Re: gEDA-user: PCB: Stale rat's nest?

[Vanessa Dannenberg <vanessadannenberg@xxxxxxxxx>]

On Thursday 02 March 2006 18:49, Ales Hvezda wrote:

> > * Seeing that the log always contains a few error messages ...
> 	You can control this via an rc keyword in a *gschemrc file.

Ok, noted.

> 	gschem does not support this sort of "transparent zooming/panning".
> 	I really ought to disable the ability to even do this.

Please don't!  It's extremely handy.

> > * Changing the Zoom level should *never* cause zoom in/out events to be
> > added to the undo history...
> 	This is a religious issue.  Different people have very different
> 	opinions on this.

Perhaps, but consider this:  If I zoom in or out, have I changed the content 
of the schematic?  A quick test shows that the current zoom setting doesn't 
get saved into a gSchem file anyway, so why even add these zoom events into 
the undo history?

> > * As you know, most standard 74xx logic contain multiple gates per
> > package...
> >
> > * gSchem should never require the user to manually give each part a
> > unique name, e.g. U1, C5, R22... 
>
> 	In gEDA/gaf, the user is responsible for assigning refdes packages
> 	and slotting.

Nevertheless, the program should *still* number the parts as they're added.   
After all, the person drawing the schematic will surely know "ok, this gate 
will need to be in this package over here to keep it close to part Xyz, and 
draw the parts in order so that this happens automatically.

> 	Historically gEDA/gaf and PCB were developed at different times and
> 	by different people.  Maybe in the future things will come together,
> 	but for now they are different.

Fair enough.  Is it possible for the user to alter the program's settings to 
do this?  Or rather, could this be made into an option?

> 	gEDA/gaf does not only target PCB.  PCB is just one of many possible
> 	backends, so it will not limit available symbols to only PCB.

True, but as it says on the website and in a few places, PCB has become the 
defacto standard layout editor to be used with gEDA.

>
> > * Keeping with the 7400 example.. Place four NAND gates from a 7400 on
> > the schematic.  How do I order the gates so that each one is assigned to
> > 1/4 of a 7400 package, with the proper pin numbering?
>
> 	This is the designer's responsibility IMO.  Truely automated
> 	mechanisms cannot read the designer's mind.  Sooner or later you
> 	(or your circuit) will be burned by them.

True, however in many cases it's not an issue.  The reason I say that is that 
you still have to place a part on the board before you can add nets to it, 
and when placed, you'll already know what gates are already there.

The slotting and numbering takes place as you add the part to the schematic, 
and in Eagle for example, it's evident which gates belong to which packages 
( 7400 - IC2a, 7400 - IC2b, etc).  It's really just a matter of looking for 
the first part that has a free slot when you add a new gate to a circuit, and 
assign that gate to the free slot.

Why not make this an optional feature?  If the user doesn't like the on-demand 
numbering, they could just turn the feature off entirely.

> 	How did you create the board layout?  What are the exact commands
> 	you use here?   Ah, the lovely geda manager, yes, that is broken.

As I am not keyboard-oriented (I prefer a click-and-drool interface), I 
couldn't tell you the commands specifically.  What I can tell you is that I 
created the schematic using the exact proceedure outlined in the bug listing.

I did switch frequently between the gSchem window and a few other, unrelated 
programs.  Perhaps the loss of focus caused a bug to appear.  The broken 
schematic file is attached to this message (broken-four-gates.sch).  Note 
that this is just a test circuit with no actual purpose (I'm not even sure 
what it would do if you actually built it :-) )

> 	Pleaes don't use the geda manager.  It is my fault that this
> neglected program has been distributed at all.  Sorry.

Ok, I will refrain from using it.

> 	Did you read the above tutorial before attempting to from schematic
> 	to PCB?

No, I didn't.  In fact, I never knew about the tutorial (I probably overlooked 
it).  Anyway, I have it open in another window as I write this.  I'll go over 
it and see if I missed something.

> > I really hope to see either gEDA or KiCAD (the other one I'm tracking)
> > surpass Eagle some day soon, so I can retire that damn crippleware of
> > a program (Eagle) that I've used for way too long.
>
> 	gEDA/gaf is not a replacement for Eagle.  It does things very
> 	differently intentionally.

Well, not so much a replacement for Eagle as much as a stand-in, i.e. 
something that I can use to do the job with as little fuss as possible.

> 	You could always pay for the next step up for Eagle. 

And *that* costs more money than my fiance (our only source of income) makes 
in a month.  Eagle is good, but it isn't *that* good.

> It seems like it meets most of your needs now. :-)

It did up to the point where I decided to try something "big".  Eagle has a 
size limit of 4x3 inches (some 160x100 mm?) in the freebie version, and 
you're not allowed to sell things to make with it.  In order to go bigger 
than 4x3 inches in either direction, and to be able to sell what I make, I'd 
have to cough up nearly $1200.  Since my stuff is all FOSH(ardware) anyway, 
it seems silly to pay that kind of money for it.  

-- 
"Sometimes paranoia can be helpful. Usually it
isn't, and when you learn that, life improves."
Vanessa Dannenberg

v 20060123 1
C 29300 61500 1 0 0 7400-1.sym
{
T 29600 62400 5 10 1 1 0 0 1
refdes=U1
}
C 29300 60300 1 0 0 7400-1.sym
{
T 29600 61200 5 10 1 1 0 0 1
refdes=U2
}
C 31300 60900 1 0 0 7400-1.sym
{
T 31600 61800 5 10 1 1 0 0 1
refdes=U3
}
C 31300 59600 1 0 0 7400-1.sym
{
T 31600 60500 5 10 1 1 0 0 1
refdes=U4
}
N 29300 62200 28900 62200 4
N 28900 62200 28900 62800 4
N 28900 62800 32600 62800 4
N 32600 62800 32600 61400 4
N 31300 61600 31100 61600 4
N 31100 61600 31100 62000 4
N 31100 62000 30600 62000 4
N 29300 61800 28900 61800 4
N 28900 61800 28900 61500 4
N 28900 61500 30600 61500 4
N 30600 61500 30600 60800 4
N 29300 61000 28900 61000 4
N 28900 61000 28900 59500 4
N 28900 59500 32700 59500 4
N 32700 59500 32700 60100 4
N 32700 60100 32600 60100 4
N 31300 59900 29100 59900 4
N 29100 59900 29100 60600 4
N 29100 60600 29300 60600 4
N 31300 60300 31300 61200 4