Design Of Soft-Keyboard Based On Embedded LINUX

With the rapid development of computer technology, embedded system is more and more widely used. By now, embedded computer system is much more than common computer in quantity. Embedded system is a new direction of technology development after IT network technology. With the prominent advantages of small volume, powerful performance, low power dissipation, high reliability and special purpose, embedded system is widely used in fields of national defence, consume electronic, network communication, industry control and so on. With the development of computer and communication technology, research and development of embedded system are more and more useful.Firstly, this thesis presents the concept and the structure of embedded system and then introduces hardware and software. Some processors based on ARM on current market are also presented in the paper. The embedded system selects S3C2410X of Samsung, which is based on ARM920T. Because of its excellent kernel design and applied performances, Linux is running on all kinds of hardwares. Linux also owns other merits, such as its free source code, its inherit network functions and its modularization design in kernel. Therefore Linux is very suitable to be the operating system of embedded system. After comparing various embedded operating systems, this system selects Linux.Although Linux operating system has much superiority, but applications on the professional terminal device is a new topic with many challenges. On one hand, there is not only elaborate embedded design thought and system's structure based on S3C2410X but also transplant and compilation of Linux kernel in this paper. On the other hand, there is including the foundation of both IDE and GUI on Linux. This thesis is about a programme of scanning keyboard through timer interupt style. Microprocessor scans the matrix of keyboard regularly in order to assure wether the keyboard is pressed namely through inputing low charge in a cycle and then read the row value. If the values are all high charge then distinguish the next line, otherwise there is a key pressed in this line and here is get the line and row values of this key, finlly you get the value of key according to the line and row value.