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
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 _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Hi Roman, thanks for your reply. I'm afraid i can't use a soundcard to capture the input from the piezo (I don't want to buy one just for three little triggers). If what you're saying is true i guess i will just use three switches and forget about the sensitivity.
Pierre
2011/6/17 Roman Haefeli reduzent@gmail.com
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 _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management ->
ej pierre regarding sensitivity a FSR = force sensitive resistor might be interesting as well?! salutis ø
On 06/17/2011 03:15 PM, Pierre Massat wrote:
Hi Roman, thanks for your reply. I'm afraid i can't use a soundcard to capture the input from the piezo (I don't want to buy one just for three little triggers). If what you're saying is true i guess i will just use three switches and forget about the sensitivity.
Pierre
2011/6/17 Roman Haefeli <reduzent@gmail.com mailto:reduzent@gmail.com>
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 > _______________________________________________ > Pd-list@iem.at <mailto:Pd-list@iem.at> mailing list > UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
I found that it works better if you put some kind of peak detector op-amp circuit between the piezo and the arduino.
See the peak detector circuit in here: http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/part8/Page3.html
The diode rectifies the signal and the capacitor stretches it out so the arduino has time to measure it, the resistor drains the capacitor so it doesn't hold the peak forever.
Putting weights on top of the piezos increases their output, as does gluing them to a resonant object.
Martin
On 2011-06-17 08:53, Roman Haefeli wrote:
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 _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
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
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Pierre Massat -
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Tee