| With in-depth study and gradually mature of the Linux operating system, it has been widely used. As the economy develops, and China's increasingly demand for power quality, the requirements of the testing equipment are also also improved, so the combination of embedded systems and linux has a broad prospect in the field of power quality.This paper specifies porting the Linux operating system and its application in the measurement of electrical parameters. The u-boot and linux's boot process which can help to grasp their main context and solve the problem is necessary to analyze. And then porting linux and transplanting the root file system. This paper describes the application of embedded linux at the end. The system based on ARM9 and linux OS is designed for measuring electrical parameters such as voltage, current, power, etc., which apply software synchronization algorithms. The system uses the method of zero crossing to calculate the cycle of signal, and then syncs the signal to get synchronous signal to calculate the electrical parameters. Finally, the system uses the FFT to analyze the harmonics.The article introduces the following part:First introducing the development platform. Then describing the transplantation of the u-boot and linux, and introducing the source code of u-boot and linux and the process of AT91SAM9261 loading from DATA Flash. Through analyzing the boot process of u-boot and linux and the hardware environment of the system, modify the source code of the u-boot and linux. Making image of the root file system is an important part of porting linux. This article describes the directory structure of the file system and busybox, and makes directories of the file system and files. Finally, designing and implementing the hardware of the measurement system and writing the code of the A/D driver and applications. The application results show that the linux OS runs stably and the electrical parameter measuring system works well with its high precision measurement. |
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