基于单片机的倒计时装置设计

基于单片机的倒计时装置设计

摘要

单片机倒计时装置在生活和生产的各领域中应用广泛，凡是有电路自动控制要求的地方都会有单片机设计的身影出现；单片机应用技术已成为工程应用的新技术，单片机应用于产品的小型化、多功能化和智能化，提高了工作效率，降低了劳动强度，提高了产品的质量，减少能源和材料消耗，保证安全等。但是，单片机应用的意义绝不仅限于它的广阔围以及所带来的经济效益上，更重要的意义还在于：单片机的应用正从根本上改变着传统的控制系统设计思想和设计方法。

单片机往往是作为一个核心部件来使用，仅单片机方面知识是不够的，还应根据具体硬件结构，以及针对具体应用对象特点的软件结合，以作完善。本篇论文讨论了简单的倒计时器的设计与制作，此设计是单片机的倒计时装置设计，该装置利用AT89C51单片机作为倒计时器的核心控制器，针对需要倒计时的场合进行可调时间的倒计时功能。其中分和秒都是两位数字显示，键盘预先设置要倒计时的时间，按键启动倒计时装置，数码管动态显示倒计时的画面，当倒计时归零后，发出声音，提示倒计时结束。

关键词：单片机AT89c51；显示电路；数码管；时钟电路；倒计时器

Design of countdown device based on

single chip microputer

Abstract

Singlechip countdown device is widely used in every field of life and production, every circuit automatic control requirements will figure chip design; MCU application technology has bee a new technology in the engineering application, MCU application to product miniaturization, multifunction and intelligence, to improve the work efficiency, reduce labor intensity, improve product quality, reduce the consumption of energy and materials to ensure safety. But the meaning of SCM application not only wide range of it and brought the economic benefits, more important significance lies in: the application of SCM is fundamentally changing the traditional control system design concept and the design method.

SCM is often used as a core ponent, only SCM knowledge is not enough, it should be

based on the specific hardware structure, as well as the specific application of the characteristics of the software bined with the software to improve. This paper discusses the design and fabrication of a simple countdown timer, this design is MCU countdown device design, the device using AT89C51 microcontroller as the core controller of the countdown timer, for applications that need a countdown of time to adjust the countdown function. The minutes and seconds are two digital display, keyboard set in advance to countdown time, button to start the countdown device, digital tube dynamic display countdown screen, when the countdown to zero, sound, indicated the end of the countdown.

Key words:single chip microputer AT89c51; display circuit; digital tube; clock circuit; countdown timer

目录

摘要I

关键词I

Abstract .................................................................................................................................. II 目录III

第一章绪论1

1.1课题的学术背景及其实际意义1

1.2相关领域的成果1

1.3 课题来源及主要研究容2

第二章设计原理3

2.1设计要求3

2.2工作原理4

2.3 程序设计与方案论证4

2.4系统框图5

第三章器件的选择及介绍6

3.1单片机AT89C51 (6)

3.1.1 主要功能特性6

3.1.2AT89C51的引脚说明7

3.2 单片机定时器的使用11

3.3 显示器件选择11

第四章硬件电路的设计14

4.1 硬件电路注意事项14

4.2 硬件电路设计原理图15

第五章各部分电路介绍16

5.1复位电路16

5.2时钟电路17

5.3按键电路18

5.4蜂鸣器电路19

第六章软件设计与流程图21

6.1 倒计时器主程序流程图21

6.1.1 按键流程图：21