Design Of Hardware And Realization Of Software For Electronic Whiteboard Based On ARM

In order to expand the application of Electronic Whiteboard, and realize the aims of portability, availability, multifunction, and economy, it is necessary to design a portable intelligent equipment - Electronic Whiteboard system based on ARM(EWB-ARM), which can be used to do research, work and do some amusement etc.EWB-ARM adopts embedded technology, and is developed on the basis of interactive wireless orientation Electronic Whiteboard system, which has been developed by Signal Detection & Processing Laboratory in Jilin University. EWB-ARM is the embedded terminal used to assist the research, design and education on Internet. The launch and gathering signal module adopts advanced infrared and supersonic localization technique, and in signal processing module, the high performance ARM9 processor S3C2440X, produced by SΛUMNG, is used to construct the hardware platform, while Microsoft Windows CE is used to build the software platform; the time-delayed data from gathering module are transmitted using USB interfaces. The main functions of EWB-ARM are as follows(1) Write freely in a range of 1.2m×1.8m with real-time display on LCD, preserve writers'natural handwriting. Four colors of signal pen are available, facilitating the discrimination of writing time, postil and so on.(2) Copy the writing content and homework to flash disk or SD card directly and be connected to the printer and print the content.(3) The integral multimedia player can broadcast the audio and video files. Due to the 2D graph acceleration function of the SM501, high video effects can be obtained.(4) The picture browser can glance over bmp, jpg pictures.(5) The network browser can surf the Internet. (6) Some games are available for entertainment.This dissertation is a part of the Jilin Province Science and Technology Development Key Project "highly alternative service information terminal (No.: 20060329)", and it is mainly on signal processing module, including the design of hardware and the realization of software. The dissertation is divided into six chapters.The first chapter introduces research background and the significance of ARM-based Electronic Whiteboard system, elaborates the components, characteristic and application of the whole system.The second chapter summarizes the localization algorithm of wireless orientation Electronic Whiteboard, and then the localization algorithm of ARM-based Electronic Whiteboard system is discussed.The third chapter designs the hardware circuit in signal processing module of ARM-based Electronic Whiteboard system. The chips for hardware circuit according to the system requirement are selected, and memory circuit, net card circuit, host and device USB circuit, SM501 video card circuit, sound card circuit, power source and replacement circuit, UART circuit, JTAG circuit are designed, respectively.In chapter four, Windows CE, the embedded operating system, and its driver structure are discussed. The suitable operating system for the dissertation is customed, and many functions, such as broadcasting audio and video multimedia document, glancing over pictures and Word files, browsing website, printing and entertainment, are completed. Then USB driver for DM4604 Electronic Whiteboard is programmed and is successfully debugged, which lay the foundation for data transmission.In chapter five, application procedure under the embedded operating system Windows CE is completed. Then application program for ARM-based Electronic Whiteboard system is programmed using Embedded VC, and the functions of real-time display and preservation of the content are realized. The application program is debugged and tested on the development board.In chapter six, a brief summary of this dissertation is given, and some existing problems and futher research aspects are put forward.The main contributions of the dissertation are as follows(1) Considering the shortcomings of the RS– 232,such as the slow transmission speed and big volume, in this dissertation, the USB connection is used in Electronic Whiteboard system based on ARM. Thus, the volume of the whole system is reduced, the transmission and processing speed is high, and real-time displaying the handwriting is realized. What's more, USB driver of EWB-ARM and application program are developed, which lay the foundation for data transmission using the USB connection.(2) Since the biggest distinguish of LCD screen is 800×600, it can not smoothly broadcast MPGE1, the MPGE4 multimedia documents in a higher resolution, even though the VGA connection is used. In order to resolve this problem, the S3C2440X processor and acceleration chip SM501 which has the video and the 2D ability are used in EWB-ARM, and SM501 circuit is designed.The problems, which need to improve in future, are as follows.(1) The system has realized some basic functions, such as real-time writing, preservation and browsing. But in order to realize high quality writing, error data must be removed. In addtion, multi-pages writing and printing, mutual operation are also needed.(2) Due to the limited time, the dissertation just designed the hardware circuit, and the PCB circuit need to be debugged with software in the next step.