Design And Implementation Of Embedded Wireless Printing Terminal

With the continuous development of electronic technology, embedded applications come into more and more areas, for example, an embedded printer comes out recently. With wide applications of WiFi wireless network, more and more devices provides the support to WiFi including printers. In recent years, many manufacturers have produced new printers which support wireless printing capabilities. However, wireless communication modes used by different manufacturers are not unify. Moveover, there are other constraints and limitations. As for the uses, it is neither recognized by many domestic government departments and the companies, nor recognized by the common people.An embedded wireless printing terminal is designed and implemented for self-printing tax form in tax departments. The terminal can access wireless LAN via WiFi and exchange data with the server, which is performed through the soft keyboard. Finally, tax informations are transmitted to the terminal and printed freely. PC is used as a server. The hardware for the Client consists of Tiny6410made by Friendly Arm and touch screen. WiFi wireless network card selectes Ralink RT3070L and printer chooses HP Laserjet1020laser printer.The software of this system consists of the server and client components. In both server and client side, the graphical user interface is programmed by using Qt. In the server side, SQLite database is used to store data and achieve a connection to the database by using Qt. In the client side, the Linux operating system is used. The wireless network card and printer are controlled by porting drivers. Finally, the connection to LAN and the use of printing is achieved. The interface is designed by Qt, which includes welcome window, user login window, main window, and modify password window.The wireless printing system architecture is introduced. The development process of embedded terminal is described in detail. The Qt programming ideas, the use of SQLite database, the use of WiFi wireless network card, the process of controlling laser printer and the process of implementing the TCP connection by using Sockets are highlighted.This system is designed and performed to print tax forms, the results show that the system works well. It can query or update the information in the embedded terminal server, and complete the printing of tax bills. This design is also applicable to some other diffluent or personnel-intensive situations. Furthermore, the research of embedded wireless printing terminals also has a certain practical reference value for the promotion of multi-functional communication terminal of research, popularization and application.