Research And Implementation Of Data Acquisition System Based On Raspberry Pi

The development and innovation of data acquisition system is powerfully promoted by the continuous development of computer technology, sensor technology and communication technology. Nowadays,the data acquisition system plays a key role in the field of industrial equipment detection diagnosis. This thesis is based on the on-line diagnosis monitoring system project of Baosteel industrial technology service co., LTD. In order to realize the intelligent, networking, software and hardware can be cut, low power consumption and the multi-channel data acquisition system, a data acquisition system based on Raspberry Pi is designed and implemented in this thesis.The main contents of this thesis are as follows:In the first place, by analyzing actual demand of this project and comparing to multiple hardware and software development platform of various vendors, this project selects the Raspberry Pi which adapts the Raspbian on the basis of the Linux kernel as the system control and development platform that is constructed on the ARM11. Secondly, by studying the SPI (Serial Peripheral Interface) bus protocol and SPI driver framework in Raspberry Pi’s kernel, the module that SPI bus driver directly drive data acquisition card based on Raspberry Pi platform is designed and implemented, which realizes the multi-channel data rapid acquisition. A case of hardware interactive development by using the open source framework of Python language is achieved in the field of industrial production. Then in this system, a method which uses ring buffer to realize data synchronization in the process of data acquisition is presented and which is applied between data acquisition and data processing modules whose speed mismatches with each other so as to realize the data synchronization process of data acquisition system. According to the characteristics of data acquired, this project uses FFT(Fast Fourier Transform) algorithm for data processing and optimizes data processing and make full use of Raspberry Pi’s strong ability of floating point calculation to build a foundation for the spectrum signal to realize data analysis and processing, which improves the accuracy and efficiency. In order to analyze data acquired and display data playback, the preservation of historical data is realized. In the data display module, data display and waveform figure drawing on PC is realized based on PySide and Matplotlib tools which are Python language supported.Through the acquisition system in the system testing in various aspects, the final results show that the design and implementation of data acquisition system based on Raspberry Pi meets the demand for equipment to detect the state diagnosis of data collection, the running effect of modules meet the design requirements.