Audio Manipulation And Buffers

using DSP-BF533 EZ-KIT Lite

Dr. Veton Z. Këpuska

By Husain Alotaibi

Ahmed 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 9DMA 1 Interrupt

(Sport0 RX ISR IVG 9)

FLAG A_ISR IVG 12Programmable flags Interrupt A

(FlagA ISR IVG 12)

Timer0_ISR IVG 11Timer0

(ISR IVG 11)

ProcessProcess

processor 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