Variable Effects System (example project from AY 2014-5)

by Aaron Ma (EE), Andrew Toledo (CpE), KEvin Huynh (CpE), and Wesley Kuang (CpE) [Team #3]
Mentor: Pai Chou

(if the video is not playing, try https://youtu.be/1N-T6FEzIcg)

The Problem:

• Effects pedals today pertain to guitars.
• While there are many effects for guitars, violins and other stringed instruments virtually have no effects

Solving the Problem:

• Use an embedded system to that accept any audio input
• Manipulate the audio input and output it

The Goal:

• Create a way to add effects to violins and other instruments through an embedded system. Design effects that are tailor made to other instrument.
• Use Digital Signal Processing, to create a “Chamber Effect” and more.

The Technology:

• TMS320C6713 DSP Starter Kit by Texas Instruments
• MATLAB has built in functionality to generate code with CCS v3.
  • CCS v3 compatible only with Windows XP
  • Workarounds could not link CCS and MATLAB together 
• Code Composer Studio v.5
  • IDE with support to TI microcontrollers
  • does not natively support DSK6713
  • Workarounds allow for perfect execution

Assigning Multiple Effects

• Daughter Cards:
  • Externally control the SDK
  • $100+, low support
• DIP switch attached to the DSK6713
• Able to select different states
• Decided not to solder onto board

Effects:

• Pre-sets
  • Chamber Effect, Chorus, Cosmic
• Stand-Alone:
  • Metronome, Low-Pass, High-Pass, Distortion

Evaluation:

• Ended up filling all the available spots on the DIP Switches
• Sounds are able to be manipulated and enhance a wide range of songs
• Opens the music field to new effects (DJs)

Lessons:

• What worked:
  • Able to adapt
• What didn't work:
  • Too ambitious
• What we would do differently:
  • More affordable board

Conclusions

• We were able to create a way to add effects to instruments and existing music
• Paves the way for new sounds in music today