毕业设计论文-基于PIC单片机SPI接口的数据采集模块设计.docVIP

基于PIC单片机SPI接口的数据采集模块设计 摘 要 PIC单片机比MCS-51单片机功能更强大，因为其内部集成了A/D转换模块、USART通讯模块及MSSP端口；本文介绍一种基于PIC16F877A单片机的数据采集模块的设计。首先主机的A/D端口接电位器，实现模拟电压向数字信号的转换，然后对转换后得数据通过SPI接口传输给从机，从机通过显示控制芯片HD7279A，最后通过四位数码管把采集的模拟电压显示出来。 系统需要两片单片机完成，分为主机和从机，主机完成数据的采集、A/D转换，转换结果的输出，从机主要完成数据的接受，工程量变换功能。程序采用C语言编写，在集成开发环境MPLAB-IDE下完成编译及程序下载，最终实现能通过调节电位器实现变化的电压显示。 关键词 PIC单片机 数据采集 A/D转换 SPI接口 DESIGN OF DATA COLLECTION SYSTEM BASED ON THE SPI PORT of PIC MICROCONTROLLER ABSTRACT The function of PIC MCU is more powerful than MCS-51, because it integrate a large number of on-chip peripherals such as AD converter module. USART communication module and MSSP port, This article introduced the design of data collection system based on the SPI port of PIC MCU, first the ADC converter module is connected with the potentiometer, so the analog voltage can be converted to digital signal, and then send them to the master microprocessor by the SPI port, The slave display the analog voltage through multi-point calibration which is controlled by the HD7279A. It needs two pieces of microcontroller to do the job, which is divided into the master and the slave, the former completes data collection, A / D conversion, the conversion results of output, and the later accepts the data transmission as well as the quantity change. C language is used in programming, the MPLAB-IDE integrated development environment completes compiling and downloading. And finally the analog voltage is displayed. KEY WORDS PIC MCU Data Collection AD Conversion SPI Port 目 录 摘 要 I ABSTRACT II 1 绪论 1 1.1 课题背景及研究意义 1 1.2 本设计方案介绍 2 2 硬件部分设计 3 2.1 PIC单片机介绍 3 2.1.1 PIC单片机的优越之处 3 2.1.2 PIC16F877A最小系统图及主要性能 4 2.2 PIC单片机片内ADC模块及接口实现 5 2.2.1 ADC模块结构和操作原理 5 2.2.2 ADC模块相关的寄存器介绍 6 2.2.3 A/D转换接口电路设计 7 2.3 主控同步串口MSSP介绍 9 2.3.1 I2C总线介绍 9 2.3.2 SPI 简介 10 2.3.3 SPI主模式接口设计 13 2.3.4 SPI从模式接口设计 14 2.4 HD7279A芯片原理介绍及接口实现 15 2.4.1 HD7279A简介 15 2.4.2 HD7279指令介绍 16 2.4.3 HD7279A的接口实现 20 2.5 电源模块 23 3 软件设计程序流程图 25 3.1 C语言编程简介 25 3