Audio Manipulation And Buffers using DSP-BF533 EZ-KIT Lite

Dr. Veton Z. Këpuska

By Husain AlotaibiAhmed Alalyak

ECE 3551 Microcomputer ECE 3551 Microcomputer System ISystem I

Spring Spring 0808

IntroductionIntroduction

Audio Manipulation through Changing the gain

Introducing a delay

Using Low and High Pass Filters (FIR)

Implementation Scope

-without any push button pressed the audio is transmitted to the speakers with no modification

pressing PF8 will increase the volume of the audio and LED 1 will be on when the volume is in the first step LED 1+2 is lit and so on up to LED 5 then it resets

Pressing PF9 will decrease the volume of the audio and Corresponding to the value of the current volume a specific range

of LED’s will be lit to indicate the volume level Further pressing will decrease the number of lit LED’s until it resets

Implementation Scope Pressing PF10

Activates chorus effect and lit LED 3 Activates Low Pass filter and Lit LED 4 Activates High Pass Filter and lit LED 5 Fourth press will reset to default mode

Pressing PF11 will change the spanning with each press until it resets

PreparationPreparation

SW9 pins are all on

Initialization and enabling the six

LED’s and the four Push Buttons

Interrupts usedInterrupts used

System Interrupts Defined Core Event Name Description (Comments)

SPORT0_RX_ISR IVG 9 DMA 1 Interrupt(Sport0 RX ISR IVG 9)

FLAG A_ISR IVG 12 Programmable flags Interrupt A(FlagA ISR IVG 12)

Timer0_ISR IVG 11 Timer0 (ISR IVG 11)

ProcessProcessprocessor start at main() in main.c. This

program calls a various initialization routines to set up the EZ-Lite boards in a configuration that is needed for audio input/output, then it executes an infinite loop.

Process (continue)Process (continue) This program is an interrupt driven

program which means that the computer program only does something when a hardware interrupt is generated. 

Process (continue)Process (continue) File Process_Data will contain the user

computational functions

In ISR functions will facilitate calling the

computational functions and give their output

Effects and implementations simple operation that can be performed

in a DSP on an audio signal to create a volume control

Audio Panning Control uses gain to create a phantom source by varying the gain.

Chorus

Implementation of buffers to create a delay

The buffer will be used to read and write values each sample period, and incrementing to the next memory location for each sample.

Filters

Using MATLAB, we designed two filters and imported their coefficients.

used a circular buffer method to compute the output signal.

Issues

Much significant complication and problems are with the quality of the audio

Noise is the dominant problem in this project

Results & ConclusionResults & Conclusion Successful development of an acceptable

approach to implement popular audio effects

The board offers a broad usability in different fields

Appreciating this encouraging class