Guitar 0.1 (gesture acquisition)
The aim of our sensing system is to acquire gestural information from left hand movements. For that purpose, an array of capacitive sensors was mounted on the fretboard of the guitar. These sensors provide information relative to the presence of fingers into that specific fret. Specifically, depending on the number of fingers present in a given fret, the position of these fingers, and the pressure of the fingers to the strings, the response of the sensors differ.
Guitar 0.2 (hexaphonic acquisition)
Hexaphonic pickups are able to send an independent audio stream for each string. Their use is quite common on acoustic and electric guitars but, in nylon guitars, it is more difficult to design such transducers. Solutions using piezoelectric pads mounted on the bridge exists. As our goal is to propose an universal setup, we used a Roland GK-3 pickup connected to the StringPort. In order to capture vibration from nylon strings, we attached a small steel string between the bridge and the string, as shown in the following figures. Although the measured audio is colored by the resonances of this small steel string, we obtain quality enough for the analysis.
Fretboard 0.1 (gesture acquisition)
As a previous step for building a complete augmented guitar, we decided to build a small fretboard (only 4 frets) to analyze the technology we will use. Here, the capacitive sensors are made by brass pieces and electrically shielded inside the fretboard. We want to analyze its behavior in terms of stability, crosstalk and robustness. This piece has been built by Paul Poletti.