roland's d-beam...?

[Andy Sloane]

On Tue, Sep 21, 1999 at 08:50:03AM +0200, dpm wrote:
> hi
> i've been reserching building my own optical midi controller (it uses
> light and shadow) for about a week, and i'll tell you what i've come up
> with. 
[...]
> so... paia (www.paia.com) sells a diy kit "midi fader" that uses any
> potentiometer for pitch wheel or controller messages for $87. but then we
> need different interface circuitry between the photo cell and the kit.
> this is about the point to where i've gotten and need help with this
> one.... 

$87?  That seems kinda steep.  I built a MIDI knob box and the most
expensive thing was the "console"-style enclosure (which was $16 at radio
shack).  Basically, the circuit is a PIC16F84 (~$6.50) connected to a
10-port analog-multiplexing serial ADC: ADC0832 (~$2?).  The ports are just
wired to pots.  I haven't gotten around to putting the schematic/code up on
the net, but I will some day.

As far as your optical elements, are you using photocells that generate a
voltage, or CdS light-sensing variable resistors?  I'd think the latter
would be cheaper and apply more directly.

> http://www.audiomulch.com/midipic/

This looks like a pretty good site.  a lot of the MIDI projects use basic
stamps though and those are pretty expensive.

-Andy.