音頻信號分析儀設(shè)計(jì)

  摘要：  本音頻信號分析儀由32位MCU為主控制器，通過AD轉(zhuǎn)換，對音頻信號進(jìn)行采樣，把連續(xù)信號離散化，然后通過FFT快速傅氏變換運(yùn)算，在時(shí)域和頻域?qū)σ纛l信號各個(gè)頻率分量以及功率等指標(biāo)進(jìn)行分析和處理，然后通過高分辨率的LCD對信號的頻譜進(jìn)行顯示。該系統(tǒng)能夠精確測量的音頻信號頻率范圍為20Hz-10KHz，其幅度范圍為5mVpp-5Vpp，分辨力分為20Hz和100Hz兩檔。測量功率精確度高達(dá)1%,并且能夠準(zhǔn)確的測量周期信號的周期，是理想的音頻信號分析儀的解決方案。

　　關(guān)鍵詞： FFT  MCU  頻譜 功率

　　Abstract: The audio signal analyzer is based on a 32-bit MCU controller, through the AD converter for audio signal sampling, the continuous signal discrete, and then through the FFT fast Fourier transform computing, in the time domain and frequency domain of the various audio frequency signal weight and power, and other indicators for analysis and processing, and then through the high-resolution LCD display signals in the spectrum. The system can accurately measure the audio signal frequency range of 20 Hz-10KHz, the range of 5-5Vpp mVpp, resolution of 20 Hz and 100 Hz correspondent. Power measurement accuracy up to 1%, and be able to accurately measuring the periodic signal cycle is the ideal audio signal analyzer solution.

　　Keyword: FFT  MCU  Spectrum  Power

　　

1  方案論證與比較 3

1.1  采樣方法方案論證 3

1.2  處理器的選擇方案論證 3

1.3  周期性判別與測量方法方案論證 3

2  系統(tǒng)設(shè)計(jì) 4

2.1  總體設(shè)計(jì) 4

2.2  單元電路設(shè)計(jì) 5

2.2.1  前級阻抗匹配和放大電路設(shè)計(jì) 5

2.2.2  AD轉(zhuǎn)換及控制模塊電路設(shè)計(jì) 6

2.2.3  功率譜測量單元電路設(shè)計(jì) 6

3  軟件設(shè)計(jì) 7

4 系統(tǒng)測試 8

5  結(jié)論 9

參考文獻(xiàn)： 9

附錄： 9

附1：元器件明細(xì)表： 9

附2：儀器設(shè)備清單 9

附3：電路圖圖紙 10

附4：程序清單 11