These photos were taken right before I finished wiring up and
programming the claytroller for the "How to Make Almost
Anything" class presentation.  In the picture on the right,
the claytroller is surrounded by the versions of Scratch Patches I
developed for this project. 

I
came up with the idea for Scratch patches after I explored ways to
connect multiple circuit boards (that serve different functions). 

The Scratch Patch schematic on the left is the design for a patch
that communicates with computers serial ports through it's left side -
voltage/ground/data-line are routed to the right side to listen to all
Scratch Patches connected to it. 

The Scratch Patch schematic in the middle is the design for a
simple patch that routes the voltage/ground/data lines straight across
the board - stopping through 4 pushbuttons, 1 pull-up resistor, and 1
ATtiny15L microprocessor along the way (far right photo). 

The insides of the claytroller uses two-layers of Scratch Patches. 
The patches used are (from left going clockwise) a "thick"
(1/4")/straght-through/button patch, a communicator patch, a
button patch, a filler patch, and an extender patch.  The filler patch
is placed under the 4-button patch.  The extender patch takes the
voltage/ground/data lines from the communicator patch is sits
underneath and routes it to the thick/button patch (that occupies both
layers). 

Patches without surface mount electronic components soldered onto
them can serve as connectors - both by connecting on the sides or by
stacking (thanks to the voltage/ground/data lines that wrap around
under each patch).  A photo of 1/4" and 1/8" patches is on
the right. 

[a photo will be here at some point]

The Claytroller's two button patches are (almost) programmed to be
polite when sending their pressed-button status to the
communicator patch - that in turn sends the button status to whatever
piece of software it's programmed to speak to.  The Claytroller was
programmed to send button press events to the Scratch
programming environment my research group is developing.