Accelerometer-controlled Guitar Effects

Question

Hi there,

I wanted to share this with the community in case it is helpful.

Link to the preset here:

http://mididesigner.com/qa/?qa=blob&qa_blobid=2953948448792356830

I happen to own an iON Guitar (pictured below). It may look like a toy :) and certainly the companion app is quite limited, but the cool thing is that it can be used to control any MIDI iOS music app, like GarageBand, Nave, etc And then you can process the sound via AudioBus or IAA using apps like AmpliTube or Ampkit.

 

To top it up, I used MIDI Designer to control AmpliTube's "Cry Baby" Wah effect with the inclination of the guitar. All it takes is a slider control tracking the accelerometer and sending a MIDI CC message (I am using CC 11 in case I want to switch with a physical expression pedal, but you can replace as needed).

 

 

The complication I faced was that the accelerometer is tracking the whole axis (from

vertical to inverted vertical position) so the horizontal position sends MIDI value 64, while I would like "0" to be the horizontal position (normal playing stance) and "127" to be the vertical position (guitar fully raised), that is, only half of the current range. Thanks to Dan's amazing support I used 256 Named Ticks, set 128 of them to "0" and the rest to values 0 to 127.

 

With the learnings I created the preset attached that can be used to toggle and accelerometer-control 2 different effects via MIDI. Note that you have to keep MIDI Designer in the foreground. If you push the app to the background still works but the accelerometer's refresh rate is too slow to be usable. Maybe the community knows a workaround?

 

 

My setup, aside of MIDI Designer, consists of iON Guitar (MIDI controller) - GarageBand (IAA Host) - Alchemy (IAA Instrument with Electric Guitar samples) - AmpliTube (IAA Effect with MIDI mapped Wah).

 

However, I image the same would work with an iPhone strapped to a real guitar processing acoustic audio via AmpliTube directly. Also, the preset could be extended with more toggles and knobs for controlling other effects, etc. The sky is the limit! :)

Comments

Thanks, this is awesome. We're at NAMM right now but we'll share about this awesome thing (and have time to process and read it) in a bit. Looks AWESOME at first glance, thanks for sharing!

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Just shared this today via FB and Twitter: nice work!

Note: in 1.6.2 (forthcoming) you'll get backgrounding in MD for up to one hour, which should work for this concern. Thanks again!