Final Year Project Eoin Culhane

MIDI Guitar Guitar with 6 outputs 1 output for each string Each individual string output will be converted to MIDI

Project Steps String Pickup Filtering Input to PC Frequency Detection Conversion to Midi Output

Block Diagram

MIDI Musical Instrument Digital Interface A protocol created in 1983 for electronic musical instruments to communicate with each other. Developed for synths but in use throughout music today when dealing with computers and hardware devices.

Uses for MIDI Allows for different instrument sounds to be applied electronically or in hardware without changing the musical notes or tempo. Can be used to send patch and channel information between different pieces of equipment, such as pre-amps, synths and even lighting rigs.

GHOST Saddles These are replaceable bridge saddles for a regular guitar bridge. Each has a piezo crystal built in and has an output cable. A set of 6 gives individual outputs for each string

Saddle Placement Bridge – Where the piezo saddles will be placed

Input to PC To get several simultaneous inputs to a PC I plan to use a multi input audio interface The Presonus Firepod will allow up to 8 and can be connected to a PC via a firewire port

Frequency Detection I will be using frequency detection to determine what note value has being played. The algorithm for this will be programmed in MATLAB To begin I will use simple waveforms for testing with the ultimate goal being wave form analysis on the inputs from the strings

Midi Conversion Once the note has been determined it will be converted to midi There are several values that will need to be generated. Note values, as well as velocity and note on/off signals Midi use was designed for Keyboards but has been adapted for use with other instruments easily due to its straightforward commands

Midi Example

VST To incorporate the Freq Detection in a very usable way I would like to make it into a VST plug-in. These are computer programs that are applied to individual tracks in recording software. They are often effects that can be applied to the track but can range to full blown soft synths (Digital instruments).

VST Implementation VST plug-ins can be used in any audio recording programs, called DAWs (Digital Audio Workstation), which support them. There is a readily available SDK for creating these programs.

Reaper The audio recording program I would like to use for this program is called Reaper It is developed by Cockos, and it offers full VST implementation The inputs from the interface will be routed here and the VST with the code for the project can be applied through this program It is a small, but very capable program that is free to download.

Questions?