GPIO outs used to trigger analog drum modules.

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princessdan
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Joined: Sun Sep 18, 2016 8:00 am

GPIO outs used to trigger analog drum modules.

Post by princessdan »

Anybody out there maybe already figured out how to do this, I hope? Commercial drum modules are designed, generally, to be driven by the voltage from a piezo, which can generate up to 5v, but I'm hoping to get a 3.2v signal to trigger things. Otherwise, I need to buffer the signal up to 5v. And I could use some advice on which modules would best drive the GPIO module, or how to finesse the hexadecimal values in the pattern section. I need to get a 3.2v signal that acts like smacking a piezo with a drumstick. I've gotten far enough with sunvox to get midi in/out working, so syncing to my MPC should work. I want to trigger several objects that are pre-midi, pattern synced to the MPC, all simultaneously, including a drum-x unit and casiotone super-drums era stuff. There's this one crazy German eurorack module manufacturer, MFB I think, make a module that does something kind of like this, but with much more limited functionality than what sunvox/pi 3/GPIO *should hopefully* be able to do.....and the eurorack thingy costs €330 with no housing or power supply.
princessdan
Posts: 7
Joined: Sun Sep 18, 2016 8:00 am

Re: GPIO outs used to trigger analog drum modules.

Post by princessdan »

By the way if it matters pi 3 B running raspbian with the library all updated so GPIO *should* be enabled at the OS level already.
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NightRadio
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Re: GPIO outs used to trigger analog drum modules.

Post by NightRadio »

I will try to make something like this, and provide the circuit diagram + video here
princessdan
Posts: 7
Joined: Sun Sep 18, 2016 8:00 am

Re: GPIO outs used to trigger analog drum modules.

Post by princessdan »

You are seriously my favorite dev ever.
princessdan
Posts: 7
Joined: Sun Sep 18, 2016 8:00 am

Re: GPIO outs used to trigger analog drum modules.

Post by princessdan »

I just loaded up the pi GPIO example that was bundled with the sunvox download, and it just works right off the GPIO pins.
3.2V is enough to trigger a Pearl Drum-X brain, wired straight to a 1/4" cable. No buffering, resistors, or schematic needed. I just had to turn up the volume on the "drum synth" and "LED level" modules a bit, otherwise it *just works*
Trigger a drum hit in the drum synth module, drum hit happens on the Drum X every single time. Will have to fiddle with more settings to get the latency down as much as possible, but I couldn't be happier with where I'm at already.
princessdan
Posts: 7
Joined: Sun Sep 18, 2016 8:00 am

Re: GPIO outs used to trigger analog drum modules.

Post by princessdan »

By the way, I updated to the *brand new* Jessie with bundled chromium OS for the PI3 before I got this working, which may or may not matter.
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