The Network Guitar
This project was the result of a collaboration with an AHRC/New Media
Scotland funded research group LEAPP (Laboratory for Laptop and
Electro Acoustic Performance
NetGuitar is my performance instrument developed specifically from
network based improvised performances. It is a standard electric
guitar that has been hacked with many additional features. Extra
cavity space has been created in the body of the instrument with a
milling machine and a custom scratch plate was designed and laser cut
to enclose this new cavity area. The new cavity now contains a beagle
bone embedded linux computer and an arduino, the arduino takes
information from many new sensors, accelerometers and linear and
radial potentiometers, switches and buttons all mounted on the custom
scratch plate. The NetGuitar communicates to the base station over the
zigbee wireless communication protocol and also has a standard RJ45
ethernet port, an android mobile phone running the controlOSC appis
also attached to the guitar . Amp emulation is performed using an
instance of the free and open source guitarix software, subsequent
processing achieved using puredata (both receiving OSC control
messages via zigbee). The bass station also hosts an OSCGroups Server
and wireless access point for easy inter-ensemble communications
should they be needed.
After returning from LLEAPP I set to work on testing some technologies, primarily I researched solutions based around the open hardware Arduino combined with an accessory "shield" to provide wireless communications with the laptop base station using the Zigbee Protocol. I also looked into other cheaper solutions such as the JeeNodes and SenseStage Arduino derivatives. Despite the ease of using Arduino based solutions I was unhappy with options for wireless connectivity. Ideally I would use an Arduino with a WiFi shield so I could quickly and easily join the existing OSC server network but the cost of these two components along with a base station reciever was too great compared with my current choice, the Beagle Bone.
The next step in the augmented guitar was to carve a cavity in the body of the guitar big enough to hold the beagle bone along with the wiring for all the additional controls and to design and cut a new scratch plate to hold all the new electronics.This part of the job was done at the London Hackspace using their woodworking tools (forstner bits in bench press drill) and laser cutter.
The scratch plate was designed in Inkscape, a free and open-source cross platform vector graphics editor and converted to paths for the laser cutter using LibreCad. The sound processing software was migrated from Pure Data to SuperCollider. The OSCGroups Server that was previously hosted on an external Raspberry Pi server could now also be hosted within the body of the guitar itself on the same computer as was dealing with the analogue and digital sensor inputs.