摘 要

目前国内外市场上的电子琴都比较昂贵，故难以普及受益于万千家庭。电子琴演奏者对音色的要求不高，那么用成本低、可靠性高的单片机制作一款电子琴便成了优选的方案。为此，作者运用单片机设计了一款简易儿童智能电子琴，它具有基本的播放音乐、调节音量，录放声音的功能。该篇论文就此详细介绍了简易儿童智能电子琴的系统控制硬件组成，以及如何利用STC89C52单片机驱动三极管控制扬声器发声，通过ISD4004语音芯片实现语音的录放，通过Altinum Designer 6.9实现了原理图的设计。除此以外，还谈及运用C语言进行按键识别程序的设计，通过硬件软件的反复联调，由proteus仿真出来，并制作出实物。笔者把7个按键设置成7个音节，通过一个音频放大模块来使音乐播出的声音变大，使玩具功能更完备，更激发孩子的兴趣。通过不同的音节和节拍的组合，预先将程序写入单片机中，构成了十首耳熟能详的歌曲。智能儿童电子琴不仅具有传统电子琴的弹奏功能，还具有播放多种音乐、录音和放音的功能，使孩子们在快乐的玩耍中学习音乐，达到益智的效果。其主要优点是成本低廉、性能可靠、结构简单。因为没有很多的键位，录入的10首歌曲就可供使用者参照操练，简单易学。

关键词：儿童智能电子琴；语音芯片；STC89C52单片机；设计

The Design of a Simple Children's Intelligence Organ

ABSTRACT

Those on the market at home and abroad are so expensive that it’s difficult for electornic organs to be either popular among tens and thousands of families or beneficial to them. Because of the fact that electronic keyboard players are not so particular about tones,it’s a good idea to use the single chip microcomputer,which not only costs less but also is relatively more reliable,to produce an electronic keyboard . The one that the writer desiged and produced in this way has several functions, such as playing music,adjusting volumn and recording.This article introduces in detail the simple children intelligent electronic keyboard’s components of the system control hardware and how to employ STC89C52 MCU to drive triode to the speaker , how to realize the dream of playing voice through ISD4004 voice chip and how to accompolish the design of schematic diagram through Altinum Designer 6.9. Besides, the article also covers how to use C language to identify the design of the program by pressing keys. The material object is produced through the repeated alignment of the hardware and software ,and then through proteus simulation.Seven keys are set into seven syllables, making the sound of the music broadcast loud via a broadcast audio amplifier and making the functions of toys more complete so as to arouse children’s interest.By combining different syllables and tempos, the program is written into the single chip microcomputer, constituting the ten well-known songs.Not only does the intelligent children keyboard possess the function of playing as a traditional one did but also it has other functions ,including broadcasting many kinds of music, recording and playback, so that children can learn music while playing,which is sure to benefits children’s intelligence. Its main advantage includes low cost, reliable performance and simple structure.Due to the fact there are not many keys, the 10 recorded songs are easy for players to practise and learn if players want to refer to .Therefore, from now on the appreciation of music really steps into common families.

Keywords: Children’s Intelligence Organ ; Voice Chip; STC89C52 single-chip microcomputer; Design

目 录

1 前言 - 1 -

1.1 课题研究的目的和意义 - 1 -

1.2 国内外同类研究概况 - 2 -

1.3 我的设计内容及实现功能 - 3 -

2 简易儿童智能电子琴的方案设计及论证 - 4 -

2.1 简易儿童智能电子琴设计描述 - 4 -

2.2 简易儿童智能电子琴总体设计方案 - 4 -

2.3 简易儿童智能电子琴各模块设计方案的选定 - 5 -

2.3.1 主控芯片的选定 - 5 -

2.3.2 录音模块的选定 - 6 -

2.3.3 按键模块的选定 - 7 -

3 简易儿童智能电子琴硬件系统的设计 - 8 -

3.1 单片机最小系统的设计说明 - 8 -

3.2 语音录放模块的设计说明 - 9 -

3.3 独立式键盘的设计说明 - 9 -

3.3.1 独立式键盘的概述 - 9 -

3.3.2 独立式键盘按键识别原理及方法 - 10 -

3.3.3 独立式键盘的功能设计说明 - 10 -

3.4 扬声器的设计说明 - 11 -

4 简易儿童智能电子琴软件系统的设计 - 13 -

4.1 简易儿童智能电子琴主程序流程图 - 13 -

4.2 按键播放音乐流程图及部分程序 - 14 -

4.3 录放音模块程序流程图及部分程序 - 17 -

4.4 七个音调的程序设计及部分程序 - 19 -

5 系统调试 - 23 -

5.1 系统调试环境 - 23 -

5.2 调试操作过程 - 23 -

5.3 系统调试结果 - 24 -

5.4 系统调试心得 - 25 -

6 结论与展望 - 27 -

6.1 结论 - 27 -

6.2 展望 - 27 -

致谢 - 29 -

参考文献 - 30 -

附录一 简易儿童智能电子琴总程序 - 32 -

附录二 预先录入的十首歌曲简谱图 - 78 -

附录三 简易儿童智能电子琴原理图 - 83 -

前言

1.1 课题研究的目的和意义

随着时代和音乐的发展，乐器变得越加多样化，一言以蔽之，无非管弦二类。而当下的流行音乐，大多是各种乐器的混响。为了能够满足可以演奏出多重音色但仅需一种乐器的需要，电子琴应运而生，并且越来越受到人们的青睐，在教学和演奏方面相当适用。

电子琴又称电子键盘，是一种采用大规模集成电路，大多配有声音记忆存储器（波表）的合成器。它有别于传统的乐器,后者是通过机械的方法振动发声的，而电子琴是通过“电”产生的。振荡器是根据需要产生一定频率的振荡信号，通过分频器分解成不同频率输送到放大器，信号被放大后推动扬声器发出声音。电子琴的键盘实则是一些开关，按下一个开关，发出对应的音调。如此按照一定的规律来演奏，即可构成美妙的乐曲。如果没有键盘，音乐就会杂乱无章地混杂在一起。