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
