David Chang, Brady Mayes, Chris Olson,

1
The Real Guitar Hero
David Chang, Brady Mayes, Chris Olson, Erick Van
Houten, Vince Valera
dmc044000_at_utdallas.edu, brm016000_at_utdallas.edu,
cto021000_at_utdallas.edu, epv021000_at_utdallas.edu,
vgv013000_at_utdallas.edu
Department of Electrical Engineering Erik Jonsson
School of Engineering Computer
Science University of Texas at Dallas Richardson,
Texas 75083-0688, U.S.A.
Project Results
Project Goals

• Signal Processing
• Band Pass Filtering
• Circuit Schematic and simulation - 2nd Order
• 
  Correct HI Incorrect LOW
• Beat Detector schematic (above)

• To convert the analog output of an electric
  guitar into a digital signal and sent to a
  processor via USB
• Design the unit so that it can operate solely on
  the power provided in a USB interface

Project Overview

• Amplification of Original Signal from Electric
  Guitar
• Hide variable impedance of source
• Increase power of the signal to make it simpler
  to work with
• Processing of Signal
• Band Pass Filtering -
• We used an active band pass filter to detect the
  different
• frequencies or notes that the guitar can
  play.
• There were 51 band pass filters made for the 51
  notes of the guitar
• The signal would pass through each filter and
  would display a HI value if it is within the
  bandwidth or a LOW value if it is not.
• This output would then be sent to the
  decoder/encoder stage.
• Beat detection -
• Purpose to detect when the guitar string is
  struck.
• Method Full wave rectification of the circuit,
  Low Pass filter, then
• Voltage comparator.
• This method detected when there was an amplitude
  change in the
• input signal.
• Decoder/Encoder-

Project Conclusions/Outcomes

• Band Pass Filters We were able to separate all
  frequencies from each
• each other and signal a HI value (4.1V) if
  the band pass filter received a
• correct signal and a LOW value (0-0.1V) if
  the band pass filter received
• an incorrect signal. All signals read
  correctly for different amplitudes as
• well and the output was then sent to the
  encoder/decoder.
• Amplifier implemented using a op-amp positive
  feedback loop.