Decrease octave works on all notes
Yes
Reset sends system to note mode and default octave
Yes
No sound plays if no tactile sensors are engaged but accelerometer
detects
Yes
No failure if user holds the chord/up octave/down octave/reset buttons
instead of pressing them
Yes
Playing one note and another in quick succession should cut off the
first note (no overlap)
Yes
Response time and performance
Yes - Note selection
is instant to a
human’s reaction
time. Accelerometer
threshold may need to
be varied slightly per
user for comfort.
Table 6: Hardware test plans
Results of Experiments and Characterization
Strum Detection:
Due to the difficulty in interfacing the accelerometer, a backup distance sensor was used
in its place temporarily. The sensor had a maximum 30 cm range for detection of movement. It
was still small and light enough for the purpose of this system, but had to be positioned more
specifically to catch the user’s right arm strums. There is also the option of attaching the sensor
to the player’s waist. An issue is that sensor will not differentiate between up and down arm
movements, and so a user may unintentionally play twice as they raise their arm to strum again.
However, the delay required between detections is extremely small and not noticeable even when
one is waving their arm as fast as possible.
In the end, the accelerometer was chosen as the detection device because it had a myriad
of extra features the distance sensor did not. This is discussed in the Appendix - Future Work.
The accelerometer also did not need special positioning or have any range issues as it was
attached and wired directly onto the right glove. For the I2C interfacing to work with the DE2
board, however, there is a 150 ms delay between the interrupts fired upon detection.
CPU Clock/Performance:
19
