Connecting a pedal to the Axoloti

#1

Hey Axoloti Community,

I need some help figuring out how to solve a certain problem.

I want to connect a pedal to the Axoloti in order to trigger FX/sounds. However I don't have a MIDI keyboard connected to that axoloti and want as little additional hardware as possible. So the finished product should be only the Axoloti and some kind of cheap guitar patch switching pedal connected to it at best. I've been thinking about that for days but cannot come up with a solution that doesn't cost a hundred bugs.

I'd be grateful for your thoughts!

Cheers

Alex

#2

Do you have a pedal already that you want to connect?

Most pedals, as far as I know, are either an on-off switch, or a potentiometer. Either of those is easy to hook up to axolotis I/O pins directly. It will require soldering some wires on the Axoloti, and connect them to a jack socket, but it's easy work.

If you can share what kind of pedal you have in mind, I can probably give some instructions how to wire it up.

#3

The connection diagrams can be found here:

Either the "Switch" or the "Potentiometer" schematic applies, depending on the type of pedal. What remains is to figure out how the jack is connected internally to the potentiometer.

#4

Thank you for your quick reply. For starters I've got a M-Audio SP-1 Sustain Pedal. Though I have no experience in soldering anything I'd be interested to know how it would theoretically be done.

#5

I worked on connecting the foot pedal of my old Behringer V-Amp this afternoon. The only thing you need to solder to the Axoloti is a Neutrik stereo jack input. You can get these for around €1.

Photo over here:

Connections:
Sleeve to VDD
Ring to PB7
Tip to PB6

The patch uses to gpio/in/digital objects, mode needs to be set to pulldown.

behringer-vamp-testpatch.png1260x818 50.7 KB

#6

Hi there,

I need to connect a moog ep-3 pedal to the axoloti

This is a pot type of pedal, and I understand I need to connect VDDC GND and PB1, as in this image

I'd rather NOT open the pedal in order to see how is the jack connected to the pedal/pot's pins.

So my question is: Can this be done without opening the pedal?

For example, I have a cable that came with the pedal which I understand is simply a stereo jack cable. I haven't looked at the soldering but, can I assume the ground, longer part of the plug is connected to the pot's ground, and the other two should be either VDD or GPIO ?

Can I discover those two by trial and error? Or do I risk frying the pedal or the axoloti?

Could I actually do trial and error for all three cables ?

/EDIT
I found a random source saying that "The Moog EP is powered from the ring and uses the sleeve as the ground."

So I would try that first, but just in case I still would like to know if something can go wrong by connecting it wrong.
EDIT/

Thank you very much

#7

do you have a multimeter? if so, measure the resistance between the different points on the cable when you press the pedal down and see how they change, this will tell you what to connect where...

#8

Thank you. It is as the random source said:

shield -> sleeve, to Axoloti GND
red -> tip, to axoloti PB1
white -> ring, to axolotu VDDC

I have the pedal on OTHER polarity but not sure that really matters

I am reading the values with the GPIO object using the PB1 in

Thanks again