I’m looking to build a pedal for my synth that outputs 8 volts when pushed. I’ll use it to generate gates and triggers on the (eurorack) synth. Does anyone have ideas about how to approach this?
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Suitable switch and voltage divider? Do you need debouncing?
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Thanks! I should say that I’m a complete newbie at this. Searching for “switch and voltage divider” is turning up lots of useful results 
I think that can be handled on the synth. I’m generating triggers on the synth from audio signals now. Debouncing the output from the pedal can probably work in a similar way.
I’m playing on the synth tonight and am running out of hands. Another pedal that would be great would be something that functions like an expression pedal, but outputs 0 to 8 volts. That seems like a more complex project than the on/off 0 to 8 volt pedal.
An expression pedal is just a potentiometer, acting as a variable voltage divider. I’d say the mechanical construction (for any pedal) is probably a bigger challenge than the electronics.
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Old Games console car pedal 
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Which Makes me think I should salvage the one that’s in the pile to go to the tip…
Rob
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For me, a circuit with a 9v battery, jack socket and a reed switch on a thin board the width of your foot. Place a magnet on the floor, a washing up sponge on the magnet and the board with the reed goes on top. Ugliest gate in the world but the mechanics are simple. Squash the sponge.
If you want some simple variable resistance: cut a wide slit in a tennis ball and put an LDR inside with a cable connected to power and a jack or straight into the module. Tennis ball on floor (best place) , then shine a bright torch or a desk lamp at it. As you step on the ball, the slit opens and the LDR does it’s thing.
As Sam says, don’t be scared to try it!
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I think @fredrik nailed this one-the mechanics will be the issue. I do have one thought though-you could get (or make) a force-sensitive resistor and then use it with another resistor for the original voltage divider idea. It would be less of a pedal and more of a weight-sensitive strip, but it would serve the purpose of changing an output voltage when you stepped on it.
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This might be it, but it works. I’m not sure I’ve got the correct resistor on there, or if I even need a resistor - sending 9 volts to the eurorack is fine.
The next step is to figure out how to get it into a pedal. I’ve got an old expression pedal that seems like it should be able to trigger a switch. Possibly the lever in it could be connected to a reed switch.
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Yup, that things perty ugly. Who cares if it works though! I think its cute.
I got a bigger button and put it all in a cardboard box. It works well as a foot pedal. I can play piano with both hands and trigger a looper with my foot. That was the problem I ran into the other day that started this.
I need a few of these. I’ll try using an old guitar pedal for the next one. The expression pedal I was thinking about using would be too slow for sending triggers.
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Nice-Sparkfun style! (Just remember, when you do step on it, it is only cardboard.)
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