Secret Knock Door Opener
I. PROJECT OVERVIEW
I occasionally find myself outside my (locked) front door, but without the key. Help me open my door by sensing when I
knock on it with a “teachable” pattern.
II. PROJECT DIAGRAM
Knock in
pattern
Compare to
sequence
Actuate Door
release
Figure 1 – First portion of “Flow Gently, Sweet Afton,” or the melodic basis for the USC Alma Mater, “We Hail Thee, Carolina”
III. REQUIREMENTS
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Develop a system that, when attached to a piece of wood at least 1” thick, can distinguish a specific rhythmic sequence of
knocks of up to 8 beats.
System must be able to work at varying tempos within a specific range suitable for the rhythmic sequence chosen.
The rhythmic sequence should be user programmable. suggest.
Have a rhythmic tolerance threshold of 10%
Illuminate an LED on knock event
Illuminate a series of LEDs (one per measure) for completion of correct knock sequence
For an A: have two distinct knock sequences at least 5 notes in length across 6 beats, with 2 non-quarter notes (8th notes, 8th
rests, half notes)
IV. MIDTERM DEMONSTRATION GRADING
A
B
C
D
F
Show (in ms) the time delay between two knocks
Show 2 knock events by illuminating LEDs
No identifiable progress
V. FINAL DESIGN PRESENTATION GRADING
A
Illuminate a series of LEDs based on two separate knock patterns
with 10% rhythmic tolerance at various tempos based within an
acceptable range for the sequence. Sequences are at least 5
knocks across 6 beats including two non-quarter notes.
Deviation from either pattern will illuminate a single red LED
and require a restart.
B
C
D
F
Illuminate a series of LEDs based on two separate knock patterns
with 10% rhythmic tolerance at various tempos based within an
acceptable range for the sequence. Sequences are at least 3
notes in length across 4 beats with at least one non-quarter note.
Deviation from either pattern will illuminate a single red LED
and require a restart.
Illuminate a series of LEDs based on one knock pattern with 10%
rhythmic tolerance at various tempos based within an acceptable
range for the sequence. Sequences are at least 5 knocks across
6 beats including two non-quarter notes
Illuminate a series of LEDs based on one knock pattern with 10%
rhythmic tolerance at various tempos based within an acceptable
range for the sequence. Sequences are at least 3 notes in length
across 4 beats with at least one non-quarter note
No identifiable progress
VI. PROJECT POINTERS
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There are several ways to transduce vibration to electrical signals. Examine which of these is best suited for an
impulse (knock).
Consider how you will establish the tempo. Perhaps two quarter notes for initial tempo measurement?
Many of the problems may be in the programming. Be sure you have someone capable of thinking algorithmically
for this project