Arduino - expression pedal mono (TS) jack?


I’ve made easily an expression pedal input with this tutorial :
It works perfectly for TRS expression pedals !

But I would like to use my Ernie Ball VP (like I use to with my timefactor, even my line6 DL4 years ago), so I thought about making a voltage divider and reading the A0 input and calculate the ErnieBall resistor with simple math. I can’t see how should I modify the code to make the arduino make this math, does anyone could help ?

My Ernie ball has a 25kohm pot, so I’ve put a 22kohm resistor between the ground and the tip-jack… I may be wrong there too ?
The modified build :

  • +5v adriono → sleeve jack
  • ground → 22kohm resistor → tip-jack
  • tip jack → A0 input of the Arduino duo



Does the pedal at least “move something” when you connect it to the converter?
If yes, this is a bit more Arduino coding than anything else :grin: I can try to give you some help though :wink:

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Try this


No, nothing happens when I use a TS jack… Thanks for proposing help !

oh ! Of course !!! I completely forgot about this, I’ll use that solution, thanks !

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I’m back testing the tutorial, and the Arduino duo restart when I plug or unplug the TRS jack. Doing this is making a short-circuit between 5V and the ground no ?
Is there a way to avoid this ?
Have I done something wrong ?

Most likely yes.

Have you any cables voltage and ground cables possibly touching each other in a conductive spot?
Do you have it properly wired on the TS or TRS connector?

Thanks for the help Jon, I’ll check all this ! next week !

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You’re welcome :slight_smile: Please let us know about your findings :wink:

Try to plug all connectors before powering up the Arduino and Mod.

Sometimes the 1/4 jack plug sleeve or ring momentarily touches 2 contacts in the jack while being inserted.

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