新疆农业大学科学
课程名称：
学生姓名： 完成时间： 技术学院
课 程 设 计 报 告
单片机原理与应用
梁保军
2015年7月2日
I
系（部） 课程实训题目 姓 名 同组实训者 指导教师 指 导 教 师 评 语 机电工程系 专业班级 简易电子琴设计 农电122班 梁保军 梁保军 杨涛 吴毅 组 别 实训时间 2015.6.15至2015.7.2
指导教师签名： ______年 ____ 月____日
实训 成绩
II
摘 要
本次设计为简易电子琴设计，利用8051单片机内定时器和I|O端口，设计一台简易电子琴，能通过按键进行简单的乐曲演奏。每个不同的音符对应着不同的频率，利用单片机内部定时器TO结合I|O端口来产生不同频率的方波信号改变TO的计数值即可改变不同的音符。
关键词：8501单片机 音符 频率 内部定时器
III
目 录
一、概 述 ··················································································································· １
1.1 课题设计目的及其意义 ······················································································ １ 1.2 课题设计的任务与主要内容 ················································································ １ 二、基本组成和原理 ····································································································· １
2.1 音乐相关知识 ·································································································· １ 2.2 简易电子琴基本原理及其框图 ··········································································· ３
2.2.1基本思想 ································································································ ３ 2.2.2硬件框图 ································································································ ３ 2.2.3软件设计流程图 ······················································································· ４
····················································································· ４ 3.1 元器件清单及其电路图 ·
3.2 单片机89C51的简介 ························································································· ５ 3.3 键盘电路 ········································································································ ６ 3.4 振荡电路 ········································································································ ７ 3.5 复位电路 ········································································································ ７ 3.6 音频放大电路 ·································································································· ８ ·································································································· ９ 四、 系统软件的设计 ·
··························································································· ９ 4.1 系统的软件主程序 ·
·················································································· １２ 4.2 系统的软件的调试仿真 ·
总结 ······················································································································· １３ 参考文献 ················································································································· １４ 附录 ······················································································································· １５
附录1简易电子琴PCB二维图 ··············································································· １５ 附录2简易电子琴PCB三维图 ··············································································· １５
IV
基于单片机简易电子琴
一、概 述
1.1 课题设计目的及其意义
单片机（单片微型计算机）是大规模集成电路技术发展的产物，具有高性能、高速度、体积小、价格低廉、稳定可靠等特点。单片机的应用相当广泛，从平常的家用电器到航空航天系统和国防军事、尖端武器都能找到它的身影。因此，单片机的开发应用已成为高科技和工程领域的一项重大课题。
随着社会的发展进步，人们的生活水平也逐步提高，音乐已经成为了我们生活中很重要的一部分，在工作和学习之余，欣赏音乐不仅使身心得到放松，同时也提高人们的精神品质和个人素养。当代，爱好音乐的年轻人越来越多，也有不少人自己练习弹奏乐器，作为业余爱好和一种放松的手段，鉴于一些乐器学习难度大需花费太多精力，且其价格太过于高昂，使得一部分有这种想法的人不得不放弃这种想法，而电子琴又是一种新型的键盘乐器，它是现代电子科技与音乐结合的产物，价格相对便宜，能够满足一般爱好者的需求，因此，在现代音乐中扮演着重要的角色。 故简易电子琴的研制具有一定的社会意义。
1.2 课题设计的任务与主要内容
本文的主要内容是用AT89C51单片机为核心控制元件，设计一个简单的电子琴。以单片机作为主控核心，与键盘、扬声器等模块组成核心主控制模块，在主控模块上设有16个按键和扬声器。定时器按设置的定时参数产生中断，由于定时参数不同，就会发出不同频率的脉冲，不同频率的脉冲经喇叭驱动电路放大滤波后，就会发出不同音调。
先根据要求设计硬件电路和编写相应的程序，然后进行仿真调试，最后细心焊接硬件电路图，将程序烤入芯片中，最终达到设计目的。本系统运行稳定，其优点是硬件电路简单，软件功能完善，控制系统可靠，性价比较高等，具有一定的实用和参考价值。
具体实现的功能：按下音符键可以发出相应的音符。
二、基本组成和原理 2.1 音乐相关知识
在人类还没有产生语言时，就已经知道利用声音的高低、强弱等来表达自己的思想和感情。声带、琴弦等物体振动时会发出声波，声波通过空气传播进入人耳，人们就听到了声音。声音有噪音和乐音之分振动有规律的声音是乐音，音乐中所用的声音主要是乐音。
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