On 09/11/2010 10:37 PM, Peter Gammie wrote:

> Fair enough. I'm not too bothered about the command line stuff, but
> perhaps you expect a shiny GUI? 

Of course I expect a GUI.  And forward and back anotation.  And common
commands between the schematic and layout editor.  You know, standard
stuff for computers for the last 10 years or so.

Now Eagle (and maybe KiCAD - memory's fuzzy now) does have a command
line.  You could get away with not using the mouse if you really wanted
to.  I do use a few command line commands for things like turning layers
on and off and stuff like that.  It's faster than navigating the GUI.

> I'd almost be happier drawing
> schematics by writing a program...

You can definitely do that in KiCAD if you like.  The drawing and layout
files are ASCII text files.  Syntax similar to SPICE.

> 
> Also how do these programs go for maintenance? I imagine (in my
> naivete) that you design a board, get it fabbed and then find out it
> has a layout or circuit issue. How hard is it to adjust the schematic
> and redo the board?

In Eagle it's simple.  If you need to move a component on the board or
change package type, you just do it.  If you need to delete or add a
component, you do that in the schematic editor.  In the case of deleting
parts, the forward annotation rips up the part and as much of the
connecting trace as is safe.  When adding a part, the footprint is
deposited at the lower left of the page outside the board outline with
rubber bands connecting it to the circuit.  You simply drag it to
wherever you want it.

In Eagle, a Part is a combination of the schematic symbol and one or
more board footprints.  A part can be specific, say a 2N2222.  It would
have an NPN symbol for the schematic and one or more footprints for the
different packages that type of transistor comes in.  A part can be
generic.  An NPN transistor associated with all the common footprints.

One can add a value to a generic part after it's laid down.  I could
make an NPN be a 2N3904 by simply changing the "value" field.  Generally
for parts that get used a lot, one does a specific part.  Generic parts
are saved for infrequently used items and items such as capacitors and
resistors where hundreds of values share the same symbol and footprint.

Eagle and KiCAD automatically connect nets (names given to wires on the
schematic) so one doesn't have to draw long wires or buses unless he
wants to.  Makes the schematics much cleaner looking and saves a lot of
labor.

John


-- 
John DeArmond
Tellico Plains, Occupied TN
http://www.neon-john.com    <-- email from here
http://www.johndearmond.com <-- Best damned Blog on the net
PGP key: wwwkeys.pgp.net: BCB68D77

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To post to this group, send an email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/neonixie-l?hl=en-GB.

Reply via email to