摘 要
为方便人们的日常生活，优化学校、机关等单位的计时系统，采用以单片机为基础设计了一种的自动音乐播放器。本设计利用单片机89C58RD+的定时和计数功能，来完成时间的显示和定时功能。并且，通过对定时器初值的设定来产生不同频率的声音，利用定时器中断来完成对音乐节拍长度的控制。通过LM386N1音频功率放大器，将单片机输出的信号放大，再通过喇叭播放乐曲。通过MAX232型芯片，可以转换PC机上的电压和单片机的电源电压，再通过串口接入PC机，这样就能从PC机上将用C语言编写的程序下载到单片机上。最后可在数码管上显示时间，当定时时间到后，喇叭自动播放一段连续的音乐。此设计摆脱了传统闹钟的刺耳声音，取而代之的是美妙的音乐，能为人们的日常生活提供准确的计时，且成本低廉，值得推广。
关键词:单片机；自动音乐播放；音频转换；时间显示；LM386N1音频功率放大器
The design of automatic music player based on monolithic integrated circuit
Abstract
In order to facilitate people's daily life, optimizes schools’, institutions’ timing system, used has designed one kind of automatic music player which based on monolithic integrated circuit. This design fixed time and counts the function using monolithic integrated circuit 89C58RD+, completes the time the demonstration and fixed time the function. And, Through hypothesis starting value of timer, product the different frequency sound. Severs using the timer completesthe control of music metre length.Through LM386N1 audio power amplifier, enlarges signal which the monolithic integrated circuit outputs,then broadcast music from loudspeaker. Through MAX232 chip,can transform PC machine on the voltage and the monolithic integrated circuit supply voltage.And then,turns on the computer though String mouth,then it can download procedure which compiles with the C language to monolithic integrated circuit from computer.At last,it can demonstrates the time on the digital tube.When time to after fixed time, the loudspeaker automatically broadcasts section of continual musics. This design get rid of the traditional alarm clock’s grating sound, displaces is the wonderful music,can provides the accurate time for people's daily life.The design cost very inexpensive,it is worth promoting.
Key word：Monolithic integrated circuit; Automatic music broadcast; Audio frequency transformation; Time demonstration; LM386N1 audio power amplifier
目 录
范文总页数：页
引 言.......................................................................1
1 设计任务................................................................2
2 软件设计
2.1 音乐编程原理及流程图 ...............................................
2.1.1 声音的产生 ......................................................
2.1.2 音频转换原理 ....................................................
2.1.3 音频转换流程图 ..............................................
2.2 时间显示程序设计..............................................
2.2.1 时间显示模块..............................................
2.2.2 时钟流程图 ..............................................
3 硬件电路的设计..............................................................2
3.1 硬件流程模块（此节作为第1节---后面几节就围绕它来写，并且要写“连贯”）
3.2 主要模块电路的设计..........................
3.2.1 89C58RD+型单片机介绍.........................................
3.2.2 LM386N及外围电路的设计............. ...............
3.2.3 串行通信和MAX232芯片...........................................
3.2 4 AT89C52的定时/计数器概述.........................................
3.2 5 LED显示原理...............................................