I recently completed my first PCB which was done entirely with the
gEDA suite. Previously I have used gschem and then output a netlist
file and contracted the layout work to be done in PCAD. As I went
through the learning process with the PCB layout package I noted down
the questions which came up and any thoughts/comments which I had. I
hope that sharing those thoughts will contribute to the community and
these two excellent packages. These comments are mostly about my
experience learning and using PCB. I managed to answer most of my
questions/issues by reading the manual/wiki/mailing list.
I have been really impressed with both tools. Thank you to all of you
who put so much effort into making the gEDA suite, and continually
improving it. I am deeply grateful for all your effort, and I hope
that I can contribute to this community.
I am working in Windows, and running both gschem and PCB on top of
cygwin. I come from a background of working with PCAD, so that forms
my frame of reference for PCB layout (although I never laid out an
entire board in PCAD - mostly just engineering input).
I downloaded the latest stable sources and compiled them. I followed
the info on the wiki and it all worked perfectly (
http://www.geda.seul.org/wiki/geda:cygwin ). One of the things that I
did notice is that the pre-compiled PCB binary for Windows was
*really* slow, and I am very glad that I recompiled on cygwin - it
resulted in a much faster and more pleasant experience. There was also
some other randomness in the Windows version, like strange menu
behaviour (FYI I am running Vista).
When I started I found the user interface very confusing. There were
two things which caused this. Firstly, there are certain "expected"
responses coming from a Windows background, like expecting a context
menu on a right click. After working with PCB for a while I now keep
right clicking to pan the screen around in other programmes :) Once I
had a feel for the actions, it became quite easy to work with, but it
is an initial bump that people have to get over. I had quite a bit of
motivation (had to do this board in PCB regardless), while people who
are considering options might not put in the effort to get over that
bump. I think the controls should remain, what is important is to make
sure that people can easily get over that initial awkwardness with the
controls. The sooner they get past that the sooner they can start
having fun.
The second thing about the interface was that it was inconsistent with
gschem. Left/right/middle clicks do different things, which is
unexpected. I think that is quite a crucial issue to look at and
consider. Although the two programmes are separate, they are still
part of a suite. Consistency in user experience can result in a much
smoother and more pleasant process.
I also had some trouble figuring out the select tool (later I realised
I didn't really ever need it though, but at first it caused me some
confusion). What it selected seemed a bit random. Sometimes I would
end up selecting a pad, sometimes the object on the other side of the
board - it was just confusing, and I couldn't figure out how it
decided what to select. There is also different behaviour for moving
objects based on the selection. If the object is just dragged, then
the lines are extended/dragged with it, if it is selected and then
dragged the lines don't. It is a useful feature, but if you don't know
about it, it is confusing.
I've seen it come up a couple of times on this mailing list that
people think there are only 8 layers supported in PCB. It is clear
from all the comments here and on the wiki that the default is up to
16 layers. I think one of the problems is that on page 4 of the PCB
manual under "Overview" it says, "Up to 8 copper layer designs."
Fixing that may result in fewer questions about the layers.
On the issue of layers, I kind of lucked out while looking through the
menus to figure out where the layers and board size menus were. The
File->Preferences menu seems like an odd place to find board (project)
related info. It would be nice if it was more immediately obvious how
to change the items hidden away there. It is easy to google for an
answer and find it quickly, but again that adds to the "hump" that new
users have to get over. The faster users get over the hump, the
greater the adoption of this excellent tool (and the greater benefit
to the community around it).
This might be a result of coming from PCAD, but I found it quite
strange that the mask and clearance's are set individually for pads.
It makes absolute sense to have that option, but I expected it as an
override for global values, rather than having each pad/pin/etc set
individually. Setting a global value and then overriding it on a
pad/line/etc. seems like an easier way to control these two values.
Similarly being able to control the clearance for a polygon, rather
than for a pad/line seems to make more sense, but again I am carrying
this over from my PCAD
