Ben + UBB + a few components = "VGA"

Werner Almesberger werner at
Fri Apr 29 10:01:07 EDT 2011

Kristoffer Ericson wrote:
> I assume only on exist so far?

I've made only one version 2 board so far.

> Whats the price for parts

For the current version 2 board, you need:

- one UBB

  but I would recommend getting a few, in case something goes wrong,
  if there's a design change in the future, or for some new project:

- half a male VGA monitor cable (a male-male PC-to-monitor cable yields
  two such half-cables, a male-female VGA extension cable would yield

  Pretty much any PC shop should have them. They're not very expensive.
  Here's one for USD 5:

  The bead is already overkill ;-)

- resistors:

  3 x 82 Ohm
  1 x 330 Ohm
  3 x 470 Ohm
  3 x 1 kOhm

  I used the 1/8-1/4 W axial through-hole type with a body length of
  about 3.2-3.4 mm, 5% tolerance. Here's an example:

Making a cable-board combo shouldn't take more than 1-2 hours. Most
of the work is sorting out the VGA signals.

Regarding the choice of components, I picked through-hole to have
reasonably large and mechanically solid contacts to which to solder
the VGA cable:

You could also mix SMT and through-hole, like I did in version 1:

In version 1, I used a ribbon cable to connect to a VGA connector:

- easier to keep track of what wire goes where
- less mechanical strain on the UBB side

- mechanically fragile
- risk of accidental shorts

Note that the connection in the image only has two ground connections,
because most of the grounds are joined somewhere in the VGA cable. The
version 2 board connects all six grounds (R, G, B, Hsync, Vsync, and

> or where can one buy it?

I haven't figured out a good way to productize it yet. It would be easy
enough to make a UBB-like board with SMT components and proper contact
pads for VGA, but you'd still have to solder the VGA cable, which is
messy work. Such a board could be tightly attached to the VGA cable

Alternatively, one could make a two-board combo with plain UBB plus a
VGA daughterboard that uses a PCB connector. This would be easier to
make but would lack the tidiness of an integrated solution.

Another consideration would be how to connect to something that isn't
directly a monitor, e.g., a device with a special connector or a cable
that goes off to more distant equipment. The two-board approach would
have a female VGA connector and would just use whatever cable is
already available. The integrated approach would need a gender changer,
like this:

- Werner

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