Remote AMR System Design Based On AT91RM9200

With the development of economy, more and more domestic meters, such as energy meter,water meter and gas meter, are widely used in daily life.Various kinds of Automatic Meter Reading(AMR) systems have been designed, which not only reduce the need for troublesome manual work, but also establish the technical base for providing better services and earn good economical effect and social effect.This paper engages in research of building a remote AMR system, and presents the solution that the embedded system based on ARM processor AT91RM9200 is used to solve the present problems. The solution adopts the embedded Linux Operationg System as the embedded software platform that can help to develop the embedded applications by providing standard API. The system makes full use of network function provided by the embedded Linux Operationg System, and performs networking by networking protocol of Socket in developing networking applications. At the same time, a database is set up at the server to maintain the data collectted from all kind of meters.The basic idea of the project is to customize a embedded development platform that can satisfy all actual requirements. For obtaining the platform, it is the main work that we tailor the embedded operating system on the hardware developmnet platform, delete redundant functions, reserve requisite functions, and develop applications to solve actual problems on this basis.In a word,the project buildes a remote AMR system from three aspects : the hardware platform,the operating system and the applications.1,The project designs the structure of the AMR system. It focuses on the core component-the controller of collection and transmission. After considering the requirements of the whole system, the project decides to adopt the embedded platform based on ARM processor AT91RM9200 as the controller.2,After analyzing the embedded hardware platform, the project chooses embedded Linux OS as the software platform of the whole system. The paper discusses how to build a embedded Linux OS on the embedded system depending on actual needs. On this stage, the paper put a strong emphasis on the building of cross-platform development environment,the port of bootloader(U-Boot),the configuration of the kernel and the building of root filesystem.The embedded Linux OS is the heart of the whole system that controlls the operation of the whole system, and distributes the whole resource. The building of the embedded OS is the most important and complicated step that involves whether the whole system could operate reliably.After studying the boot process of Linux OS and the particularity of the embedded system, the project decided to use host/target cross-platform development mode. In this mode, the host takes charge of building cross-platform development environment and complete most of the development work. At last, the binary code is downloaded to the target platform and run.The Linux kernel,cross-platform development tools,Bootloader and root filesystem are completed by many individual development teams independantly, so they don't synchronize usually. We must deal with the problem carefully and avoid making a conflict.3,Once the embedded software platform has been established, the project starts developing independent applications on the target and the host to realize the AMR system. The applications on the target mainly implement the functions of data collection,data processing and network communication. The applications on the host mainly implement the functions of network communication and database management. They cooperate together and compose the whole AMR system.In the process of building the system, the project studies the structure of Linux OS deeply and focuses on the filesystem and process communication mechanisms. It adopts the technology of socket and pipe during developing the applications, and builds the module of Linux device driver. At last, we realize the remote AMR system basically, and found the base to the future application of the embedded system.