Sandy, get at least 8 switches, 10 will give you 2 spares in case you drop the
unit and rip off a lever. I am now recommending 30 to 50 gf switches, 16 is too
light. Get "simulated roller" arms if you can.

The switches wire to the B port bits 0-7 with odd numbered bits distal and more
significant bits toward the pinky. Thus bit 0 is the proximal index finger
switch, bit 3 is the distal middle finger switch, 7 is for the distal pinky.
I'm speaking here of the bits in the input byte, not the pin numbers of the
header. The chip does have internal pull-ups; closed switches pull down to
common ground so ignore the Vcc pin.

You're right the switches parallel the joystick on port B. If you move the
joystick with my hex file installed you get letters on the screen. I don't
remember why I did that. Maybe it was something about the physical location of
the B port pads. It seems dumb now.

You can also ignore the board's power jack --- the board runs off the USB port's
power.
=================

--- In chordite@yahoogroups.com, "sandyroman@..." <sandyroman@...> wrote
...
> It would seem some 7 switches, and a ribbon cable (and maybe a
> pin & socket header pair in the middle of the ribbon cable),
> that is enough.
>
> For software it is all free with the AT90USBKEY package,
> or downloadable from Atmel, and load John's Hex file...
>
> You buy the board, wire the switches to it and then use the
> free Atmel Flex programmer to program it. It's a slam dunk.
>
> which will be clear once I have the AT90' plugged into the port.
>
> So, if the above is all true, how does one wire any and all
> accessories?
>
> In the Hardware User's Guide schematic, Jack 6 has as inputs:
> Pin 1 = Vcc
> Pin 2 - Gnd
> Pin 3-10 are inputs (7->0).
>
> Also shown is the Joystick interface which uses Port B 5,6,7
> and Port E 4,5.
>
> Minor point: so we can't use the joystick here as that
> leaves only 5 inputs available.
>
> Having figured that out, How are the switches wired?
> (There are 7, among 4 fingers, and distal and proximal placement. )
> I am assuming we have a common connection (either +Vcc or ground)
> among them and pull them High or Low via switch closure.
>
> Given the Joystick configuration, I bet they get pulled to ground
> via the switches, and have pullup resistors (or current sources)
> that are already part of the AT90.
>
> Then which switch goes to which pin on Jack 6? (Or to which
> port of port B?)
>
>
> I can't seem to find the Marquardt 6450(?) switches in less
> than quantities of 24. Anybody have an idea?
>
> The other switches are findable in small quantity I suspect.
>
> The tiny 0.050 pin spacing seems tough to find a header for,
> at lesat in small quantities. A shame. I saw the AVR
> discussion about them. Seems to have petered out.
>
> Thanks,
> -Sandy
>