I am musician, and a full-time Software Developer with over 15 years experience designing and building software solutions!  I am also a hardware junkie, and quite often can be found tinkering with old 8-bit computer systems.


Here is an example of a previous project, presented at Syntax 2012 :  SID Sampler








Looking forward to getting started!






The goal of my project is to produce a tool for guitarists to vastly enhance the guitar experience for their guitar by providing effects expression and control through the plectrum.


The guitarist will be able to "trigger" effect based upon pluck direction to create unique playing styles, not previous possible.




Technical Overview


These DSP type effects will be generated by the Beagle Bone Black in realtime by making use of the unique Programmable Realtime Unit(s).  This will require the production of C code to process audio data in realtime from ADC to DAC/HDMI.




Realtime DSP Processing


The methods to produce realtime Digital Signal Processing effects is well documented and available to port to the Beagle Bone Black.  The types of effects can include Chorus, Delay, Phasing, Tremolo, Distortion, Compression and Filtering.  The BBB contains two Programmable Real-time Unit Subsystems.  These programmable real-time units allow the creation of real-time applications, whilst still allowing the simultaneous operation of the core processor, for operating system functionality.





Code Composer Studio will be used to target the PRU.  I will initially be implementing a real time band-pass filter effect





Input Control


The main input control for my purpose will be the plectrum Piezo transducer, this will be analyzed in mealtime to determine the direction of pluck / strum.  ie. Up / Down direction.


  • 1) In one incarnation of the idea a single Piezo transducer is used to determine the amplitude phase direction to determine the strum direction.


  • 2) In another incarnation, two (2) Piezo transducers are used to determine the direction of strum.







Hardware Design


I plan to create a custom PCB for the audio input output connects and plectrum (piezo transducer).    Eagle will be used for the hardware design.




I believe that there are risks to the project, like for example :


  • The parts and components not working as expected
  • Development time
  • Bugs



Thanks again!