[PD] Piezo, trigger, Arduino

[Roman Haefeli]

Hi Pierre

Actually, I wouldn't connect the piezos to an arduino, but to a sound
card, because the piezos will likely give very very short spikes and the
sampling rate of the analogIns of the arduino is quite low (don't know
the exact value) compared to the sampling rate of a common sound card.
Also, you have more control in Pd to build a trigger detection filter
then on the arduino. Also you would likely get much lower latency with a
good audio setup than with the atmega->ftdi->usb->comport path. Also
when using the soundcard, the latency is constant, while you would have
glitches with the arduino.

I'd be glad to hear other opinions, though, since my thoughts are purely
theoretical. I haven't implemented a piezo-based trigger, neither with
sound card nor arduino.

Roman

On Fri, 2011-06-17 at 14:27 +0200, Pierre Massat wrote:
> Dear List,
> 
> This is yet another question about Arduino. Sorry about that. 
> I want to use piezos to trigger samples using my arduino board. I want
> the trigger to be sensitive, and a quick google search seems to show
> that piezo is the way to go. 
> Does anybody have any experience with piezo triggers (what type of
> piezo, isolating each piezo, etc.)? I will hit the piezos with my bare
> fingers (no drumsticks or anything like that), but i guess it doesn't
> really matter since i can control the threshold within Pd. 
> 
> This last sentence is just to make sure that everyone knows i'm
> talking about piezos in case there wasn't enough occurences of the
> word in my message. 
> 
> Cheers!
> 
> Pierre
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