基于音频信号频谱分析的混合光效设计与实现

频谱分析可快速提取信号特征，由于快速傅里叶变换（FFT）具有快速、高效的特性，可以大大降低离散傅里叶变换（DFT）中的运算量，因此被应用于频谱分析中．以FFT为基础，针对采集的音频信号对算法中的倒序住和蝶形运算进行优化，然后利用优化后的算法对不同格式的音频信号进行频谱分析．通过微控制器，利用串行外围设备接口（sPI）协议对SD卡或u盘等物理介质上的多种数字音乐文件进行读取，然后利用音频译码器将数字信号转换为模拟信号进行播放．在播放音乐同时，利用A／D转换器采集模拟信号，利用优化的Fvr算法对其进行分析、提取特征值，然后通过微控制器和脉冲宽度调制（PWM）技术，产生不同占空比的脉冲信号，进而驱动多种色彩的发光二极管（LED）实现多种灯光的动态混合效果．

Design and Implementation of Mixed Light Effect Based on the Audio Signal Spectrum Analysis

Spectrum analysis can quickly extract signal features, Because Fast Fourier Transform （FFT） pos- sesses advantages in computing efficiency, and can greatly reduce the amount of computation comparing to Discrete Fourier Transform （DI~F） , so FFT is chosen in the application for audio signal frequency spectrum analysis. The thesis is based on FFF, aiming at audio signal acquisition, do optimization of the reverse position and butterfly algo- rithm, and then utilize the optimized algorithm to do frequency spectrum analysis about the audio signal in different formats. In the concrete realization of the system, through the micro controller to read a variety of digital music files in Secure Digital Memory （SD） card or U disk and other physical media by using the Serial Peripheral interface （SPI） protocol, then use the audio decoder VS1003 to covert digital signal to analog signal for playing. When pla- ying music, use the A/D converter to do analog signal acquisition, then use the optimized FFT algorithm to analyze and extract the features, and then produce different duty ratios of the realize dynamic mixed lizht. through the micro controller and Pulse-width Modulation （PWM）technology to pulse signal, and then drive Light-emitting Diode（LED） in a variety of color to