Topic: Audio Feedback
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Jan 01, 2014, 05:45 pm
I'm working on a lockbox with keypad access and I'm interested in using piezo buzzer audio for feedback, i.e. key presses, incorrect pin, correct pin, etc.
For example, type in the correct 4 digit pin number, press enter and it plays an upbeat tune and then unlocks the box. Same for incorrect pin entries, play a downbeat tune to indicate an incorrect entry.
I know about tone() and the 'Play Melody' example, I'm just trying to figure out how to determine the values to make the sounds that I am looking for.
Any ideas?! Thanks!
Re: Audio Feedback
Jan 02, 2014, 07:21 pm
I'm just trying to figure out how to determine the values to make the sounds that I am looking for.
I think that's a "creative decision" you'll have to make yourself.
If you look at the standard
Western Musical Scale
, two notes next to each other (say B and, C or C and C-sharp) sound dissonant ("sour") when played together or in sequence. If you skip a note (such as C and D, skipping C-sharp) those notes sound "sweet" when played together or in sequence.
Try not to get confused by sharps & flats... C is one full-note above B, and C# is one full-note above C. The spacing between the 12 notes is equal (logarithmically or percentage-wise) but instead of naming the notes A-L, they used A-G with sharps & flats for some notes.
I made a little pass/fail sound routine a long time ago. It runs on a PC, and it was written in BASIC so the actual code would be useless to you. The pass sound is a rising-tone that's supposed to sound pleasing. The fail sound is is two falling-tones that are supposed to sound dissonant .
The sequences are:
500 Hz, 300 ms
700 Hz, 400 ms
900 Hz, 300 ms
500 Hz, 300 ms
150 Hz, 500 ms
450 Hz, 300 ms
130 Hz, 700 ms
These frequencies might be too low for a piezo. If that turns-out to be the case, you can try doubling or tripling them, etc.