Introduction

The 552 QRAP is implemented on the FLEX 10K device on the Altera UP1 board.  An audio signal is input into the device via the CS4223 Audio Codec PCB. That signal is manipulated based on user inputs. The modified signal is output to the codec, then to an amplifier.  Audio signals can be manipulated using various effect algorithms, such as volume control, distortion, and tremolo.  The user can control what effect is applied to the audio signal, as well as adjust the level of the effect.  Alphanumeric displays and LED arrays indicate current effect levels to user.
 

Documentation

Please refer to the following documentation for an overview of 552 QRAP's design and implementation.

• 552 QRAP Final Report (PDF)
• 552 QRAP Datasheet and Specifications (PDF)
• CS4223 Audio Codec PCB Datasheet and Specifications (PDF)
• User Interface Datasheet and Specifications (PDF)

Useful VHDL Source Code

Please notify Anjana Rajan (rajan@ee.ualberta.ca) and Patrick Berry (pjberry@ee.ualberta.ca) when making reference to, or changing any of the following VHDL source code. VHDL code dealing with specific audio algorithms, and component packaging, has been withheld, because we think that it is in the best interests of future students to develop their own implementations based on their own research.

• adc.vhd - Creates a 24-bit audio vector based on serial data from the CS4223 Audio Codec PCB.
• dac.vhd - Generates serial data for the CS4223 Audio Codec PCB based on a 24-bit audio vector.
• clock_divider.vhd - Generates clock signals and constant signals for use specifically with the CS4223 Audio Codec PCB.

Suggested Reading

A number of Student Application Notes were written and referenced during the process of creating 552 QRAP.

Obtaining 24-bit Audio

• CS4223 Audio Codec/PCB Design - Outlines the creation of a PCB, specifically for the CS4223 Audio Codec and 24-bit audio sampling and output (Anjana Rajan & Patrick Berry).
• Clock Divider - Used for synchronizing multiple clocks (Shaun Luong, Clifton Yeung, J.P. Kansky, Patrick Asiedu-Ampem).
• ADC interface - (Charlena Fong, Marc Objois, Mariya Shterngartz, Catherine Single)

Interfacing With the User

• LED, Push Button and Switch Interface - Debouncing multiple button presses (Rob Chapman)
• Alphanumeric LED Displays - Outlines the method of controlling the output to dual Alphanumeric LED Displays. An excellent alternative to 7-segment LEDs or LCDs (Anjana Rajan & Patrick Berry).

Audio Testing

• Testing Audio Algorithms - Discusses a method of testing audio algorithms in software, specifically in C (Anjana Rajan & Patrick Berry).