Frequency analyser to VGA display

Abstract

Digital Signal Processing (DSP) is the process of the modification of a signal input to a system, which will later be used for the system's needs. The data which is used in the system is mathematically manipulated to suit the requirements of the project or function being carried out. In this project, DSP is used to the extract continuously changing frequencies of an analog signal using the Fast Fourier Transform (FFT), an algorithm used to compute the frequency components of an analog signal. In the case of this project, the analog signal to be used is a sound wave, for instance the analog output of music from earphones. The sound wave is used as analog input to an Analog to Digital Converter (ADC). An ADC converts analog to digital signals, which once sampled and converted digitally, can be implemented by the FFT. The main aim of this project is to extract the frequency components of the analog input signal as accurately as possible using an 8-Point FFT and have them displayed. Once obtaining the 8 frequency components, the magnitudes of the separate frequency components are found, and the results further displayed on a VGA monitor. Therefore the VGA monitor should output 8 vertical moving bars, continuously moving and changing to the analog input signal. The results obtained from the FFT were successful, acquiring values which matched the results calculated using the theoretical equations. The magnitude results were also correct with respect to how the project was implemented and programmed. Therefore overall expected results were obtained.