基于AT89C51单片机的八路抢答器设计方案

毕业设计(论文)-基于AT89C51单片机的八路抢答器设计

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毕业论文

基于AT89C51的八路抢答器设计OCTAL ANSWER DESIGN ACCORDING ON AT89C51

班 级学 号学生姓名学院名称信电学院专业名称电子信息工程技术指导教师

2010年05月20日 摘要

本设计是以八路抢答为基本理念。考虑到依需设定限时回答的功能，利用AT89C51单片机及外围接口实现的抢答系统，利用单片机的定时器/计数器定时和记数的原理，将软、硬件有机地结合起来，使得系统能够正确地进行计时，同时使数码管能够正确地显示时间。用开关做键盘输出，扬声器发生提示。同时系统能够实现：在抢答中，只有开始后抢答才有效，如果在开始抢答前抢答为无效；抢答限定时间和回答问题的时间可在1-99s设定；可以显示是哪位选手有效抢答和无效抢答，正确按键后有音乐提示；抢答时间和回答问题时间倒记时显示，满时后系统计时自动复位及主控强制复位；按键锁定，在有效状态下，按键是无效的。

关键词: AT89C51；LED数码管；抢答器；计时

Abstract

In this design octal answer is the basic idea. Taking account for the function of answering the question in the limit time, we utilize the answer system which is consisted of AT89C51 microcontroller and external interface, and the principle that use SCM timer to time and counter to count to make the hardware and software combined organically, so the system can time correctly and the digital LED can display the time correctly. The keyboard output is switching, speaker play sounds. In the system the goals which can be achieved: when the competitors race to be the first to answer a question ,it is effective that they press the buttons only after the master says “begin”, otherwise it is invalid; The digital LED competitors answer in a limited time and the time to answer questions can be set in 1-99s; The LED can display is the numbers who are effective and invalid, and the music will tells who is effective; The system count the time for competitors racing to answer and answering questions by countdown . When the time is zero, the system will restore; While Keys are locked, the key is invalid in effective condition.

Keywords AT89C51 Nixie tube Button Loudspeaker Reset electric circuit

目 录

1 绪论1

1.1 背景1

1.2目的与意义1

1.3 课题研究的内容1

2 系统概述2

2.1 系统的主要功能2

2.2 系统需求分析3

2.3 抢答器的工作流程3

2.4 抢答器的工作过程4

2.5 器件的选择5

2.6 AT89C51功能及简介5

3 系统总体方案的设计7

3.1 硬件电路的设计7

3.2 硬件原理图7

3.3 时钟频率电路的设计8

3.4 复位电路的设计9

3.5 显示电路的设计10

3.6 键盘扫描电路的设计11