well as private places such as shops, squares, stadiums and entertainment venues. It can also be used for indoor display in the home. Due to its unique advantages, it has received more and more attention. LED dot matrix display screen has the following advantages: high definition and brightness, can be clearly displayed under strong light; low power consumption, long life, low maintenance cost; support real-time content update, remote control through the network; can be used for outdoor energy-saving lighting to reduce power consumption.
[0003] However, LED dot matrix displays also have some disadvantages: high price, high investment cost, small viewing angle range, content can only be seen at a specific angle, the emission fan is noisy, sometimes it interferes with the surrounding environment, and cannot be used in a dark environment. It needs to be used in conjunction with the surrounding environment. Overall, LED dot matrix displays have a wide range of applications in advertising, information release, etc. With the development of technology and the reduction of costs, its cost performance is also constantly improving. I believe that in the future, LED dot matrix displays will become more popular and become an indispensable part of people's lives.
[0004] The LED dot matrix screens currently on the market generally have the problem of high control card costs and large size, which results in overkill and unnecessary expenses for general customers. Utility Model Content
[0005] In order to solve the problems in the prior art, the utility model provides a control card circuit for an LED dot matrix screen. By arranging a power supply, a power supply voltage adjustment circuit, an MCU main control circuit, a communication circuit, an information storage circuit, a clock timing circuit, a signal amplifying circuit and an LED dot matrix screen that cooperate with each other in the control card circuit of the LED dot matrix screen, the MCU main control circuit can control the LED dot matrix screen to display corresponding information through the signal amplifying circuit according to information received by the communication circuit, information provided by the information storage circuit and information provided by the clock timing circuit. On the basis of realizing the display function of the LED dot matrix screen, the volume of the control card can be greatly reduced, the production cost of the control card can be reduced, the user experience can be improved, the promotion of the LED dot matrix screen can be promoted, and the problems of high cost and large volume of the LED dot matrix screen in the prior art can be solved.
[0006] The utility model provides a control card circuit of an LED dot matrix screen, comprising a power supply, a power supply voltage adjustment circuit, an MCU main control circuit, a communication circuit, an information storage circuit, a clock timing circuit, a signal amplifying circuit and an LED dot matrix screen, wherein the output end of the power supply is connected to the input end of the power supply voltage adjustment circuit, the output end of the power supply voltage adjustment circuit is connected to the MCU main control circuit, the communication circuit, the information storage circuit, the clock timing circuit and the signal amplifying circuit for power supply, the input end of the MCU main control circuit is connected to the output end of the communication circuit, the output end of the information storage circuit and the output end of the clock timing circuit, the output end of the MCU main control circuit is connected to the input end of the information storage circuit and the input end of the signal amplifying circuit, the input end of the communication circuit is connected to the output end of a vehicle machine, the output end of the signal amplifying circuit is connected to the input end of the LED dot matrix screen, and the MCU main control circuit can control the LED dot matrix screen to display corresponding information through the signal amplifying circuit according to information received by the communication circuit, information provided by the information storage circuit and information provided by the clock timing circuit.
[0007] The utility model is further improved, the communication circuit includes an R232 communication circuit and an R485 communication circuit, the input end of the R232 communication circuit and the input end of the R485 communication circuit are communicatively connected to the output end of the vehicle computer, the output end of the R232 communication circuit and the output end of the R485 communication circuit are connected to the input end of the MCU main control circuit, and the MCU main control circuit is provided with a microprocessor U6, wherein the microprocessor U6 is provided with 48 pins, and the 9th, 24th, 36th, and 48th pins of the microprocessor U6 are connected to the power supply circuit. The output end of the voltage regulating circuit is connected, the 31st and 30th pins of the microprocessor U6 are connected to the output end of the R232 communication circuit, the 31st, 30th and 13th pins of the microprocessor U6 are connected to the output end of the R485 communication circuit, the 14th, 15th, 16th and 17th pins of the microprocessor U6 are connected to the information storage circuit, the 34th, 37th and 38th pins of the microprocessor U6 are connected to the output end of the clock timing circuit, and the 25th, 26th, 27th and 28th pins of the microprocessor U6 are connected to the input end of the signal amplifying circuit.
[0008] The utility model is further improved, the power supply voltage adjustment circuit is provided with a voltage adjustment chip U1 and a fuse resistor F1, wherein the voltage adjustment chip U1 is provided with 3 pins, the 3rd pin of the voltage adjustment chip U1 is connected to one end of the fuse resistor F1, the R232 communication circuit, the R485 communication circuit, and the signal amplification circuit, the other end of the fuse resistor F1 is connected to the output end of the power supply, the 2nd pin of the voltage adjustment chip U1 is connected to the 9th, 24th, 36th, and 48th pins of the information storage circuit, the clock timing circuit, and the microprocessor U6, and the 1st pin of the voltage adjustment chip U1 is grounded.
[0009] The utility model is further improved, the clock timing circuit is provided with a clock chip U9 and a bidirectional diode D33, wherein the clock chip U9 is provided with 8 pins, the first pin of the clock chip U9 is connected to the second pin of the voltage adjustment chip U1 through the bidirectional diode D33, and the fifth, sixth and seventh pins of the clock chip U9 are respectively connected to the 38th, 37th and 34th pins of the microprocessor U6.
[0010] The utility model is further improved, the information storage circuit is provided with a storage chip U2, wherein the storage chip U2 is provided with 8 pins, the 7th and 8th pins of the storage chip U2 are connected to the 2nd pin of the voltage adjustment chip U1, and the 1st, 2nd, 5th and 6th pins of the storage chip U2 are respectively connected to the 14th, 16th, 17th and 15th pins of the microprocessor U6.
[0011] The utility model is further improved, the R232 communication circuit is provided with an R232 chip U10 and a capacitor C12, wherein the R232 chip U10 is provided with 16 pins, the second pin of the R232 chip U10 is connected to the third pin of the voltage regulating chip U1 through the capacitor C12, the 16th pin of the R232 chip U10 is connected to the third pin of the voltage regulating chip U1, and the 9th and 10th pins of the R232 chip U10 are respectively connected to the 31st and 30th pins of the microprocessor U6.
[0012] The utility model is further improved, the R485 communication circuit is provided with an R485 chip U12, a resistor R177 and a resistor R175, wherein the R485 chip U12 is provided with 8 pins, the 3rd pin of the R485 chip U12 is connected to one end of the resistor R177, the other end of the resistor R177 is connected to the 3rd pin of the voltage regulating chip U1 through the resistor R175, the 8th pin of the R485 chip U12 is connected to the 3rd pin of the voltage regulating chip U1, and the 1st, 2nd and 4th pins of the R485 chip U12 are respectively connected to the 31st, 13th and 30th pins of the microprocessor U6.
[0013] The utility model is further improved, the signal amplifying circuit is provided with a signal amplifying chip U3, wherein the signal amplifying chip U3 is provided with 20 pins, the 4th, 5th, 6th and 7th pins of the signal amplifying chip U3 are respectively connected to the 28th, 27th, 26th and 25th pins of the microprocessor U6, and the 13th, 14th, 15th and 16th pins of the signal amplifying chip U3 are connected to the input end of the LED dot matrix screen.
[0014] The utility model is further improved, the model of the microprocessor U6 is STM32F100C8T6, the model of the voltage adjustment chip U1 is AMS1117-3.3, and the model of the signal amplification chip U3 is MW74HC245D.
[0015] The utility model is further improved, the model of the clock chip U9 is DS1302, the model of the storage chip U2 is W25Q32BVSSIG, the model of the R232 chip U10 is Sp_232, and the model of the R485 chip U12 is Sp_485.
[0016] Compared with the prior art, the beneficial effects of the utility model are as follows: a control card circuit for an LED dot matrix screen is provided, and by arranging a power supply, a power supply voltage adjustment circuit, an MCU main control circuit, a communication circuit, an information storage circuit, a clock timing circuit, a signal amplifying circuit and an LED dot matrix screen that cooperate with each other in the control card circuit of the LED dot matrix screen, the MCU main control circuit can control the LED dot matrix screen to display corresponding information through the signal amplifying circuit according to information received by the communication circuit, information provided by the information storage circuit and information provided by the clock timing circuit, and can greatly reduce the volume of the control card and reduce the production cost of the control card on the basis of realizing the display function of the LED dot matrix screen, thereby improving the user experience, promoting the promotion of the LED dot matrix screen, and solving the problems of high cost and large volume of the LED dot matrix screen in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0018] Figure 1 This is a principle block diagram of a control card circuit of an LED dot matrix screen of the utility model;
[0019] Figure 2 It is a circuit diagram of the MCU main control circuit of the utility model;
[0020] Figure 3 A circuit diagram of a power supply voltage adjustment circuit of the utility model;
[0021] Figure 4 A circuit diagram of a clock timing circuit of the utility model;
[0022] Figure 5 A circuit diagram of the information storage circuit of the utility model;
[0023] Figure 6 It is a circuit diagram of the R232 communication circuit of the utility model;
[0024] Figure 7 It is a circuit diagram of the R485 communication circuit of the utility model;
[0025] Figure 8 The figure is a circuit diagram of the signal amplifying circuit of the utility model. DETAILED DESCRIPTION
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present utility model; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model; the terms "including" and "having" and any variations thereof in the specification and claims of the present utility model and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present utility model or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order.
[0027] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0028] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings.
[0029] like Figure 1-8 As shown, the utility model provides a control card circuit of an LED dot matrix screen, including a power supply, a power supply voltage adjustment circuit, an MCU main control circuit, a communication circuit, an information storage circuit, a clock timing circuit, a signal amplifying circuit and an LED dot matrix screen, wherein the output end of the power supply is connected to the input end of the power supply voltage adjustment circuit, the output end of the power supply voltage adjustment circuit is connected to the MCU main control circuit, the communication circuit, the information storage circuit, the clock timing circuit and the signal amplifying circuit for power supply, the input end of the MCU main control circuit is connected to the output end of the communication circuit, the output end of the information storage circuit and the output end of the clock timing circuit, the output end of the MCU main control circuit is connected to the input end of the information storage circuit and the input end of the signal amplifying circuit, the input end of the communication circuit is connected to the output end of the vehicle computer, and the output end of the signal amplifying circuit is connected to the input end of the LED dot matrix screen. In this embodiment, the MCU main control circuit can control the LED dot matrix screen to display corresponding information through the signal amplification circuit according to the information received by the communication circuit, the information provided by the information storage circuit, and the information provided by the clock timing circuit. On the basis of realizing the display function of the LED dot matrix screen, it can greatly reduce the volume of the control card, reduce the production cost of the control card, improve the user experience, and promote the promotion of the LED dot matrix screen.
[0030] like Figure 1-2As shown, the communication circuit includes an R232 communication circuit and an R485 communication circuit. The input end of the R232 communication circuit and the input end of the R485 communication circuit are communicatively connected to the output end of the vehicle computer. The output end of the R232 communication circuit and the output end of the R485 communication circuit are connected to the input end of the MCU main control circuit. The MCU main control circuit is provided with a microprocessor U6, wherein the model of the microprocessor U6 is STM32F100C8T6, and the microprocessor U6 has 48 pins. The 9th, 24th, 36th, The 48th pin is connected to the output end of the power supply voltage adjustment circuit, the 31st and 30th pins of the microprocessor U6 are connected to the output end of the R232 communication circuit, the 31st, 30th and 13th pins of the microprocessor U6 are connected to the output end of the R485 communication circuit, the 14th, 15th, 16th and 17th pins of the microprocessor U6 are connected to the information storage circuit, the 34th, 37th and 38th pins of the microprocessor U6 are connected to the output end of the clock timing circuit, and the 25th, 26th, 27th and 28th pins of the microprocessor U6 are connected to the input end of the signal amplification circuit. In this embodiment, the communication circuit is used to receive the command information of the automobile computer, and the MCU main control circuit is used to control the LED dot matrix screen to display the corresponding information through the signal amplification circuit according to the information received by the communication circuit, the information provided by the information storage circuit, and the information provided by the clock timing circuit.
[0031] like Figure 3 As shown, the power supply voltage adjustment circuit is provided with a voltage adjustment chip U1 and a fuse resistor F1, wherein the model of the voltage adjustment chip U1 is AMS1117-3.3, and the voltage adjustment chip U1 is provided with 3 pins, the 3rd pin of the voltage adjustment chip U1 is connected to one end of the fuse resistor F1, the R232 communication circuit, the R485 communication circuit, and the signal amplification circuit, the other end of the fuse resistor F1 is connected to the output end of the power supply, the 2nd pin of the voltage adjustment chip U1 is connected to the information storage circuit, the clock timing circuit, and the 9th, 24th, 36th, and 48th pins of the microprocessor U6, and the 1st pin of the voltage adjustment chip U1 is grounded. In this embodiment, the power supply voltage adjustment circuit is used to supply power to the R232 communication circuit, the R485 communication circuit, the signal amplification circuit, the information storage circuit, the clock timing circuit, and the MCU main control circuit.
[0032] like Figure 4 As shown, the clock timing circuit is provided with a clock chip U9 and a bidirectional diode D33, wherein the model of the clock chip U9 is DS1302, and the clock chip U9 is provided with 8 pins, the first pin of the clock chip U9 is connected to the second pin of the voltage adjustment chip U1 through the bidirectional diode D33, and the fifth, sixth, and seventh pins of the clock chip U9 are connected to the 38th, 37th, and 34th pins of the microprocessor U6, respectively. In this embodiment, the clock timing circuit is used to record time and is called by the MCU main control circuit to output to the LED dot matrix screen.
[0033] like Figure 5 As shown, the information storage circuit is provided with a storage chip U2, wherein the model of the storage chip U2 is W25Q32BVSSIG, and the storage chip U2 is provided with 8 pins, the 7th and 8th pins of the storage chip U2 are connected to the 2nd pin of the voltage adjustment chip U1, and the 1st, 2nd, 5th, and 6th pins of the storage chip U2 are respectively connected to the 14th, 16th, 17th, and 15th pins of the microprocessor U6. In this embodiment, the information storage circuit is used to store information and also prevent information loss.
[0034] like Figure 6 As shown, the R232 communication circuit is provided with an R232 chip U10 and a capacitor C12, wherein the model of the R232 chip U10 is Sp_232, and the R232 chip U10 is provided with 16 pins, the second pin of the R232 chip U10 is connected to the third pin of the voltage regulating chip U1 through the capacitor C12, the 16th pin of the R232 chip U10 is connected to the third pin of the voltage regulating chip U1, and the 9th and 10th pins of the R232 chip U10 are respectively connected to the 31st and 30th pins of the microprocessor U6. In this embodiment, the R232 communication circuit is used to receive the command information of the automobile head unit and transmit it to the MCU main control circuit.
[0035] like Figure 7 As shown, the R485 communication circuit is provided with an R485 chip U12, a resistor R177 and a resistor R175, wherein the model of the R485 chip U12 is Sp_485, and the R485 chip U12 is provided with 8 pins, the 3rd pin of the R485 chip U12 is connected to one end of the resistor R177, the other end of the resistor R177 is connected to the 3rd pin of the voltage adjustment chip U1 through the resistor R175, the 8th pin of the R485 chip U12 is connected to the 3rd pin of the voltage adjustment chip U1, and the 1st, 2nd and 4th pins of the R485 chip U12 are respectively connected to the 31st, 13th and 30th pins of the microprocessor U6. In this embodiment, the R485 communication circuit is used to receive the command information of the automobile head unit and transmit it to the MCU main control circuit.
[0036] like Figure 8As shown, the signal amplification circuit is provided with a signal amplification chip U3, wherein the model of the signal amplification chip U3 is MW74HC245D, and the signal amplification chip U3 is provided with 20 pins, and the 4th, 5th, 6th, and 7th pins of the signal amplification chip U3 are respectively connected to the 28th, 27th, 26th, and 25th pins of the microprocessor U6, and the 13th, 14th, 15th, and 16th pins of the signal amplification chip U3 are connected to the input end of the LED dot matrix screen. In this embodiment, the signal, voltage, and current output by the MCU main control circuit cannot be used as the driving voltage and driving current of the LED dot matrix screen, because the voltage value and current are too small, which will cause signal distortion when driving the LED dot matrix screen, so a signal amplification circuit is needed to amplify the signal.
[0037] As can be seen from the above, the utility model provides a control card circuit for an LED dot matrix screen. By arranging a power supply, a power supply voltage adjustment circuit, an MCU main control circuit, a communication circuit, an information storage circuit, a clock timing circuit, a signal amplifying circuit and an LED dot matrix screen that cooperate with each other in the control card circuit of the LED dot matrix screen, the MCU main control circuit can control the LED dot matrix screen to display corresponding information through the signal amplifying circuit according to information received by the communication circuit, information provided by the information storage circuit and information provided by the clock timing circuit. On the basis of realizing the display function of the LED dot matrix screen, the volume of the control card can be greatly reduced, the production cost of the control card can be reduced, the user experience can be improved, the promotion of the LED dot matrix screen can be promoted, and the problems of high cost and large volume of the LED dot matrix screen in the prior art can be solved.
[0038] The specific implementation methods described above are preferred implementation methods of the present utility model, and are not intended to limit the specific implementation scope of the present utility model. The scope of the present utility model includes but is not limited to the specific implementation methods. All equivalent changes made in accordance with the present utility model are within the protection scope of the present utility model.
Claims
1. A control card circuit for an LED dot matrix screen, characterized in that: The invention comprises a power supply, a power supply voltage adjustment circuit, an MCU main control circuit, a communication circuit, an information storage circuit, a clock timing circuit, a signal amplifying circuit and an LED dot matrix screen, wherein the output end of the power supply is connected to the input end of the power supply voltage adjustment circuit, the output end of the power supply voltage adjustment circuit is connected to the MCU main control circuit, the communication circuit, the information storage circuit, the clock timing circuit and the signal amplifying circuit for power supply, the input end of the MCU main control circuit is connected to the output end of the communication circuit, the output end of the information storage circuit and the output end of the clock timing circuit, the output end of the MCU main control circuit is connected to the input end of the information storage circuit and the input end of the signal amplifying circuit, the input end of the communication circuit is connected to the output end of the vehicle computer, the output end of the signal amplifying circuit is connected to the input end of the LED dot matrix screen, and the MCU main control circuit can control the LED dot matrix screen to display corresponding information through the signal amplifying circuit according to the information received by the communication circuit, the information provided by the information storage circuit and the information provided by the clock timing circuit.
2. The control card circuit of the LED dot matrix screen according to claim 1, characterized in that: The communication circuit includes an R232 communication circuit and an R485 communication circuit. The input end of the R232 communication circuit and the input end of the R485 communication circuit are communicatively connected to the output end of the vehicle computer. The output end of the R232 communication circuit and the output end of the R485 communication circuit are connected to the input end of the MCU main control circuit. The MCU main control circuit is provided with a microprocessor U6, wherein the microprocessor U6 is provided with 48 pins, and the 9th, 24th, 36th, and 48th pins of the microprocessor U6 are connected to the The output end is connected, the 31st and 30th pins of the microprocessor U6 are connected to the output end of the R232 communication circuit, the 31st, 30th and 13th pins of the microprocessor U6 are connected to the output end of the R485 communication circuit, the 14th, 15th, 16th and 17th pins of the microprocessor U6 are connected to the information storage circuit, the 34th, 37th and 38th pins of the microprocessor U6 are connected to the output end of the clock timing circuit, and the 25th, 26th, 27th and 28th pins of the microprocessor U6 are connected to the input end of the signal amplification circuit.
3. The control card circuit of the LED dot matrix screen according to claim 2, characterized in that: The power supply voltage adjustment circuit is provided with a voltage adjustment chip U1 and a fuse resistor F1, wherein the voltage adjustment chip U1 is provided with 3 pins, the 3rd pin of the voltage adjustment chip U1 is connected to one end of the fuse resistor F1, the R232 communication circuit, the R485 communication circuit, and the signal amplification circuit, the other end of the fuse resistor F1 is connected to the output end of the power supply, the 2nd pin of the voltage adjustment chip U1 is connected to the 9th, 24th, 36th, and 48th pins of the information storage circuit, the clock timing circuit, and the microprocessor U6, and the 1st pin of the voltage adjustment chip U1 is grounded.
4. The control card circuit of the LED dot matrix screen according to claim 3 is characterized in that: The clock timing circuit is provided with a clock chip U9 and a bidirectional diode D33, wherein the clock chip U9 is provided with 8 pins, the first pin of the clock chip U9 is connected to the second pin of the voltage adjustment chip U1 through the bidirectional diode D33, and the fifth, sixth and seventh pins of the clock chip U9 are respectively connected to the 38th, 37th and 34th pins of the microprocessor U6.
5. The control card circuit of the LED dot matrix screen according to claim 4, characterized in that: The information storage circuit is provided with a storage chip U2, wherein the storage chip U2 is provided with 8 pins, the 7th and 8th pins of the storage chip U2 are connected to the 2nd pin of the voltage adjustment chip U1, and the 1st, 2nd, 5th and 6th pins of the storage chip U2 are respectively connected to the 14th, 16th, 17th and 15th pins of the microprocessor U6.
6. The control card circuit of the LED dot matrix screen according to claim 5, characterized in that: The R232 communication circuit is provided with an R232 chip U10 and a capacitor C12, wherein the R232 chip U10 is provided with 16 pins, the second pin of the R232 chip U10 is connected to the third pin of the voltage regulating chip U1 through the capacitor C12, the 16th pin of the R232 chip U10 is connected to the third pin of the voltage regulating chip U1, and the 9th and 10th pins of the R232 chip U10 are respectively connected to the 31st and 30th pins of the microprocessor U6.
7. The control card circuit of the LED dot matrix screen according to claim 6, characterized in that: The R485 communication circuit is provided with an R485 chip U12, a resistor R177 and a resistor R175, wherein the R485 chip U12 is provided with 8 pins, the 3rd pin of the R485 chip U12 is connected to one end of the resistor R177, the other end of the resistor R177 is connected to the 3rd pin of the voltage regulating chip U1 through the resistor R175, the 8th pin of the R485 chip U12 is connected to the 3rd pin of the voltage regulating chip U1, and the 1st, 2nd and 4th pins of the R485 chip U12 are respectively connected to the 31st, 13th and 30th pins of the microprocessor U6.
8. The control card circuit of the LED dot matrix screen according to claim 7, characterized in that: The signal amplifying circuit is provided with a signal amplifying chip U3, wherein the signal amplifying chip U3 is provided with 20 pins, the 4th, 5th, 6th and 7th pins of the signal amplifying chip U3 are respectively connected to the 28th, 27th, 26th and 25th pins of the microprocessor U6, and the 13th, 14th, 15th and 16th pins of the signal amplifying chip U3 are connected to the input end of the LED dot matrix screen.
9. The control card circuit of the LED dot matrix screen according to claim 8, characterized in that: The model of the microprocessor U6 is STM32F100C8T6, the model of the voltage adjustment chip U1 is AMS1117-3.3, and the model of the signal amplification chip U3 is MW74HC245D.
10. The control card circuit of the LED dot matrix screen according to claim 9, characterized in that: The model of the clock chip U9 is DS1302, the model of the storage chip U2 is W25Q32BVSSIG, the model of the R232 chip U10 is Sp_232, and the model of the R485 chip U12 is Sp_485.