Piezo elements (the round, gold-coloured bell-buzzer type) make excellent triggers. Drumpads like the Roland SPD-n type use these as the triggers. Modifications need to be done to create a reliable trigger. The mechanical integrity of these devices can be a problem: the leads can literally 'fall off'. I 'pot' mine in a layer of epoxy so that the leads are literally glued to the surface. The element can be glued to a rubber pad (this is essentially what Roland does) and mounted on a wooden block to create a trigger pad. Roland uses a small coil in series with the piezo: this is there to provide transient suppression as the instantaneous signal peaks can be quite high (albeit fleeting). This coil is a good idea as it protects the circuitry on the first buffer the piezo sees.
Other Piezo tips (mainly for audio):
- If soldering new leads use a very low wattage iron, low temperature solder and complete the solder joint *quickly*
- buy in bulk as a few will get destroyed as you perfect your method
- if using for audio (i.e., as an audio pickup), then the piezo must be screened. A 'balanced signal' architecture works well here: piezo elements are wired 'signal hot' and 'signal cold', and the hum/RFI suppression is handled by a separate screen.
- The MEAS film-type of piezo work much better for audio than the bell-buzzer type:
http://www.meas-spec.com/product/t_product.aspx?id=2478 5) Impedance, impedance, impedance! Impedance is the rock upon which many piezo hackers perish. These elements need to be presented with an input impedance of many megaOhms. The average line input / mic input is totally inappropriate for these units. I use a simple FET buffer with an input impedance of 10 megaOhms on my piezos. Certain electronic DI boxes will also work well due to their high impedance characteristics, e.g., BSS. If piezos see a low-to-medium impedance, drastic LF rolloffs occur. This is why the cheap guitar contact mics sound so tinny when plugged directly into an amp.
Rich Duckworth
Lecturer in Music Technology
Department of Music
House 5
Trinity College
Dublin 2
Ireland
Tel 353 1 896 1500
It's the most devastating moment in a young mans life, when he quite reasonably says to himself, "I shall never play The Dane!"
--- On Thu, 23/6/11, pd-list-request@iem.at pd-list-request@iem.at wrote:
From: pd-list-request@iem.at pd-list-request@iem.at Subject: Pd-list Digest, Vol 75, Issue 88 To: pd-list@iem.at Date: Thursday, 23 June, 2011, 6:42
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Today's Topics:
1. Re: control lot of audios files with arduino + puredata (FernandoG) 2. Re: Pd performance at TED (Tyler Leavitt) 3. Re: Pd performance at TED (Jonathan Wilkes)
Message: 1 Date: Wed, 22 Jun 2011 21:13:45 -0400 From: FernandoG dataferx@gmail.com Subject: Re: [PD] control lot of audios files with arduino + puredata To: Hans-Christoph Steiner hans@at.or.at Cc: pd-list@iem.at, Martin Peach martin.peach@sympatico.ca Message-ID: BANLkTink3DOLAxTHFsyaFuXvMVxFu+enbA@mail.gmail.com Content-Type: text/plain; charset="iso-8859-1"
Hi guys
I was researching about arduino mega and pd firmata and i found a post where they say that its not posible to use all digital output and analog inputs of arduino mega. http://arduino.cc/forum/index.php?topic=62256.0
I gona buy arduino mega this week, but i need all inputs-output working for my proyect. Do you know something about this incompatibility??
thanks
2011/6/3 FernandoG dataferx@gmail.com
Thanks guys, first i will try the easy way, arduino mega.
best!
2011/6/3 Hans-Christoph Steiner hans@at.or.at
I think people have done some shift register+firmata things, but nothing got integrated into StandardFirmata/ Here's an example:
http://www.makingthingsmove.org/blog/
.hc
On Jun 2, 2011, at 1:02 AM, Martin Peach wrote:
It's certainly possible to make a Pd patch that controls shift registers
through firmata. It's also possible to program the Arduino to do that and send the switch numbers to a Pd patch that has a [comport] in it.
Martin
On 2011-06-01 22:33, FernandoG wrote:
Thanks for answer
Martin: I am researching about shift registers, but if the idea is to use puredata to control audio playbacks, thats means that i need to control shift registers with pd? because the arduino will be flashed with pd firmdata and will be imposible to upload code to control shift registers, is that posible or i am thinking wrong? Thanks again
Best!
2011/5/30 Martin Peach <martin.peach@sympatico.ca mailto:martin.peach@sympatico.ca>
On 2011-05-29 23:20, FernandoG wrote:
Hi i need to design a sistem to control 40 diferents audio files and playback in a stereo sistem. I was thinking to use puredata and arduino, load the 40 audios in a pd patch and use 40 switches and resistors into some arduino inputs to trigger and playback any of the 40 audios in pd. Every switch will be conected to a diferent resistor to generate diferents voltages then arduino inputs can diferenciate witch audio to playback. Also i need to power on a led any time a specific audio is been playback. The 40 audios will not be playback simultanusly, but probably al least 15 or 20 could be.
Anybody knows about a similar proyect? can i use analog input to control various samples or its not good idea? multiplexors? do i need to use an arduino mega or its not necesary?can i power 15-20 led simultaneously? the best way to do this system stable for long long time?
The analog input method is similar to the resistor ladder that analog synthesizer keyboards used. Arduino analog inputs can differentiate 1024 levels but the values of resistors are usually 5%, but 40 levels should be easy. The best way to do LEDs is with shift registers. That way you can use just 3 pins on the Arduino to control as many LEDs as you like. For LEDs use parallel-output shift registers, like the 74HC164. Also the input could be done with parallel-load shift registers (for example the 74HC165), but the resistor method is cheaper. It should be quite stable over time.
Martin
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
"Free software means you control what your computer does. Non-free software means someone else controls that, and to some extent controls you."
- Richard M. Stallman
Ever tried the kind of high voltage piezo you get in cigarette lighters? MaybeY you can drop that across some high value resistors to get an input suitable for an opamp stage. You would need to remove the spring loaded housing. They would be highly robust and able to take a beating from a drummer more directly. a.
On 23 June 2011 at 10:43 richard duckworth richduckworth@yahoo.com wrote:
Piezo elements (the round, gold-coloured bell-buzzer type) make excellent triggers. Drumpads like the Roland SPD-n type use these as the triggers. Modifications need to be done to create a reliable trigger. The mechanical integrity of these devices can be a problem: the leads can literally 'fall off'. I 'pot' mine in a layer of epoxy so that the leads are literally glued to the surface. The element can be glued to a rubber pad (this is essentially what Roland does) and mounted on a wooden block to create a trigger pad. Roland uses a small coil in series with the piezo: this is there to provide transient suppression as the instantaneous signal peaks can be quite high (albeit fleeting). This coil is a good idea as it protects the circuitry on the first buffer the piezo sees.
Other Piezo tips (mainly for audio):
- If soldering new leads use a very low wattage iron, low temperature solder
and complete the solder joint *quickly* 2) buy in bulk as a few will get destroyed as you perfect your method 3) if using for audio (i.e., as an audio pickup), then the piezo must be screened. A 'balanced signal' architecture works well here: piezo elements are wired 'signal hot' and 'signal cold', and the hum/RFI suppression is handled by a separate screen. 4) The MEAS film-type of piezo work much better for audio than the bell-buzzer type: http://www.meas-spec.com/product/t_product.aspx?id=2478 5) Impedance, impedance, impedance! Impedance is the rock upon which many piezo hackers perish. These elements need to be presented with an input impedance of many megaOhms. The average line input / mic input is totally inappropriate for these units. I use a simple FET buffer with an input impedance of 10 megaOhms on my piezos. Certain electronic DI boxes will also work well due to their high impedance characteristics, e.g., BSS. If piezos see a low-to-medium impedance, drastic LF rolloffs occur. This is why the cheap guitar contact mics sound so tinny when plugged directly into an amp.
Rich Duckworth
Lecturer in Music Technology
Department of Music
House 5
Trinity College
Dublin 2
Ireland
Tel 353 1 896 1500
It's the most devastating moment in a young mans life, when he quite reasonably says to himself, "I shall never play The Dane!"
--- On Thu, 23/6/11, pd-list-request@iem.at pd-list-request@iem.at wrote:
From: pd-list-request@iem.at pd-list-request@iem.at Subject: Pd-list Digest, Vol 75, Issue 88 To: pd-list@iem.at Date: Thursday, 23 June, 2011, 6:42
Send Pd-list mailing list submissions to pd-list@iem.at
To subscribe or unsubscribe via the World Wide Web, visit http://lists.puredata.info/listinfo/pd-list or, via email, send a message with subject or body 'help' to pd-list-request@iem.at
You can reach the person managing the list at pd-list-owner@iem.at
When replying, please edit your Subject line so it is more specific than "Re: Contents of Pd-list digest..."
Today's Topics:
1. Re: control lot of audios files with arduino + puredata (FernandoG) 2. Re: Pd performance at TED (Tyler Leavitt) 3. Re: Pd performance at TED (Jonathan Wilkes)
Message: 1 Date: Wed, 22 Jun 2011 21:13:45 -0400 From: FernandoG dataferx@gmail.com Subject: Re: [PD] control lot of audios files with arduino + puredata To: Hans-Christoph Steiner hans@at.or.at Cc: pd-list@iem.at, Martin Peach martin.peach@sympatico.ca Message-ID: BANLkTink3DOLAxTHFsyaFuXvMVxFu+enbA@mail.gmail.com Content-Type: text/plain; charset="iso-8859-1"
Hi guys
I was researching about arduino mega and pd firmata and i found a post where they say that its not posible to use all digital output and analog inputs of arduino mega. http://arduino.cc/forum/index.php?topic=62256.0
I gona buy arduino mega this week, but i need all inputs-output working for my proyect. Do you know something about this incompatibility??
thanks
2011/6/3 FernandoG dataferx@gmail.com
Thanks guys, first i will try the easy way, arduino mega.
best!
2011/6/3 Hans-Christoph Steiner hans@at.or.at
I think people have done some shift register+firmata things, but nothing got integrated into StandardFirmata/ Here's an example:
http://www.makingthingsmove.org/blog/
.hc
On Jun 2, 2011, at 1:02 AM, Martin Peach wrote:
It's certainly possible to make a Pd patch that controls shift registers
through firmata. It's also possible to program the Arduino to do that and send the switch numbers to a Pd patch that has a [comport] in it.
Martin
On 2011-06-01 22:33, FernandoG wrote:
Thanks for answer
Martin: I am researching about shift registers, but if the idea is to use puredata to control audio playbacks, thats means that i need to control shift registers with pd? because the arduino will be flashed with pd firmdata and will be imposible to upload code to control shift registers, is that posible or i am thinking wrong? Thanks again
Best!
2011/5/30 Martin Peach <martin.peach@sympatico.ca mailto:martin.peach@sympatico.ca>
On 2011-05-29 23:20, FernandoG wrote:
Hi i need to design a sistem to control 40 diferents audio files and playback in a stereo sistem. I was thinking to use puredata and arduino, load the 40 audios in a pd patch and use 40 switches and resistors into some arduino inputs to trigger and playback any of the 40 audios in pd. Every switch will be conected to a diferent resistor to generate diferents voltages then arduino inputs can diferenciate witch audio to playback. Also i need to power on a led any time a specific audio is been playback. The 40 audios will not be playback simultanusly, but probably al least 15 or 20 could be.
Anybody knows about a similar proyect? can i use analog input to control various samples or its not good idea? multiplexors? do i need to use an arduino mega or its not necesary?can i power 15-20 led simultaneously? the best way to do this system stable for long long time?
The analog input method is similar to the resistor ladder that analog synthesizer keyboards used. Arduino analog inputs can differentiate 1024 levels but the values of resistors are usually 5%, but 40 levels should be easy. The best way to do LEDs is with shift registers. That way you can use just 3 pins on the Arduino to control as many LEDs as you like. For LEDs use parallel-output shift registers, like the 74HC164. Also the input could be done with parallel-load shift registers (for example the 74HC165), but the resistor method is cheaper. It should be quite stable over time.
Martin
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
"Free software means you control what your computer does. Non-free software means someone else controls that, and to some extent controls you."
- Richard M. Stallman
-
padawan12＠obiwannabe.co.uk -
richard duckworth