[LAU] audio latency question

[Folderol]

On Sun, 20 Mar 2011 19:11:07 +0000
Folderol <folderol at ukfsn.org> wrote:

> On Sun, 20 Mar 2011 18:52:24 +0000
> andy baxter <andy at earthsong.free-online.co.uk> wrote:
> 
> <snip>
> 
> > The only thing I found problematic in his design wasn't to do with 
> > usability but the expense (and also physical bulk) of having to use a 
> > high end audio interface as part of the electronics. This put me off 
> > building one myself, so I am thinking of having a go at a very similar 
> > design but using a resistive rather than capacitive pressure sensing 
> > technique. I.e. basically the same design but using a sheet of carbon or 
> > metal loaded conductive rubber and measuring the resistance changes when 
> > you scan through the matrix. If this works, it will hopefully produce 
> > similar results but with much simpler electronics and firmware.
> > 
> > andy
> 
> This is vastly overcomplicated. Once you understand the concept itself (which
> really is good), a set of dedicated oscillators and detectors (tuned
> amplifiers+A/D converters) would by much simpler, smaller and reliable. I would
> then be inclined to try to embed the electronics in the device itself, and bump
> up the operating frequency as much a possible to improve the response time of
> the detectors.

Answering my own post...

I mean the original concept using the audio interface is overcomplicated. The
resistive idea has the merit of dramatic simplification but I wonder at the
consistency of the resistive elements and whether you would get a (reasonably)
linear output of if it would tend to behave more like a low quality switch.


-- 
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.