Korg SyncKontrol /Iphone headphone out to Gpio

#1

I want to try feeding my Axoloti a Clock via the Korg SyncKontrol app to some digital Gpio In.

Acording to this site output voltage is less than 3v, so can I assume this would be a safe thing to do?
http://www.kenrockwell.com/apple/iphone-5/audio-quality.htm

This would be a quite convenient way to have tap tempo, BPM Display and Ableton Link.

#2

headphone is ac, so I think you have to take to analog in, id probably use an opamp to scale it into 0..3.3v range.

#3

Ok but it's not risky to just try then?

I recorded a volca sync tick once, it doesnt go below 0 so maybe I wouldn't need scaling. (I could try to record one of the sync ticks before too)

Edit: Goes a little bit below 0 maybe.

#4

You could use a diode clamp to ensure it doesn't go below 0 or above 3.3v