The Design Of Portable Embedded Devices Interface

Portable embedded devices have been applied everywhere in our life.More and more people are aware of the embedded devices played a huge role in promoting the process of social change and development.Although there are many different kinds of embedded devices,they have a lot in common,the difference exists on the interface,and these complex interface is the important bridge of communication between embedded operating system and external equipment.Thus the design of software and hardware interface of embedded equipment has become an important part of embedded system design.Currently when doing detection and control of a large engine equipment,we need many large test equipments to complete in a specific occasion,And poor precision,the function is not perfect,use not convenient.Currently the portable instruments equipped with embedded Linux system nonsupport the function of CD writer and printer,some printers support direct printing during embedded Linux system environment,but it need high software licensing fees,and the price of this kind of printer is quite expensive,and linux driver doesn't support the clock chip,thus urgently need to research the embedded high precision,multi-function portable instrument for testing a big engine equipment.This paper relies on the project of a portable measurement and control device of a large engine,we studied the hardware and software development environment of embedded portable instrument.and researched the arm-based processor,and designed Linux operating system-based software and hardware platform and Linux operating system-based architecture and compiled the drive principle of Linux device.We also designed the bottom interface circuit of core board's hardware platform which based on the AT91SAM9263,the cutting transplant of U-BOOT and Linux operating system,the production of root file system.Finally we analyzed the driver of Linux-based Inter-Integrated Circuit bus and the universal serial bus framework.And designed the Linux-based driver of domestic real-time clock with a crystal-made and USB-based micro printer system,support many cheap printer,configuration realizes USB recorders.Finally extended the interface of embedded device,enhanced the generality of instrument.A special portable test and control equipment was designed in this paper,which equipped with Linux operating system,Support cheap printer,external domestic clock module,function of CD writer.we can develop the embedded graphics interface on the device.During the process of designing we fully considered these factors: the principle of electromagnetic compatibility,the limited storage resources of embedded devices,the real-time of embedded systems,the extensibility of embedded devices,and we have proved that field application has a good performance.The design scheme of this paper has a good practical value and realistic significance to the design of embedded-system-based intelligent product.