Positional Sensing Snare

[philfine]

Hello everyone,

I am wondering if there is any way of achieving positional sensing using Trigger IO and some remapping software.

What I mean is: roland is capable to produce positional information based on analyzing the wave form from the piezo as can be seen from there patent fill.
They deduce it based on the frequency of the first half wave produced in a hit.

If we can somehow recompute that same information to a regular piezo. I interpret the signal an reproduce a valid signal that could be interpreted by Trigger IO then a software could read that trigger info and reproduce a CC message to set the sensing position.

What do you think ?

Thanks

[BarT]

Wouldn't the software have to be in or before the Trigger iO? Doesn't sound feasible to me.

Bruce

[Guest]

Wouldn't the software have to be in or before the Trigger iO?

Yes it would.

Doesn't sound feasible to me.

Bruce

I would have to agree. If Alesis tried to put it (Positional Sensing) in the Trigger I/O, they would most likely have a patent lawsuit on there hands. This is because, I believe, Roland holds a patent to that technology as well.

[philfine]

Best to describe the idea with a drawing



As you can see in the diagram the center piezo would connect both directly to IO and small circuit that would convert the positioning info into a valid IO input piezo signal.

The midi mapper would take both Notes comming from IO and convert it into a CC message which is what is expected by SD2 and BFD2.

Comment please

[BarT]

But even if you could design the small circuit for that signal converter box, you would be limited to on/off positional info (e.g. outer or inner) due to the extra iO input and single note number, instead of the 0-127 which a TD-12/20 will transmit for CC 16/17/18.

Bruce

[philfine]

But even if you could design the small circuit for that signal converter box, you would be limited to on/off positional info (e.g. outer or inner) due to the extra iO input and single note number, instead of the 0-127 which a TD-12/20 will transmit for CC 16/17/18.

Bruce

I guess I didn't understand why I would be limited ...
The signal coming out of the circuit would contain just position info.
In this note 0 cold mean center and 127 edge.

The signal going directly to the IO would provide sensibility.
For this 0 means soft 127 means hard.

Hope I was able to explain. ;-)

[BarT]

Yep, I guess that's theoretically possible. Good luck designing a circuit which converts positional waveform to velocity, and software to convert velocity to control change, without introducing too much latency.

Bruce

[philfine]

I am not saying that it is not totally stupid to approach position sensing in this way ... in fact I wanted to discuss mostly the teorectical part before starting to jump how to do it.

Maybe it would be a lot better to implement it in a edrum module such as megadrum instead of having all this tricks.

Anyway I don't see how can it be such a delay to actually convert a note into a CC message. I guess the current Hihat maps should take a lot more cycles then this.

Since I do not have such a great design knowledge on electronics I cannot speak much and discuss how hard it would be to make that BOX :-S

Anyway I am just interested in being able to have a position sensitive snare without having to spend thousands of dollars.

If anyone is interested maybe you can give your feedback and how knows make it possible.

[philfine]

Hello again,

What about connecting a piezo directly to line-in in sound card to have samplings of the piezo and get both sensitivity and position sensing from piezo signal and generate midi messages from it.

Do you think line-in port in sound cards can sample enough the signal to actually detect at least for a few levels.

Please comment ...

[racer52]

a question about TD20 Positional sensing

Just read this thread - wonder if you guys know the answer to this operational question.

I have a td20. just discovered drum instrument #560 'For Pad Check'

It seems to be designed to help check positional sensing on a pad. I assigned it to my snare drum and can hear 4 different note/pitch sounds as I tap the drum pad from edge toward center.

My question is: How many different notes should I hear if my pad is working at the best possible positional sensing?

How should I use 'Drum Instrument #560 For Pad Check' to its best functionality?

Thanks- racer52

[Michael Render]

I wrote a program for the PC that reads a drum strike via the audio input. You can then do anything you wish with the waveform. Thankfully, the incoming wave shape is not too complicated. It is my understanding that PS is a function of frequency and volume difference. I wouldn't want to reinvent that, it seems like a lot of trial and error.

[BarT]

Just read this thread - wonder if you guys know the answer to this operational question.

I have a td20. just discovered drum instrument #560 'For Pad Check'

It seems to be designed to help check positional sensing on a pad. I assigned it to my snare drum and can hear 4 different note/pitch sounds as I tap the drum pad from edge toward center.

My question is: How many different notes should I hear if my pad is working at the best possible positional sensing?

How should I use 'Drum Instrument #560 For Pad Check' to its best functionality?

Thanks- racer52

I don't think 560 For PadCheck has anything to do with positional sensing; it just monitors strike velocity. You can switch off positional sensing (at SETUP, MIDI, CTRL) and still get the eight tones corresponding to velocity levels. It is more difficult to get the higher levels of velocity the further the strike is from the center though.

Bruce

[racer52]

Thanks Bart.
Man, I tell you, I have barked up so many wrong trees that if I were a coon dog, my owner would have shot me by now!

[philfine]

I wrote a program for the PC that reads a drum strike via the audio input. You can then do anything you wish with the waveform. Thankfully, the incoming wave shape is not too complicated. It is my understanding that PS is a function of frequency and volume difference. I wouldn't want to reinvent that, it seems like a lot of trial and error.

Cool ... :-)

Can you either open a project in some GIT server or share the code.
Or can you share the current code ?
What I would like to see is a open source remapping software to which we could include something like this.

I guess It is possible to be done ... the question is how much of delay can we expect in it, and if it would be noticeable.

Thanks a lot

[yeahtuna]

What about connecting a piezo directly to line-in in sound card to have samplings of the piezo and get both sensitivity and position sensing from piezo signal and generate midi messages from it.

Do you think line-in port in sound cards can sample enough the signal to actually detect at least for a few levels.

If it's preamped, definately...using the line in, maybe--those piezo signals are pretty hot--I'll have to give it a try

Anyways, I'm made a VST that does exactly what you're talking about.

From a single piezo mess drum, it detects velocity sensitive hits with positional values 0-127 as well as being able to differentiate between regular hits and side stick. It's self calibrating to boot!

The only issue is that there's a 13 millisecond latency that I can't erase unless I figure out how to host the drum sampler inside my plugin---that's gonna take a bit more work.