Design of large LED display system based on FPGA+MCU

led2015

Design of large LED display system based on FPGA+MCU [Copy link]

The traditional large-scale LED display system uses MCU, ARM or PLD as the core control chip. The LED display control system with FPGA as the core is relatively complex to design and implement, and needs to be based on high-performance FPGA chips. The LED display control system with microprocessor as the core is not flexible enough. When changing the display size of the LED screen, the system design needs to be greatly modified. Although PLD has greatly improved the processing speed and can well control multi-module display, it is obviously inferior to FPGA in timing circuit description. A design scheme of a large-scale LED display system based on FPGA and MCU is proposed. In this system, FPGA is the main control unit and MCU is the scanning control unit. This scheme simplifies the circuit and improves the flexibility and reliability of the system. The practical simulation results show that the system displays more content, can better support color display, reduces power consumption, and realizes real-time control display on site.

　　With the continuous updating of flat panel display technology, large-scale LED display systems use dot matrix modules or pixel units composed of light-emitting diodes to form large-area display screens, mainly displaying characters, images and other information, with the advantages of low power consumption, low cost, high brightness, long life, wide viewing angle, etc. In recent years, they have been widely used in stock exchanges, stations and airports, stadiums, road traffic, advertising media and other places.

　　Usually, a single microcontroller is used as the main control device to control and coordinate the large screen display. A multi-processor system composed of multiple single-chip microcomputers, one of which is the main CPU, and the others are sub-CPUs to jointly control the display of the large screen. This system can reduce the burden of the main CPU and increase the refresh frequency of the LED dot matrix. However, the driving frequency of the microcontroller is limited and it cannot drive the LED screen with equal resolution. Especially for the multi-grayscale color large screen, the data must be gray-scale modulated before it is sent to the display screen to reproduce the color of the image, which requires a higher data processing speed. The microcontroller control cannot meet the above requirements in terms of speed. Therefore, this solution is mainly used in occasions where real-time requirements are not high, mainly for the control of static asynchronous displays such as text and pictures. The video image signal has a high frequency and a large amount of data, which requires real-time processing. FPGA/CPLD is used to design the control circuit, in which a large number of circuits such as synchronous control, master-slave control, read-write control and grayscale modulation are integrated, simplifying the system structure, facilitating debugging, and the system structure is compact and reliable. Compared with the single-chip microcomputer control circuit, the circuit structure is obviously simpler, the circuit area is reduced, the reliability is enhanced, and debugging is simpler. Since FPGA/CPLD can process multiple processes in parallel, it is more efficient than the sequential processing of tasks by the single-chip microcomputer, and the refresh frequency of the dot matrix is also increased accordingly.

　　Programmable logic devices are the preferred core data processors for situations with high real-time requirements and large data volumes. This system takes into account the requirements for the size of transmitted video data and the refresh frequency of driving the large LED screen. Both the LED sending card and the receiving card use FPGA as the core processor. XC3S250E-FTG256 is selected, which has 250,000 logic gates and a maximum frequency of 600MHz, which can fully meet the system speed requirements. It is used as a scanning control unit in the system, and the MCU chip is used as the main control unit. This solution can effectively simplify the circuit structure of the display screen, thereby improving the flexibility and reliability of the entire control system.

okhxyyo

Thank you, the information can be uploaded to the download center.

雷北城

Thanks for sharing, I learned a lot!