Design Of LED Graph-text Displaying System Based On Ethernet

With the development of internet and communication technology, embeded system comes into a new historical development stage after nearly 20 year's development.The demand connected the embeded equipment to network becomes more and more intensively, the intelligent electrical appliances,the industry control,the intelligent instrument and the data acquisition are making great steps towards the network. At present, the basic communication protocol using in internet is TCP/IP, it can run in different network.This paper researches how to implement and control a kind of LED screen system based on ethernet technology.In order to manage the hardware resources of the system better and provide a good working environment to the user,embeded operating system usually can be implanted into the embeded system.In my research I choose the embeded Real-Time Operating System uC/OS-Ⅱ.It's code is free,simple and being with fine Real-time, This paper migrate the uC/OS-Ⅱ operating system on the ARM processor LPC2210 and introduce the files supporting the implantation detailedly.LwIP(A Lightweight TCP/IP Protocol) is a embedded TCP/IP stack with the advantage of full functionality,free code and can be implanted easily.The reasons why we choose LwIP are its source code is open and can be used freely and its object codes are very small,this is very important to embeded system having limited resources. Based on EASY ARM2200 platform of Zhou Li Gong Company,this paper migrate LwIP into uC/OS-Ⅱ operating system having been implanted on the ARM processor, realise the basic function of communicating with the ethernet.This kind of screen is made up of controller and displaying board,the chapter four introduces the hardware composition and the chapter five includes the software realization .To check up the correctness of the system design,I complete a LED screen can displays 4 characters and progamm the codes in the controller and the PC.The controller contains the Ethernet protocol and controls the displaying content of the LED screen.Connected the controller and PC to the internet simultaneously.we can control the screen easily.The LED screen in my design can display Chinese charactors,ASCⅡ and black and white pictures.After the confirmation,the implantation of μ C/OS- Ⅱ and LwIP are correct,the design of the whole system can run stably and reliably.