Research And Design Of Audio Signals Analyzer Based On TMS320F28335

Spectrum analysis has a wide range of applications in production practice and scientific research. Specially, low-frequency signals under 50KHz is widely used in the fields of industrial control, teaching experiment, vibration and biomedical. From one hand, the commonly used sweep frequency spectrum analyzer can not meet the requirements of high accuracy real-time in the analysis of low frequency signals. On the other hand, the specific audio signal analyzer to measure low-frequency are expensive, it is difficult for ordinary users to buy this high cost equipment.As real signals are often time-varying and non-stationary, it is very effective to analyze the signal spectrum using short time Fourier transform method which could overcome the deficiencies of traditional Fourier transform to make the results more accurate. This paper described the Fourier transform, fast Fourier transform (FFT) and short time Fourier transform theory, and the short time Fourier transform FFT algorithm to achieve the short-time Fourier transform a fast run on the DSP chip, which provide a possibility to measure signal spectrum in real-time manner.This paper designed an audio signal analysis system integrated with signal acquisition, processing and display that can accurately measure those low-frequency spectrums under 50KHz. In details, High-precision A/D converter PCM1804 is responsible for signal acquisition, its sampling frequency could be reached to 192KHz, as the core digital data processing of this system, TMS320F28335 DSP in charges of data processing and related control function. Touch screen LCD with high definition was chosen to display an interface which is easy to design, simple to control and flexible to operate.This paper also presented the history, feature and development environment of digital signal processor, elaborated design process of this system, belowed are the major work.①This paper designed DSP-based hardware system, draw the hardware circuit diagram of this system, described MCU module, data acquisition module, power management module and LCD module in details.②This paper designed software system, including general ideas, system flow charts, particularly FFT operation and spectrum display. To verify the feasibility of the system, experiments have been successfully conducted. Experimental results show that this system can measure the spectrum of low frequency signals with high precision and real time feature.