基于TMS320F2812数据采集与CAN总线传输.doc

摘　　要 目前，数据采集系统广泛应用于科研，教育，工业，水利等众多领域。随着计算机和信息技术的飞速发展，数字信号处理已经成为高速实时处理的一项关键技术，而数字信号处理器（DSP）芯片的出现为实现数字信号处理算法提供了可能。 本系统采用TMS320F2812作为核心处理器，完成四路模拟信号的数据采集，将采集后的数据暂存在片内存储器中，进行数字滤波后，传输到计算机显示。F2812有丰富的片内外设，用它作为处理器进行电路设计，可以使电路结构设计简单，成本低，开发周期相对短。 数据采集部分，采用F2812内部自带的12位AD转换模块，由于F2812内部存在增益误差和偏移误差，对系统的精度有一定的影响。数字滤波部分，采用FIR滤波器，利用MATLAB的FDAtool软件来实现。数据传输是基于CAN总线完成，利用的是F2812上的eCAN模块，采用TI公司的SN65HVD230作为收发器，它是CAN协议控制器和物理总线的接口。并完成了对自动换挡电路模块、隔离电路模块，有效值转换电路模块的设计。 关键词：TMS320F2812；数据采集；FIR数字滤波；CAN总线 ABSTRACT Currently, data acquisition systems are widely used in scientific research, education, industry, irrigation. With the rapid development of computer and information technology, digital signal processing technology has been more and more important in high-speed and real-time processing. The appearance of DSP chip makes the arithmetic of digital signal processing come true. Based on TMS320F2812, our system completes the acquisition to four anolog signal.The acquisited data is storaged in the chips memory temporarily, then it is filtered and transmitted to PC. As this chip has abundant of peripheral, we can have a simple circuit architecture, a low cost and a short development time by using it. In A/D part, we use the 12-bit ADC of the chip. Due to the internal errors of the F2812 influence the system percision, we give the ways to improve sampling precision.In the digital filter part, we design FIR filter.In the system,we use FDATool in the Matlab.Data transmission is based on CAN bus.We use F2812 eCAN module.The transceiver is SN65HVD230 of TI company, which is the interface of CAN between CAN controller and physical bus. And we design the automatic range selection circuit module,isolation circuit module and the RMS converter circuit module. Key words:TMS320F2812；data acquisition；FIR digital filter；CAN bus 目 录 第1章 绪论 1 1.1 论文研究的背景和意义 1 1.2 数据采集系统国内外研究现状 2 1.3 论文研究的主要内容 4 第2章 数据采集系统的核心电路设计 6 2.1 系统总体实现方案 6 2.2 DSP芯片的选取 6 2.3 TMS320F2812芯片的介绍 9 2.4 TMS320F2812最小系统的设计 13 2.5 A/D模块设计