Generally speaking, embedded system is a controllable system with high reliability and real-time performance, which is composed of system hardware and system software. It is designed to meet some engineering applications with high specific requirements. These requirements can be reflected in the specific requirements of the cost, size and power consumption of the embedded system In order to cut the software and hardware parts of embedded system. The development of engineering project for embedded system not only needs professional embedded system development tools and IDE, such as IAR, but also needs cross compiling process between host and embedded system development board.
The hardware system of embedded system is composed of embedded processor, memory and system peripheral equipment. The embedded processor usually includes embedded microcontroller MCU, embedded microprocessor MPU and embedded DSP processor. As a part of embedded system, the core of hardware system, the technology development of embedded processor determines the function and application realization of embedded system products to a great extent.
The software system of embedded system can be divided into three parts: embedded operating system, embedded middleware and embedded application software. Among them, embedded middleware software is a kind of software resources used to help and support the development of embedded application software, usually including database and related software development tools. The embedded application software is a user application program designed and developed based on the selected system hardware platform according to the specific project requirements.
The embedded operating system can be understood as an operating system designed for embedded system. The embedded operating system supports the allocation of hardware and software resources of the entire embedded system, as well as the scheduling and coordination of multi tasks.
In recent years, with the rapid construction of expressways and urban rail transit, the market demands more and more LED displays designed for intelligent transportation. LED display screen can display and release all kinds of road condition information reflecting road traffic conditions in real time, and can provide route selection for road traffic participants, so as to avoid large-scale traffic support phenomenon. As the information display and release method of intelligent transportation system, LED display screen can significantly improve the traffic speed of road network and reasonably distribute traffic flow.
The design functions of LED display screen products involved in the field of intelligent transportation are as follows: the traffic management control center releases the real-time road traffic information to the LED display screen control system installed in the traffic scene through the upper computer software, and the LED display screen completes the traffic guidance work for the driving vehicles by displaying the real-time road traffic information; The control system of LED display screen installed on site can feed back all kinds of information of traffic scene in real time and return to traffic management and control center, so that the working state of LED display screen installed on site can be judged in real time in traffic management and control.
The traditional design scheme of LED display screen control system generally adopts the smallest system composed of single-chip microcomputer, flash memory and static random access memory chip. Among them, the updating of display data and display content and the communication between LED display control system and upper computer are completed by single chip microcomputer. However, with the continuous development of embedded technology and about LED With the increasing demand of display screen function, the problem of limited resources of single chip microcomputer system is becoming increasingly prominent. The LED display control system based on single chip microcomputer has been unable to meet the market demand.
Based on the limitations of the traditional LED display control system, arm and FPGA can be used as the core parts of the LED display control system in the design and application of the actual project. The communication between the LED display control system and the host computer is realized by arm, and the dynamic scanning part of the LED display screen is completed by FPGA.
The communication between the upper computer of traffic management control center and the LED display screen control system installed on the project site can adopt standard computer data serial communication mode and Ethernet communication mode, including RS232, RS485, LAN, optical fiber transmission and wireless transmission.