[bonk~] may not be the ideal unit for the job, though I am sure it will work, it might be a bit elaborate to set up if you are new to it.
I made something similar once, I'm guessing the piezos are those very thin kind, silver solder on one side and usually fixed with a blob of epoxy, as you get in musical greetings cards (?).
They are basically mid/high frequency transducers, with a peak somewhere about 5kHz. I seem to remember that on a drum skin they gave a very bouncy signal and to get them to work I had to put a RC passive lowpass in there to settle them down a bit and avoid multiple triggers.
[bonk~] is quite a sophisticated object that matches brief signal patterns. You train it with a stack of examples to match and it does its best to identify occurances of the same pattern in the input stream.
For a bongo trigger I suppose you really just want a single trigger. Something as simple as
[lop~ 400] | [threshold~ x]
might be all you need. Place 3 of them at 120 degrees around the skin and you can work out where on the skin the impact occured...a la Korg Wavedrum or Roland DP(?).
On Tue, 26 Jun 2007 13:35:13 +0200 "henrik wurster" henrik.wurster@gmail.com wrote:
hello gang,
I have a project with pd using piezo sensors attached to my bongos underneath the skins. they actually work not too bad as microphones, but what I want to do is trigger the strokes being played on the bongos. in the end I want to trigger matching samples which I recorded previously. in my research how to detect small percussion instruments, I stumbled upon the bonk object, but don`t know how to work with it, because I am really new to pd...:) I dont expect any patching, but can anybody help me to give me an idea how I could start buiding the patch ? I thought about loading the samples into an array, but does bonk work at all checking sounds with recorded samples ? thanks for any piece of advice
best regards,
- henrik
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