Hello, (some time lurker, first post)
On 17/06/2011 14:27, 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
i am currently building something similar, but triggering synthesis instead of samples. While i can't really comment on my piezos (i had them for a long time until i put them to use), an oscillograph showed they have their biggest peaks between 8.88 and 9ms. The arduinos analogue inputs give values between 0 and 1023 (10 10bits). Using the piezos with or without their shell makes a huge difference in the values propagated to pd. i asked someone more knowledgeable than me about a circuit with the same purpose (just reading the "biggest amplitude" of the piezos response) using http://www.workinprogress.ca/projects/edubeat/source/ but he replied that this specific one would mostly show the characteristics of the capacitor and recommended using a Schmitt-Trigger instead. I'm documenting my project on http://forkbomb.dadacafe.org/blog/ardrum/, it is still a work in progress so not everything is up there yet.
hth,
tee