MIDI: how to trigger events with piezos/switches – notes and CC

[dpe]

Hi!

This is first post here and I'm brandnew to Axoloti.
My question is about a pretty basic topic: MIDI.

I'm planning the following setup and would like to know if this is possible with Axoloti. I have some piezos and switches that should trigger events via MIDI using my sampler (octatrack). For now I'm using a Alesis Trigger i o, but this unit can only send MIDI notes, no CCs. But as I want to controll triggering samples as well as adjust parameters of effects, I do need MIDI CCs. I would like to use different piezos (the ATio has 10 inputs) and it would be great to map several events to one event.

So here is the question:
1 – Can I connect piezos and switches to the Axolotiboard and receive notes as well as CC-values depending on the velocity of the signal? If yes, how complicated is this to build the patch or are there even examples out there?
2 – Or do I have to send the notes coming from Alesis Trigger i o to the Axoloti for processing them into CCs (in this case Axoloti would only be a processor)?

here you can see a screenshot, showing the MIDI for octatrack:

Please let me know if there are topics or links regarding this question. I would really like to use just the Axoloti for this, as it is super portable and affordable as well as flexible for future projects. I'm super excited about your answers, thanks for that.

best

[Blindsmyth]

I think you could hook up the piezo's to axoloti's gpio, people already tried/exchanged idea's about this here, just use the search engine. I think it would involve building some analog input circuit for the piezos.
As a start you could hook up 2 piezos to the audio inputs and convert them to trigger, and then expand using the gpio.

Converting midi notes to the right CCs is super easy with axoloti and could be a great way to start patching with axoloti.

So I'd say just get one and start experimenting

[Gavin]

You should also be able to hook up the piezo directly to an Analogue input on the Axo, but you need to wire up a resistor in parallel, I think 1meg is what they use, then you just map your objects to different events depending on the analogue input level received. Similar to how you would read the values from a connected potentiometer.

[dpe]

thank you for the anwers.

I haven't worked with code or electronic components like resistors before, would you still recommend in doing it by myself? Another way of doing it would be using the Alesis Trigger i o and sending the MIDI notes to a MIDI event processor + (which can be mapped with a software).

Could you name tutorials or books/ sites where I can find information about doing first steps within this territory?

[janvantomme]

The basics of connecting electronics to the Axoloti are covered in my book. (Shameless plug…)

Getting Started with Axoloti, the Book

Since the community is very new, and there aren't a lot of resources available to get started with patching, I've decided to write a book about Axoloti. The book will teach you how to create basic synthesizers, drum machines and audio effects. These are the chapters I've planned. The first chapter is available as a free sample. Chapter 1: Creating Your First Synthesizer Chapter 2: Creating a Polyphonic Synthesizer Chapter 3: Diving into Sound Design Chapter 4: Creating Drum Machines Chapte…

[johannes]

A small custom object can re-route incoming midi note-on events to midi CC events, attached here.
However using something like drum triggers are sensitive to double detections, the last velocity will overwrite the (perhaps more significant) previous velocity, most extreme when playing midi drum triggers with brushes...
note_to_cc.axp (1.3 KB)

[dpe]

thanks for that. While trying to open it I get the response that the file was written with a newer version 1.0.12 – how to proceed, as I can only find 1.0.11 on github?

And I want to add that I won't use it in a drummer context, much more it is based in an art-installation setting. Important for me is to know if it is possible to connect several piezo to the board and when triggered, that the notes are processed to CC events. I think both got confirmed from the community.

I'm just a bit afraid that I need coding skills as well as electronic knowledge to get this stuff working, instead of using the Alesis Trigger i o and EventProcessor +. But Axoloti seems the creative solution for future projects and is much cheaper. Well, I guess I have to try – but every hint is appreciated!

thanks

[johannes]

Sorry, updated the attachment above for 1.0.11, version 1.0.12 is indeed not released yet.

[Blindsmyth]

If you have the trigger Io already I'd say use it. Then you have something that will work relatively simple wich is a great starting point

Then you can still expand the project by hooking up the piezos directly to the analog inputs, or experiment with different kind of sensor to get results you would have never expected

[boBK7IQ]

I was looking at chapter 1 of the book and the first thing it says is to click on new project.
I did not see an explanation of what program this is, where to get it or how to connect up
the Axoloti to the computer or what format we are working in.

You might want to create a page of requirements and basics of the tools or even the name of the tool
being used in the book. Or maybe a link to the software and hardware guidlines and simple block diagram
of the system ?
boB