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[DPRG] ExpressPCB update

Subject: [DPRG] ExpressPCB update
From: Sluggy slugmusk at linuxlegend.com
Date: Thu Dec 12 01:17:01 CST 2002

rten at new.metronet.com wrote:
 
> Awaiting a report with baited breath, like the cat who ate cheese and
> crouched beside the mouse hole.

Hehehe

All in all, it's pretty usable. It was not as intuitive as I'd hoped it
would be to add custom parts, but it took only a quick scan of the help
screen to make it work. More on that in a minute.

As for linking a schematic to a circuit board, it is a manual process,
but it is essentially a computer assisted version of the manual process
I've used before.

With my previous boards, if there were not many parts, or if I was
working on only a small bit of it, as is the case on the ever-evolving
FlashLite/FleaBot I/O board, I would simply make the traces without the
benefit of a schematic; find that pin 1 of one chip hooks to pin 6 of
another chip and make that trace. Then the next trace, etc.

If the design had a few chips, I'd manually draw a schematic with either
a pen and paper or Autosketch, run a copy of it (don't mark up your
original, just in case), then run the traces, marking each schematic
connection with a highlighter as I completed that trace (or that part of
the trace)

ExpressSCH lets you draw a schematic with an extendable library of
components. The components have their pins defined. As you place each
part, you double-click on it to assign a part number (U1, T13, R7,
whatever; there is an autonumbering aid, too). Then when you run
ExpressPCB, you place the right type of components (DIP14, 1/4W
resistor, connector, etc) then double-click and name them to match.
Finally, you link the schematic to the board.

Once they are linked, in ExpressPCB, you select the netlist highlight
tool and click on any pin of any part. If that pin is connected to
anything else, all the pins that need to be connected together will be
highlighted in blue. Then you can manually lay the traces out to make
all the connections. It can help to have a printout of the schematic to
refer to.

Adding custom components in either stage is similar.

For a schematic, use the line tools to draw the outline of the device.
Then place the pins. At this point, the pins are really just dots.
Arrange them however it pleases you. Once you are happy with the layout
of the part, double-click on each pin to assign a pin number and
description to it. This will automatically give you pin number and
description lables, which you can drag to place on the drawing. Once all
those are done, highlight everything for that part and group for
component. This will let you label it with the part number and a generic
name "U" or "T", etc. The new component will show up in a list of Custom
Components and creates a single file for that part. I suspect that you
can send your custom parts to ExpressPCB for inclusion in later
versions, though I have not actually seen anything like that.

Adding a PCB component is usually very similar. Lay out solder pads or
holes as needed, double click on each one to provide it's description,
pin 1, 2 whatever. Then you group them together for a component, naming
them "DIP16" or "oscillator" or whatever. Then it's ready to place and
link.

It's oretty and I'm pretty sleepy or I would probably go on :)

Sluggy!

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