Length of cable between potentiometer and axoloti

#1

Hi,I'm thinking about working on a project that would involve 4 hand held controllers all plugged into the axoloti.
Each "game pad" would have a joystick (2 analog signals) and 2 buttons (two digital signals).
I want to make a solid and replaceable system, that could be used in open air fairs, schools, art expos, or even in the street.
I wanted to know if I could use Cat5 cables between the "game pads" and the axoloti ?
And what would be a reasonable length ?
Can the signal be passed along such long thin cables without too much noise, or loss of information ?

Here is a small drawing of the setup idea

axo game.jpg775x672 69.3 KB

I intend to work on this project as an Open Source project and publish the maximum of information about it (and try to work with my local Fablab too), but more than the hardware, I'm really looking forward to making patches for the system, and testing it out with people.

I can imagine quite a few patch configuration using this system, from very experimental stuff, drone patches, and a load of possibilities with sequencers and tables...

I would really like to get a working version out by end of spring to try and test it out this summer, in public.
I think it could be a great gimmick for events, and a new way of doing performances (the main conductor is behind the axoloti, with at least a tempo and volume control (and patch selection buttons), and a midi controller can be added to give him even more control if needed.)
It could be a great project for schools too

#2

I guess it will work, but you'll need custom PCBs, as the CAT5 connectors usually don't fit on prototype board. As for wire length, you'll need to test it…

#3

Looks like a fun project!

Cat5 cable has around 0.094 ohm of resistance per meter, unlikely to make a practical difference at a couple of dozen meter cable length. Radio interference could perhaps cause a noise issue, but a 10nF capacitor at the Axoloti Core connected to gpio input and ground, should suppress that.
And I agree with @janvantomme, those RJ45 connectors are a pain without break-out board or a full custom pcb.

Playing in group can get confusing, getting lost in who's in control of what part of the sound, it may be beneficial to have a separate mini monitor speaker for every player, perhaps even part of the player console. That would lean towards a system topology where every console contains an Axoloti, and the conductor commands are distributed via midi. The conductor console could be some sort of a midi thru box.

#4

I was thinking about using something like these for the connections on the pads and the main box :

For the confusing part of the system, and seperate speakers for each system, I did think about it, but I really want to make this system portable and cheap, and I'm sure with good patch designing, using stereo too (drums and bass on one side, pads and leads on the other, for example...) I could work well.

Otherwise it would be really great to have an AxoControl in everybody's hands, attached by audio and midi (both directions). But that would be an overkill in costs and complexity for the patching (I like being limited to a certain CPU amount, it saves me from getting lost)

I'll give it a try very soon, using RJ45, and I'll see if it seems a good solution (need to buy a new axo board first)
What other easy solution would you recommend, cable wise ?

#5

After looking into components, I thing that doing a custom PCB for the "joypad" would be an smart idea.
it would be easier to fit the joystick the buttons and the rj45 connector, and should be simple enough for me to start working on such a thing (I'm talking PCB's and probably a laser cutout build for the case.
I really need to have a talk with my local fablab... Soon !

#6

Problem with long wires and pots is noise... if there's only slow movements on the pots (human hand is slow for a processor) you can filter the incomming analog value from the pots by puting small capacitor between ground and analog in , close to the axoloti... exemple for arduino :

Try different values for cap and resistor to find a good behavior.
It's also reduce natural electronic and mecanical electric noises from pots....
Hope this help

(Et bonjour de Bordeaux, j'attends mon premier axoloti, je vois que t'as déjà bien mis les mains dedans... je risque de revenir vers toi...)