CN1750069A - Persistence of vision display system and method for realizing display thereof - Google Patents

Abstract

The display system for persistence of vision includes PC, mobile control platform and display screen device. The display method includes converting the text or graph to be displayed into digital signal in the PC; transmitting the digital signal in wired or wireless mode to the display screen device and controlling the LEDs' on-off state with the monolithic computer in the display screen device; and driving the LED line to rotate or oscillate with the driving mechanism so as to form annular or planar display screen smartly by means of the vision persistence of human eyes. The present invention has the features of simple structure, unique visual angle, novel design, convenient use, etc. and has display content changeable at will.

Description

Persistence of vision display system and method for realizing display thereof

technical field

The invention relates to an electronic display screen, in particular to a display screen which utilizes the persistence of vision effect of human eyes to generate continuous images for discontinuous light.

Background technique

As a new type of display material, LED dot matrix has developed rapidly in recent years and has a good market prospect. Among them, LED large-screen displays are widely used in fields such as industry, transportation, commercial advertisements, press releases, sports competitions, and electronic scene simulation. However, the existing LED large screen requires a large number of LEDs and driver chips, and the control is complicated, which makes the display screen expensive and difficult to operate.

The Chinese utility model patent No. 03257185.2 discloses a "multi-layer array light source mobile imaging display device", which is characterized in that an electronic control circuit is installed on a displaceable support, and is set in the normal direction of the movement direction of the displaceable support Several light-emitting arrays in different positions, the several light-emitting arrays can be in the shape of straight bars or various geometric curves, and they can be displaced on a set plane or curved surface through a moving device. During the movement, the point light sources of the light-emitting array are under the control of the electronic circuit, and are lit or extinguished according to the predetermined program. Due to the persistence of vision of the human eye, the observer can see the multi-layer nesting with different shapes or the depth and thickness of the three-dimensional light source. Graphic information. This kind of display device is in a fixed cycle, and the displayed content cannot be changed in real time as required.

Contents of the invention

The object of the present invention is to provide a visual persistence display system and a display method thereof, which can change the displayed content at any time as required.

In order to achieve the above object, the persistence of vision display system of the present invention includes a PC, a mobile control platform and a display screen;

In the PC, there is software for taking modulus and digitizing the content to be displayed, and the serial port of the PC carries out data transmission with the mobile console or the display screen;

The mobile control platform includes a serial port transceiver circuit connected to the PC, a single-chip microcomputer control circuit connected to the serial port transceiver circuit and a liquid crystal display, control keys, wireless transmission module, RAM and EEPROM connected to the single-chip microcomputer control circuit respectively;

The display screen part includes a wireless receiving module, a single-chip control circuit connected to the wireless receiving module, EEPROMs respectively connected to the single-chip control circuit, multiple LEDs arranged in a row, and a driving mechanism for driving the row of LEDs to rotate or swing.

The single-chip microcomputer in the mobile control platform is preferably AT89C55.

The single-chip microcomputer in the said display part is preferably AT89S52.

The LEDs arranged in a row have 64 or 32 bits.

In order to simplify the operation of the control platform, there are four control keys in the mobile control platform, which are respectively connected to four I/O ports of the corresponding single-chip microcomputer.

The display method of the persistence of vision display system of the present invention may be based on wired data transmission or wireless data transmission.

The methods based on wireless data transmission are:

Convert the text or graphics to be displayed into digital signals in the PC;

The digital signal is transmitted to the serial port transceiver circuit of the mobile control platform through the serial interface, then transmitted to the single-chip microcomputer control circuit of the mobile control platform by the serial port transceiver circuit, and then sent to the wireless receiving module of the display screen through the wireless transmission module;

The wireless receiving module transmits the received digital signal to the single-chip microcomputer control circuit of the display part, and the single-chip microcomputer control circuit controls the on-off state of each LED;

The driving mechanism drives the whole row of LEDs to rotate or swing.

The methods based on wire data transmission are:

Convert the text or graphics to be displayed into digital signals in the PC;

The digital signal is directly transmitted to the single-chip microcomputer control circuit of the display part through the serial interface, and the single-chip microcomputer control circuit controls the on-off state of each LED;

The driving mechanism drives the whole row of LEDs to rotate or swing.

In the PC, the English and numeric characters to be displayed are decomposed into 16×32 dot matrix, the Chinese characters to be displayed are decomposed into 32×32 dot matrix, and the graphics to be displayed are decomposed into 64×64 dot matrix Mode.

The display system of the present invention and the method for realizing display thereof skillfully utilize the persistent visual characteristics of the human eye to form a circular or flat display screen, and use a row of multiple LEDs to achieve the same display effect as a large-scale LED screen, greatly The number of LEDs and driver chips is reduced, and the cost is effectively controlled. High-speed wireless data transmission makes the display screen and PC input system not subject to space constraints, which is convenient for the installation and use of the display screen; the display content can be switched in real time through the mobile control platform, and the display effect can be changed; Or figure acquisition, and handwriting input to display the content, the system can realize the display of arbitrary graphics. The invention has the characteristics of simple structure, unique viewing angle, novel design, convenient use and the like.

Description of drawings

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a hardware block diagram of the present invention.

Figure 2 is a block diagram of the main circuit of the display screen.

Figure 3 is the main program flow for converting the content to be displayed into a digital signal in a PC.

Fig. 4 is a flow chart of the character taking model program.

Figure 5 is a flow chart of the graphics and model subroutine.

Fig. 6 is a block diagram of the main program of the mobile control platform.

Fig. 7 is a flow chart of the serial interrupt subroutine of the mobile control platform.

Figure 8 is a flow chart of the wireless sending subroutine.

Fig. 9 is a flow chart of the main program of the display screen.

Figure 10 is a flow chart of the wireless receiving subroutine.

Detailed ways

Embodiment one:

As shown in Figure 1, the hardware includes three parts: PC, mobile control platform and display screen. Convert the content to be displayed into a digital signal in the PC. The mobile control platform is mainly responsible for receiving the touch data from the PC-side software, adding control characters and saving them. At the same time, the mobile control platform can also send specific control commands to the display screen to switch the display content and change the display effect. The display part is mainly to control the speed of the motor and the single-chip microcomputer to control the LED to display text, graphics or animation.

The mobile control platform is mainly responsible for receiving the digital signals transmitted from the PC, adding control instructions and saving them. The unique design ensures that the data will not be lost due to power failure. When it needs to be displayed, the data can be called out and wirelessly transmitted to the display screen, so as to realize the timely update of the displayed content. At the same time, the mobile control platform can send specific control commands to the display screen to switch the display content and change the display effect.

The mobile control platform is composed of the following parts:

1. MCU AT89C55. The controller adopts AT89C55, which is a low-power, high-performance CMOS microcontroller. The system adopts the menu function and has a large amount of memory, so the MCU AT89C55 with relatively large Flash Memory is selected.

2. Serial transceiver circuit. The serial transceiver circuit is composed of the mature serial transceiver chip MAX232.

3. Wireless sending module. This system adopts RFW102 chipset. RFW102 chipset is a half-duplex DSSS wireless transceiver dual-purpose IC, which uses ASK modulation mode, and the working frequency is 2.4GHz. The chipset is a short-range wireless transceiver IC consisting of three chips with a simple all-digital serial I/O interface. Its typical output power is 2dBm, the highest transmission rate is 1Mb/s, and the transmission distance of RFW102 is relatively long (20 meters indoors, 80 to 100 meters outdoors). The chipset includes an antenna printed on the printed circuit board, so it is very convenient to use.

4. Keyboard. The control key consists of four keys, which are "OK", "Exit", "Left Shift" and "Right Shift". Due to the small number of keys, they are directly connected to the four I/O ports.

5. LCD screen. What this liquid crystal screen chooses is the liquid crystal of 128*64. The 128×64 liquid crystal display module is a 128×64 dot matrix liquid crystal display module, which can display various characters and graphics, and can directly interface with the CPU. It has 8-bit standard data bus, 6 control lines and power lines. Using KS0107 control IC. Single-chip microcomputer programming adopts the menu display mode, and the corresponding function can be selected through the function keys of the keyboard. Makes the mobile control platform easy to use. The LCD module can display the working status of the whole system in real time. When the mobile control platform sends data to the display screen, the LCD can also display the content of the transmitted data accordingly.

Keypad and LCD display form a powerful remote control menu. By controlling the four keys of "Exit", "OK", "Left Shift" and "Right Shift", powerful kinetic energy such as receiving data from the PC, saving data, and sending data wirelessly is realized. Through the mobile control platform, you can also choose the display mode of fixed screen and scrolling screen. The mobile control platform is made into the size of a home appliance remote control.

The display part is composed of the following parts:

1. Wireless receiving module. Using RFW102 chipset.

2. Driving mechanism. The drive mechanism consists of an adjustable-speed DC motor, a DC governor and brushes.

Adjustable speed DC motor. The DC motor selected in the present invention is a speed-adjustable DC motor produced by Panasonic Corporation, its rated operating voltage is 220V, and its adjustable speed range is 0-6000r/min. The method of speed regulation can be seen from the mechanical characteristic equation of the motor:

$\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; u</span>}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}\mathrm{<span\; class="notranslate">\; \&Phi;</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; \&Phi;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}\mathrm{<span\; class="notranslate">\; m</span>}$

In the above formula, when the torque M is constant (that is, the load is constant), there are three factors that affect the motor rotation speed: the power supply voltage U, the armature resistance r _a and the main magnetic flux Φ. As long as one of them is changed, the motor's The speed can be adjusted. The speed regulation system of this system adopts the speed regulation method of changing the terminal voltage. Changing the terminal voltage U of the armature can correspondingly increase or decrease the number of rotations of the DC motor. This method of speed regulation is simple in principle, easy to implement, and good in stability.

DC governor. The selected DC governor has a rated voltage of 220V, a rated current of 8A, and an adjustable output DC voltage of 0-110V. Its working principle is to adjust the output voltage by adjusting the thyristor.

brushes. The brushes are self-designed by referring to the power supply brushes inside the motor. The power supply effect is satisfactory.

3. Column dot matrix composed of 64 ultra-high brightness LEDs. When displaying, the English characters adopt the 16×32 dot matrix method, the Chinese characters adopt the 32×32 dot matrix method, and the graphics adopt the 64×64 dot matrix method, and the dynamic display function can also be realized at the same time.

4. Single-chip microcomputer control circuit. As shown in Figure 2, the single-chip control circuit is mainly composed of a single-chip microcomputer AT89S52, EEPROM 28C256, several latches 373 and a wireless receiving circuit module. After receiving the data, the single-chip microcomputer stores useful data in EEPROM, so that the data will not be lost after power failure. In addition, 8 373s are expanded on the bus of the single-chip microcomputer, and each 373 controls 8 LED lights, so the single-chip microcomputer can flexibly control the on-off status of 64 LEDs.

The software part of the present invention is introduced as follows:

The software of the PC is programmed with VB, and its main function is to convert the content to be displayed into a digital signal on the PC in real time and send the data. English or numbers are decomposed into 16×32 dot matrix, Chinese characters are 32×32 dot matrix, and graphics are 64×64 dot matrix. The self-developed application software can directly take fonts and send data, has a friendly interface and is easy to operate, and can be used without any professional knowledge.

The software in the PC of the present invention adopts the real-time mode to take the model:

Data→Graph→Data.

By introducing the intermediate quantity of graphics, the extraction of fonts becomes flexible, and instant conversion can be realized regardless of any fonts and symbols. The process is shown in Figures 3, 4, and 5.

Character mode modulo process, see Figure 4:

When the character mode is selected, the graphics function is set to a locked state, leaving only the main button of the graphics function in an active state. At this time, only a text box appears on the interface, waiting for the user to enter text.

When the user clicks the text box, the content of the text box is set to empty, and the text box will not be cleared after clicking the text box. A picture frame is set in the background to be hidden forever, and it is only operated as an intermediate variable, which has no effect on the user. After the input is completed, the user presses the button to take the model, and the program first judges whether the entry is a font or a graphic.

Automatically jump into the character font segment code when it is determined as font mode.

Map the fetched individual characters to a picture box. To judge whether the current character is a Chinese character or a non-Chinese character, a 32×32 point modulus is used for the Chinese character modulus, and a 16×32 modulo is used for the non-Chinese character.

The modulus part adopts the intersection point modulus. After the characters are mapped to the picture frame, the color of the intersection point is judged, black is judged as 0, and white is judged as 1. And output the modulo data to the output text box.

When the button to send fonts is pressed, the content of the output text box is first sent to the sending buffer of COM, and the COM port directly sends the data to the EEPROM of the mobile control platform microcontroller for storage when it is confirmed that it can be sent.

When the "Reset All" button is pressed, the text input box is cleared, the number of clicks is set to 0 and the words waiting for input are displayed in the input text box, and all arrays are set to 0 at the same time, and the sending buffer of COM is cleared.

The character continuation function is designed for the lack of accuracy of the 32×32 dot matrix, and some points cannot be displayed when taking Song typeface characters. This function exists as an extended mode of the character mode. When this function is turned on, the color selection is not only 32 ×32 intersection points, but each intersection point and a point in a small range centered on the intersection point are selected for color. Once the color of a certain point in the range is judged to be black, the Boolean value at the intersection point is set to 0. The bold font is the default font, and this function does not need to be turned on.

The modulo taking process in graphic mode, see Figure 5:

1) When the graphic mode is selected, the character modulo function is set to locked, leaving only the main button of the character function active, and only the graphic box appears on the interface, and the user can draw or load images.

2) When the user's mouse falls on the drawing frame and the drawing button is pressed, the brush is set to black and enters the drawing state, where any graphics can be drawn; when the user's mouse falls on the drawing frame and the erase button is pressed, The brush is set to white and enters the erasing state, which can erase the graphics on the drawing frame.

3) After the input is completed, the user presses the button to take the model, and the program first judges whether the entry is a character model or a graphic.

4) Automatically jump into the graphic font segment code when it is determined as the graphic mode.

5) The modulo taking part adopts the intersection point modulus. After the graphic is mapped to the picture frame, the color of the intersection point is judged, black is judged as 0, and white is judged as 1. And output the modulo data to the output text box.

The obtained modulo data is transmitted to the single-chip microcomputer of the mobile control platform through the serial port transceiver circuit.

In the single-chip microcomputer of the mobile control platform, after the program is powered on and initialized, it is in a waiting state. Serial interrupts have the highest interrupt priority. So no matter what the microcontroller is processing, when the serial port interrupt comes, it will give priority to the serial port interrupt. Sending wireless data is controlled by buttons and menus. Send wireless data is performed by menu selection. The main program flow charts are shown in Figure 6, Figure 7, Figure 8, and Figure 9.

The on and off of the LED and the reception of wireless data are controlled by the single chip microcomputer. After the data is received by the wireless module, it is transmitted to the microcontroller through the serial interface of the microcontroller. When wireless data arrives, the received data will be processed first. Figure 10.

The present invention can clearly display dot-matrix characters, graphics and dynamic pictures by cleverly using the persistence of human vision, and has the characteristics of simple structure, unique viewing angle, novel design, and convenient use. It can be widely used in commercial advertisements, meeting notices, slogans, environmental decoration, and demonstration experiments of persistence of vision in advanced physics teaching, etc., and has high social application value.

Embodiment two:

Using the display system of the present invention, when the distance between the PC and the display screen is relatively short, the mobile control platform may not be selected as the hardware, and the data transmission between the PC and the display screen is realized by wire. In this embodiment, the serial port of the PC is connected to the single-chip microcomputer control circuit of the display screen by wire, and the display screen receives data from the PC by wire, and the display content or display mode can be changed on the screen by operating in the PC . All the other are the same as embodiment one.

Claims (8)

1. A visual persistence display system, including a PC, a mobile control platform and a display screen; In the PC, there is software for taking modulus and digitizing the content to be displayed, and the serial port of the PC carries out data transmission with the mobile console or the display screen; The mobile control platform includes a serial port transceiver circuit connected to the PC, a single-chip microcomputer control circuit connected to the serial port transceiver circuit and a liquid crystal display, control keys, wireless transmission module, RAM and EEPROM connected to the single-chip microcomputer control circuit respectively; The display screen part includes a wireless receiving module, a single-chip control circuit connected to the wireless receiving module, EEPROMs respectively connected to the single-chip control circuit, multiple LEDs arranged in a row, and a driving mechanism for driving the row of LEDs to rotate or swing. 2. The display system according to claim 1, characterized in that: the single-chip microcomputer in the mobile control platform adopts AT89C55. 3. The display system according to claim 1, characterized in that: the single-chip microcomputer in the display screen part adopts AT89S52. 4. The display system according to claim 1, wherein the LEDs arranged in a row have 64 or 32 bits. 5. The display system according to claim 2, characterized in that there are four control keys in the mobile control platform, which are respectively connected to four I/O ports of the corresponding single-chip microcomputer. 6. A method for displaying by a display system according to claim 1, characterized in that: Convert the text or graphics to be displayed into digital signals in the PC; The digital signal is transmitted to the serial port transceiver circuit of the mobile control platform through the serial interface, then transmitted to the single-chip microcomputer control circuit of the mobile control platform by the serial port transceiver circuit, and then sent to the wireless receiving module of the display screen through the wireless transmission module; The wireless receiving module transmits the received digital signal to the single-chip microcomputer control circuit of the display part, and the single-chip microcomputer control circuit controls the on-off state of each LED; The driving mechanism drives the whole row of LEDs to rotate or swing. 7. A method for displaying by a display system according to claim 1, characterized in that: Convert the text or graphics to be displayed into digital signals in the PC; The digital signal is directly transmitted to the single-chip microcomputer control circuit of the display part through the serial interface, and the single-chip microcomputer control circuit controls the on-off state of each LED; The driving mechanism drives the whole row of LEDs to rotate or swing. 8. The method according to claim 6 or 7, characterized in that: in the PC, the English and numeric characters to be displayed are decomposed into 16×32 dot matrix, and the Chinese characters to be displayed are decomposed into 32× 32 dot matrix, decompose the graphics to be displayed into 64×64 dot matrix.

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