[LAU] Wah update

Ken Restivo ken at restivo.org
Thu Aug 20 20:21:10 EDT 2009

On Fri, Aug 14, 2009 at 10:19:25PM +0100, Folderol wrote:
> On Fri, 14 Aug 2009 22:43:15 +0200
> Arnold Krille <arnold at arnoldarts.de> wrote:
> > On Friday 14 August 2009 21:59:53 Ken Restivo wrote:
> > > It sounds great. Now I'm either going to hack together an auto-wah via AMS
> > > or something and an envelope follower, or build myself an Arduino pedal
> > > footcontroller.
> > 
> > Get a footcontroller or control it from the keyboards modulation-wheel (if not 
> > used otherwise). Auto-Wah sounds crap.
> > 
> > Arnold
> Nonono
> Building an Arduino footpedal will be much more fun :)
> Hmmm.
> Instead of a pot on one of the analog inputs use a cheap shaft encoder
> and count pulses.

This sounds intriguing. Right now I have an Arduino, and the reason I haven't used it is  because I tried hooking it up to a volume pedal and the noise was so intense it was spewing out MIDI messages constantly... unusable. I had considered rigging up a passive analog LPF, or maybe doing some smoothing in software on the Arduino, but ran out of time/patience.

What would be involved in fitting this kind of encoder to a volume pedal? I can find guitar-style volume pedals easily, and they're cheap. The advantage is that I could use a very cheap ATTiny2313 with no ADC instead of an ATMega Arduino. Encoders sound like the way to go.

> Double Hmmm
> Fix it so that the index pulse is at exactly the halfway point in the
> travel, and it will 'silently' re-calibrate itself every time you pass
> throgh that point.

I don't know what an "index pulse" is. If you could point me to some good introductory reading material on dealing with encoders, I'd find it very interesting indeed.



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