近红外光谱仪光电信号采集电路设计

论文编号:CK060论文字数:13554,页数:32

摘 要

近红外光谱（ NIR ）是近年来发展较为迅速的一种高新分析测试技术，是光谱测量技术、计算机技术、化学计量学技术与基础测量技术的有机结合。本文通过对其中光电信号采集系统这一环节研究和设计，针对它的A/D转换、数据采集及与上位机通信等内容进行分析。光电信号采集系统完成信号的放大处理和模数转换，将采集到的模拟信号转换成计算机可读的数字信号，然后再将数据发送到单片机中进行处理，后与上位机进行通信显示结果等功能。其中放大电路采用芯片op07，转换电路采用ADC0809，单片机采用AT89C51,通信电路采用MAX232及RS232。该电路方案合理可靠，设计简单，性价比高，且提高了电路的稳定性与精度，具有一定的实用价值。

关键词：信号采集、单片机、A/D转换

Abstract

In recent years Near Infrared Spectrum (NIR) is one of the rapid development High-tech analysis and testing technology, which is organic integrated with spectrum measurement technology, computer technology, chemistry technology and the basis of measurement technology. This paper made the research and design based on photoelectric signal acquisition system ,for its A/D conversion, data acquisition and the communication with PC . Photoelectric signal acquisition system is completed with signal amplification, analog-digital conversion, which collected the analog signals and changed it so the computer can read it; then sent the data to the MCU for processing, finally communicating with the computer and show the results . Enlarge circuit which using op07, conversion circuit which using ADC0809, MCU which using AT89C51, communication circuit which using MAX232 and RS232. This circuit is a reasonable and reliable program, is designed simply, cost-effective and it improves the stability and accuracy of the circuit , so it has a certain practical value.

Keywords：Signal acquisition、mcu、A/D conversion

目 录

摘要……………………………………………………………………………. . .……………..I

1 绪论………………………………………………………………………………………….1

1.1 选题的背景与意义…………………...………………………………………………..1

1.2 国内外研究现状…………………………………………………………………….…1

1.3 研究的主要内容和基本要求………………………………………………………….1

2 光电信号放大电路设计...…………………………………………………………….….3

2.1 总体电路设计…………………………………………………………………….……3

2.2 op07芯片介绍…………………………………………………………………............3

2.3 放大及滤波模块设计……………………………………………………………….…4

3 A/D采集电路设计…………………………………………………………………..…...6

3.1 系统总体结构框图………………………………………………….……..………….6

3.2 ADC0809和AT89C51芯片介绍…………………………………… ………………6

3.2.1 ADC0809…………………………………………………… …………………6

3.2.2 AT89C51……………………………………………………… ……………….9

3.3 AT89C51与ADC0809接口电路……………………………………………………11

3.4 A/D转换的技术指标…………………………………………………………….….13

4 单片机与PC机串行接口电路设计…………………………………..……………..15

4.1 系统总体结构框图……………………………………..………….…………………15

4.2 RS-232C标准与MAX232芯片简介………………..………………………………15

4.2.1 RS-232C标准………………………………………………………………….15

4.2.2 MAX232芯片简介……………………………………………………………16

4.3 接口通讯………………………………………………………………..…………….16

4.3.1 串口通信………………………………………………………………………16

4.3.2 串行通信………………………………………………………………………19

4.5 串行接口电路设计……………………………………………………………..…...20

5 总结………………………………………………………………………………………....23

致谢……………………………………………………………………………………………...24

参考文献………………………………………………………………………………………25

附录一 ADC0809与单片机通信程序…………………………………………………26

附录二 单片机与PC机通信程序……………………………………………………...28