In recent years, with the rapid development of science and technology, the application of single-chip computer is constantly going deep, while driving the traditional control and detection to update with each passing day. In the application system of real-time detection and automatic control, single-chip computer is often used as a core component. The knowledge of single-chip computer is not enough. It should be perfected according to the specific hardware structure and the combination of software aiming at the characteristics of specific application objects. Firstly, this paper introduces the background, research significance and task function of this subject. Then, it briefly describes the demonstration of some main components and schemes used in the design process, and introduces the working principle of the system hardware. This design uses AT89S51 single chip computer to control neon lights. The system is composed of a single chip computer control part and a display part. The 128 light-emitting diodes in the display section are arranged in 8 rows and 16 columns in matrix form. The output signal of I/O port of MCU is amplified by triode to drive the diode to emit light. Different control signals make the LED display in different ways and patterns. The advent of neon light is based on the development of vacuum and gas discharge technology. Looking back on the development history of neon lights goes back to the Middle Ages. In 1643, Torricelli, an Italian physicist, first completed the first vacuum experiment in human history. After that, German physicist Garrick invented the vacuum in 1650, which became a reality and laid a foundation for the study of gas discharge in vacuum. In 1838, the real turning point of Faraday’s research on discharge in vacuum was the rise in the latter half of the 19th century.
In 1858, J. Prucker published a discussion on the fluorescence effect in vacuum tubes, and British scientists Krux and Hitov carried out systematic research on discharge in vacuum. During this period, in some early industrial revolutionary countries in Europe, the study of gas discharge phenomenon was very active, especially the applied research of the rich color of gas discharge, which is the historical background of the emergence of neon lights. At the end of the century, around 1893, neon lights, which were called “Moll” neon lights and “Geissler” neon models, were popular in some European cities. In the celebration of Queen Victoria’s 60th birthday, Gaisela neon lights were used as decorative lighting in the festive atmosphere. The original model neon lamp uses graphite as the electrode and fills nitrogen and carbon dioxide in a transparent glass tube with a diameter of 45 mm. The former gives off pink light, the latter gives off white light, bends into spirals or text patterns, and is also bright. Because of the active chemical properties of the filled gas, easy to react with the electrode, high sputtering rate of graphite electrode, a film was formed on the wall of the glass tube quickly, which absorbed the filled gas and reduced the pressure in the tube. Therefore, the life of this neon lamp is very short and has no practical value. Physicists and chemists in Britain and France have made outstanding contributions to the study of inert gases in order to find solutions to the extremely short lifetime of early neon lamps. In 1894, Professor Ramsey and Raleigh of University of London proved the existence of argon and obtained argon by fractionating air; in 1895, the chemical properties of helium were identified; in 1898, Professor Ramsay and M. Travers discovered neon in the air, and in the same year, krypton and radon were produced by liquid air fractionation. It was not until 1902 that Claude, thermostatic element a French scientist, invented the adiabatic expansion method for liquefying air and used it for the industrial separation of neon.
From then on, he pioneered the industrial extraction of inert gases. Using inert gas instead of active gas as filling gas of neon lamp not only extends the life of neon lamp greatly, but also enriches the color of neon lamp. This is a major technological breakthrough in the development process of neon lamp. The first appearance of neon lights in China was the neon advertisement of English “Royal Brand” typewriter displayed in the window of Evans Book Company, the busiest commercial street in Shanghai, on Nanjing East Road in 1926. In 1927, a Chinese-English neon sign was made and installed for Shanghai Central Hotel by Shanghai Far East Chemical Manufacturing Factory, the first neon light manufacturer in China. In 1930, the neon lamp power transformer was successfully made by ourselves; in 1945, the phosphor was made; in 1951, the inert gases such as argon and neon were trial-produced. From then on, the localization of all raw materials and devices for neon lamp was realized. The prosperity and development of neon lights are always associated with the prosperity and prosperity of the country. In the 1990s, a ten-mile neon street has been built on Nanjing Road in Shanghai; the city of Nanjing and Zhabei District in Shanghai are all implementing the night city plan; in order to improve the investment environment, Jinzhou Development Zone in Dalian has built a colorful city by holding the National Neon Light Grand Prix. Nowadays, large and small cities such as Tianjin, Chongqing and Shenzhou have built commercial and tourist cities with neon lights as the main decorative lighting. Basic Functions: Design a neon light controller to control 128 LBDs, which requires the formation of a variety of patterns or patterns. The Title requires the design of a neon light controller, which controls 128 lights, and forms a variety of patterns and patterns. In the design, the control part is completed by the single chip computer, and the LBD of the display part is driven by the output control signal of the single chip computer after amplification to form different patterns. Scheme 1: Extending I/O port by shift register. The input and output ports of 74HC595 MCU are extended to connect the light-emitting diodes to realize serial input and parallel output. The circuit diagram is shown in 1.1.1. This scheme can expand the number of controlled light-emitting diodes, but to control 128 LBDs, 16 shift registers are needed, many chips are needed, and PCB layout and wiring are inconvenient. Scheme 2: Matrix distribution is adopted. Using the P1 port of MCU as the row selection signal, the P2 and P0 ports as the column selection signal, 128 LBDs constitute 8 rows and 16 columns of matrix.
Detailed circuit diagram is shown in unit circuit design. This scheme can control each LBD individually, or each row or column separately. It can form rich patterns or patterns. The display part does not need extra chips. The circuit is simple, and the layout and wiring of PCB are easy and beautiful. In summary, considering that there are not too many LBDs to be controlled, and the matrix can form more abundant patterns, the layout and wiring of PCB board are also more beautiful, the second option is chosen. Scheme 1: Triode first stage drive. Driven by 1 9012, a row of 16 LBDs. The working current of each LBD is 10-15 mA and 16 x (10-15) is 160-240 mA, so a large current can be supplied by a triode. When a row is lit at the same time, it can meet the requirements of luminous work. When a light is on, it will not affect the work of LBD due to its very short duration. Scheme 2: Power amplifier chip. It can achieve good amplification and drive, stable performance and good effect, but the price is higher than the transistor, and the circuit is obviously more complex than the first scheme. In summary, the transistor drive circuit is simple, cost-effective, and can complete the driving role well. Choose the first option. The single chip computer controls the LBD of matrix arrangement to display in sequence. Seven display patterns or patterns are designed in the system, which are: (1) from inside to outside and from outside to inside in turn; (2) odd and even rows interleaving; (3) one row of axes scanning clockwise; (4) two middle rows of axes closing to both sides; (5) four different colors of lights interleaving; (6) single lights illuminating from the innermost circle outward in a spiral way; (7) Four adjacent rows and four relative rows are interlaced. The display part consists of 128 patch light-emitting diodes divided into eight rings, each consisting of 16 rings, which is equivalent to a matrix of 8 rows and 16 columns. These LEDs have four colors: red, yellow, blue and green. Each circle is arranged in the same color from inside to outside with green, red, yellow, blue, green, yellow, yellow, blue.
Each row of 16 LED’s anodes are connected together and eight output lines are connected to P1.0-P1.7 ports of MCU’s I/O port respectively; each row of 8 LED’s cathode is connected together and 16 output lines are connected to MCU’s P.0-P.7 and P.2.0-P.2.7 ports respectively. The control part is mainly completed by the minimal system of single chip computer. A single chip AT89S51, two 74HC373 latches, 12M crystal arrays and some corresponding resistors and sockets are adopted. Eight 9012 transistors in the drive part are also connected to this part. Eight output signals of P1 port are used as 8-line selective signals, and 16 output signals of P0 and P2 port are used as control signals to control 16 LEDs in each loop separately.
The output signal is amplified by 9012 to drive the light emitting diode.