Overview
The purpose of the auto-chromatic instrument tuner is to help
musicians match the intonation of their instrument with a reference
pitch, or concert pitch, which may be best described as matching the notes
on a piano. To maximize the usefulness and practicality of the tuner, there
will be three different ways in which to tune: automatic tuning mode,
manual tuning mode, and audible reference pitch mode. In automatic
tuning mode a note is played, and the tuner matches the input pitch
to the closest reference pitch. The manual tuning mode allows the user
to select the reference pitch to be compared against. An advantage
of manual mode is faster operation, since the tuner does not have to search
for a reference pitch before making the comparison. Finally, the
audible reference pitch allows the user to tune the instrument by ear.
This mode is particularly useful in tuning large ensemble groups.
Inputs
· DC Power Supply
· Microphone: Converts pitch into an electrical signal
· Power/Mode Switch: Switches between Off mode, Automatic
Tuning mode, Manual Tuning mode, and Audible Reference Pitch Tuning mode
· Pitch Selector: Selects pitch and octave in Audible
Reference Pitch mode and selects tuning note in Manual Tuning mode
Outputs
· Pitch Indicator: Three character 7-segment display which
indicates the letter name, whether it is natural or flat, and the octave
of the pitch that is to be detected. For example- En5, Gb2 would
indicate E natural, fifth octave and G flat, 2nd octave.
· Analog Tuning Display: An analog meter which will demonstrate
how close the note is to a reference pitch. The meter will range
from -50 cents to +50 cents, indicating a range between half-way to the
next highest chromatic pitch or half-way to the next lowest chromatic pitch.
· Digital Tuning Indicator: A series of LED’s which will
give a discrete minimal error of how close the user is to the desired reference
pitch. A central green LED will indicate a perfectly matched pitch.
Two yellow LED’s outside of the center LED will indicate if the pitch is
within 10 cents (or 10%) of the central pitch. Finally, two red LED’s
surrounding the yellow LED’s will exhibit that the pitch is more than 10
cents away from the indicated pitch.
· LED/LCD Bar Indicator: May replace the Digital and Analog
Tuning Displays by displaying a light or marker at the place the input
pitch is in relationship to the reference pitch.
· Speaker: Will produce the reference pitch as an audible
sound to the user.
Modes of Operation
· Off: No power is input into the system
· Automatic Tuning Mode: Based on the pitch received by
the microphone and transmitted into the tuner, the closest reference pitch
is found and subsequently indicated on the display along with both the
analog and digital indication of how close the received pitch is to the
reference pitch.
· Manual Tuning Mode: The user selects the reference pitch,
indicating its octave, and the pitch received by the microphone is then
compared to this pitch.
· Audible Reference Pitch Mode: Again, the user selects
the reference pitch and octave, and the output is an audible tone which
may be used as a point of reference for obtaining that desired pitch.
Figure 1: Front Panel of Auto-Chromatic Tuner
1 | Power Supply |
2 | Microphone |
3 | Power Mode/Switch |
4 | Pitch Selector |
5 | Pitch Indicator |
6 | Analog Tuning Indicator |
7 | Digital Tuning Indicator |
8 | Speaker |