Hardware Analogue Controllers

#1

Hi,
I'm really new to this, and I plan to buy a Axoloti or 2 in the very near future, I am really wanting to know is there anyway to use around 30ish knobs/sliders/switches without having to design a new add on circuit for the axoloti? I really am a newbie to circuit building and fear I could really wreck the Axoloti, any helpful hints/pointers/how to guides would be most welcome, I plan on creating a clone of a couple synths I've always loved for personal use but both require more hardware control than the Axoloti's inputs seem to allow.
Thanks in advance.
p.s.
This seems like a wonderful idea for people like myself who cannot afford to buy over inflated classic synths which might break down anyway.

#2

I doubt you'll get those numbers without learning some basic easy electronic theory so that you understand how to 'multiplex' signals and use less gpio. I'm also new to the Axoloti and so far have only one :blush: -( It is an awesome inspiring synth core.

#3

oh well, I really was hoping for an easy fix hahahahahahahahaha.
I seem to remember someone say it was possible to use more by adding some resisters inline but I could be wrong.

#4

I suggest realizing your machine, so to speak. draft it up and go from there... always referencing the axolti gpio. You can use resistors, or get a chip that muxes them... but that may be more dependent on your #1 goal.

#5

A MIDI controller would probably be the simplest quickest way to do that.

#6

I think you need a clearer understanding of what knobs, sliders and switches you intend to use.
Sliders - I expect this would be a sliding potentiometer, if it is, to get your reading from the slider, each slider requires an analogue input. If there are not enough, they can be multiplexed, there is some objects in the community library on this.
Knobs - I see this in 2 categories, a rotational potentiometer, in that case same rules apply as per the slider, or rotary encoder which uses fast digital switching techniques to change values.
Switches - They can use any GPIO input to regester switching, but one thing you can do which is where I think your reference to resistors comes in, you can chain many switches togther seperated by a resistor each, connect to one analogue input, and there you will have many switches using only one pin.

Which ever way you choose, if connecting dirtectly to the Axo, you will need the supporting objects etc. This is very doable depending on your needs.

The other option which can free up Axo resources is to build your own Midi controller with an Arduino or something else, using very similar approach you would with the Axo, but instead sending exact Midi outcome to the Axo for control.

There are lots options, everyons needs are different, took me 12 months to come up with a design I wanted, and even after that it has morphed even further.

Have a good look at some of the other projects and video's, get some clearer ideas, how many knobs, how many slidder and switches etc, what do you want them to do.
:grin:

#7

You chaps have been amazing in your help and ideas, the couple of synths I want to clone are the jupiter 4 and the polymoog 280a its really the jupiter 4 which will cause the problems as that has the most sliders/switches etc.
As soon as I heard of Axoloti, I was curious as to what was possible, having watched videos etc I realised that I could recreate my beloved synths. :slight_smile: thank you very much people you have offered much food for thought.