电子课程设计论文.docx

电子课程设计实验报告项 目： 激光无弦琴目录摘要„„„„„„„„„„„„„„„„„„„„„„„„„1关键词„„„„„„„„„„„„„„„„„„„„„„„„1Abstract„„„„„„„„„„„„„„„„„„„„„„„„1Keywords„„„„„„„„„„„„„„„„„„„„„„„„1一、引言„„„„„„„„„„„„„„„„„„„„„„„1二、激光琴简介„„„„„„„„„„„„„„„„„„„1三、激光琴原理„„„„„„„„„„„„„„„„„„„21、基本原理„„„„„„„„„„„„„„„„„„„„„„22、功能结构原理„„„„„„„„„„„„„„„„„„„„23、系统组成部分„„„„„„„„„„„„„„„„„„„„24、工作原理„„„„„„„„„„„„„„„„„„„„„„2四、单片机原理说明„„„„„„„„„„„„„„„„„3五、电路原理图„„„„„„„„„„„„„„„„„„„41、感光部分电路„„„„„„„„„„„„„„„„„„„„42、发音电路„„„„„„„„„„„„„„„„„„„„„„4六、流程图„„„„„„„„„„„„„„„„„„„„„„5 七、实验所需器材„„„„„„„„„„„„„„„„„„5八、电路实物图„„„„„„„„„„„„„„„„„„„6九、改进方案设计„„„„„„„„„„„„„„„„„„6 十、激光琴未来发展之路„„„„„„„„„„„„„„6 十一、结束语„„„„„„„„„„„„„„„„„„„„6 参考文献„„„„„„„„„„„„„„„„„„„„„„7 附录„„„„„„„„„„„„„„„„„„„„„„„„„7项目课题：无弦激光琴摘 要：伴随着激光技术的发展和广泛应用，激光已不仅在农业、工业、医疗 上得到广泛应用而且激光在与电子技术结合也得到了很好的体现。

利用 5 个激光 管发出的光束作为琴弦，利用单片机控制拨动激光琴弦时发出不同音调的声音， 当在激光照射时单片机读取光敏电阻的电压为低电平，令它的逻辑电平为0；当 无激光照射时单片机读取光敏电阻的电压为高电平，令它的逻辑电平为1因此 当遮挡激光的光线时它就能在电路中产生开关的效果因而，当我们用手遮挡激 光的时候对应的光敏电阻的电压为高电平，此时激光琴就会发出声音，连续遮挡 不同的激光管就能演奏出动听的音乐 关键词：激光管,激光技术,激光琴,光敏电阻Project: The laser harpAbstract Along with the development and wide application of laser technology, the laser has not only been widely used in the agricultural industrial medical and laser in combination with electronic technology has also been well represented. We make the five beam emitted from the laser tube as the strings use of single-issue and produce different tones of voice. SCM detect photosensitive resistor at both ends is low when the laser irradiated, so it's logical level 0 and the photosensitive resistor voltage read by the microcontroller when the laser irradiation is high so it logic level 1. Therefore, when the laser light was covered, it make an efficiency of the switch . Thus, when we block the laser by hands the resistance of the photosensitive resistor corresponding voltage is high, the laser piano will sound, and the laser tube will be able to play a fantastic music while covering different laser light.Keywords: Laser tube; Laser Technology; Laser piano; photosensitive resistor一、引言激光琴是一种没有琴弦的琴，逐渐代替琴弦的是一束激光光束。

当你用手去 遮挡光束时，激光琴会发出相应音符的声音，和按不同琴键而发出不同音符的声 音一样，十分有趣，能够吸引读者的积极性在把握光电效应的同时我们更要掌 握激光琴的原理和使用方法激光琴主要是利用光电效应可以把光信号转变为电 信号，动作迅速灵敏我们研究他的每一束光束由每一个激光点所发出的不同音 调和音色与普通的琴类所发出的音调和音色是否完全相同，每遮挡一个光束时激 光琴发出的声音与琴类的各个琴键或琴弦的所发出的声音与之相对应，但由于本 次设计用的是无源蜂鸣器，所以音色可能没有琴弦发出的声音那么纯正二、激光琴简介激光琴是指一架没有琴弦的琴，取而代之的是激光光束，演奏者只需拨动 光束，便如同拨动了琴弦，就可演奏一段旋律能给观众得到光和声相结合的美 感，与传统的琴类相比，激光无弦琴更能体现它的自动化和全能化三、激光琴的原理1、基本原理在自然界，有些物质一经光照射，其内部的原子就会释放出电子，使物体的 导电性增加原来电阻很大的材料，在光照下，电阻就会变得很小，这种现象叫 做光电效应用这种材料可以做成光敏元件，对电路进行光控，利用光学控制原 理制作的激光琴，使得演奏者无需用手接触琴身，而只需用手遮住一束光， 无 弦琴就会发出声音，相当于拨动一根琴弦。

经过不停地对光控制，可以“演奏” 出不同的音阶和乐曲 在日常生活中，激光琴可以作为游乐景点的休闲设施供 游人弹奏，而不用担心破坏琴键，不用担心染上细菌2、功能结构原理激光琴是一种以光束作为琴弦的乐器本次设计的激光琴较为简单，其结构 主要由5 个激光管构成的发射部分、五个光敏电阻与 52 单片机构成的感应部分 和一个无源蜂鸣器构成的响应部分三部分组成，通过单片机串行口进行数据传 输，当用手挡住五根激光束中的一根时，蜂鸣器响起与之对应的五个音节中的一 个，连续遮住不同的激光束时能演奏出简单的音乐3、系统组成部分整个激光琴系统分为发射、感应及响应三部分(1) 发射部分：由五个激光管发出激光束模仿琴弦构成 激光管发射的集中且亮度较高的红外线有利于感应部分的光敏电阻较敏感地感 应光强变化从而产生较明显的阻值变化2) 感应部分：主要由光敏电阻和 AT89C52 单片机两部分部分组成 激光管发射的光束被挡住时，对应的光敏电阻感应并产生阻值变化，五个光敏电 阻组成的系统产生高低电位的变化，并由单片机读取光敏电阻高低电位变化，完成操作指令的输入，单片机根据指令信息来控制数据通过串行口传输数据，对其 输入信号进行判断，然后对接蜂鸣器的P3.7 口进行高低电平的赋值，使其产生 相应的反应，输出相应频率的方波。

3) 响应部分： 主要是一个无源蜂鸣器，蜂鸣器根据单片机输出的不同频率方波输出不同的音 调，可以对应不同竖琴琴弦发出不同频率的声音4、工作原理当有激光照射时，光敏电阻阻值变小，单片机读取光敏电阻的电压，此时它 为低电平当无激光照射时，光敏电阻阻值变大，单片机读取光敏电阻的电压， 则这时它为高电平这样，当遮挡激光的光线时，就能在电路中产生开关的效果人耳能听到的声音频率为20Hz至20kHz，竖琴音符频率也应该在此范围 只是，不同的音符，有着自己固定的频率通过52单片机自带的16位定时器就 可以产生上述音频一般音乐电路是以正弦波信号驱动喇叭以产生音乐，而在数 位电路里则是以脉动信号驱动例如竖琴的标准音la为440Hz通过计算可知， 它的半周期为1136“这样，只要在半周期时跳变引脚电平，就可以产生440Hz 的方波了再经过电声转换元件(蜂鸣器)，就可以产生标准音la 了，其他音符 也是这样产生的至于音调，如图为 C 调音阶表，包括高、中、低三个音阶，每个音阶为八音 度，每个音阶之间的频率相差一倍音階n123456789101112DoDo#ReRe#MiFaFa3SoSo*LaLa#Si低 音頻率262277294311330349370392415440464494簡譜1234567中 音頻率523554587622659698740784831880932988簡譜1234567高音頻率104611091175124513181397148015681661176018651976簡譜■234567表1 c調音階-頻率對照表四、单片机原理说明管脚功能说明：1、 VCC：电源电压。

2、 GND:地3、 P1 口： P1 口是一个8位双向I/O 口口引脚P1.2--P1.7提供内部上拉电 阻,P1.0和P1.1要求外部上拉电阻1.0 和P1.1还分别作为片内精密模拟比较器 的同相输入(ANI0)和反相输入(AIN1)P1 口输出缓冲器可吸收20mA电流并能直接 驱动LED显示当P! 口引脚写入“ 1”时, 其可用作输入端，当引脚P1.2--P1.7用 作输入并被外部拉低时，它们将因内部的 写入“ 1”时，其可用作输入端当引脚(T2) P1-0(T2 EX) P 1 1P1 _2 P 1 1P1 4P1.5P1.6 P 1 .TRST (RXD) P3.0 (TXD) P3. J(S N7 F U- J P3-.2(INT 1 J P3 3 (TQ) 4 (T1 } P3.5