[sdiy] Synth Keybards and Number of Keys

[John Luciani]

On 3/1/07, Edward King <edwardcking2001 at yahoo.co.uk> wrote:
>
> I am building a couple of two octave pedal boards that use slotted
> optical switches
> (PCBs arrive tomorrow!). I am thinking of doing some keyboards that use
> slotted
> optos in an analog mode.
>
>
> -- if you encounter any problems, let me know and I'll do what I can to
> help.
>
> -- Conversely, I would like to build pedalboards, so perhaps you can share
> your stuff with me too!

I purchased a couple of Wersi pedal boards that were surplus (although
it wouldn't
be hard to build these from scratch). On the back of the pedal boards
there are a spots
for four circuit boards. Each circuit board monitors a group of either five,
six or seven pedals. The boards are designed with jumpers so that they can be
cut. Readback is done using four 8 bit parallel to serial latches (one
per board).
The boards are daisychained and a single header 4x2 header connects to a
uC board.

There is a fair amount of side-to-side slop in the pedals. Probably too much for
the slot size of the opto. I am probably going to use some steel dowel pins
underneath the pedals to remove the slop.

(* jcl *)

-- 
http://www.luciani.org