[PD] Sensors

[Marc Lavallée]

On Fri, Oct 31, 2003 at 02:29:54PM +0000, matthew jones wrote:
> I really don't understand why people are so hooked up on using MIDI or
> serial/parallel ports for interfacing sensors with pd.  It strikes me
> that the absolute best way if you are at all worried about sample
> rate/quantisation amount is to use the audio signal inputs of your
> soundcard.  some simple circuitry and then you have maybe a 96kHz 24bit
> input - super fast control and with same latency!
>
> am I mistaken? has anyone used this to good effect?  I was thinking 
that
> the terminatorX style turntable things are a prime example of where a
> mouse just doesn't offer enough resolution to do even a half decent
> job....

There's many ways to interface sensors. Using an audio card is definitely
possible, but it's not a silver bullet. Many audio cards cannot be used
an input interfaces, often because the input stages are expecting audio
signals and nothing else.

Here's a good example of using an audio input as an interface input:
http://www.inf.ethz.ch/~mringwal/lirc/
This PDF explains that some audio cards are using a DSP to filter the
input signals:
http://www.minidisc.org/contrib/oded_files/AudioCardIRSampler.pdf

I'll try this audio input lirc interface, and see if the idea could be
extended to other interface circuits.
--
Marc