Denny Esterline wrote:
>> Peculiar, not sure if it's just me or if others see it too, but my
>> last post returned to me as an attachment... Hmm, let's try again.

I got an empty message from you, so it probably did have the text as an
attachment.  This time the message came thru fine, but when I did a reply I
got two levels of quoting (>>) as you can see above instead of one.
Strange.

>> Personally I don't like the look of traces at random angles, and it
>> can lead to uncertainties for high frequency work.

The electrons don't care.  For high frequency work the straightest and
shortest paths are best.  These are often not at nice axis aligned angles.

>> Given a similar problem, This is what I might have created:
>>
>> (red=top, blue=bottom) I'm sure I don't have the same libraries as
>> you, but I think you'll get the general idea. Notice the power and
>> ground traces are heavier, and shorter where practical.

For a two layer thru hole board, I would have set up the bottom layer as the
primary interconnect, and the top layer as a pseudo ground plane.  It
wouldn't be a real ground plane since some traces will likely need to be
routed there, but the intent would be to make those traces short and
isolated.  Small islands in a ground plane don't matter much.  Just be
careful that a bunch of small traces don't clump together to make a big hole
in the ground plane.

I have a standard setup for such boards.  I define the pseudo ground plane
in Eagle as a polygon, and set the cost for routing in that layer very high.
Initially the cost will be low to guarantee a solution, but this is cranked
up early in the optimize passes.  After 8 optimize passes you usually get a
nice board.  Your board isn't very complex, and I expect this technique
would work very well on it.

>> I also notice there's a few things I would probably add. Mounting
>> holes?

Or areas in the corners for rubber feet.  For lots of prototype boards I
never intend to put them into a case, just stick rubber feet in each of the
corners.

Another few niceties I like to add:

1 - Put the customer-visible name of the product on the silkscreen, company
name, and the date.  For example, the current production version of the
ProProg has:

  Embed Inc
  ProProg
  Version 2
  2 Aug 2004

in the lower left corner.  If you're making boards for yourself, similar
information is still useful.  Three years and 2 revs later it won't be as
obvious as you think to remember which board is which.

2 - Internal name or part number on the top copper along the edge somewhere.
This is the same name I use for the project name in Eagle and that all the
files for this project start with.  For example the ProProg has "PPRG2" in
copper near the lower middle.

3 - Take the trouble to clean up the silkscreen after placement and routing.
Part designators at all angles, under parts, and over vias is a pain to use
later and makes it look amateurish.  Yes, this takes a little work, but
doing it right usually does.


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