Light vs. heavy is nomenclature which I just made up. Perhaps there are other terms? If so, I don't know what they are. Anyway, this is what I mean:
Gschem currently uses "light" symbols. That is, each symbol in the symbol lib has almost no built-in attributes. It is up to the user to place the symbol and then add all the attributes he needs manually, either using gschem's attribute pop-up or perhaps using gattrib or an equivalent program. By "heavy" symbol I mean that each symbol in the lib has a bunch of attributes already attached to it. In this case, the user just sticks the symbol into his design, and he is then ready to netlist without further work. Particular attributes which users seem to want built into the symbol include "footprint", and spice models. Protel is an example of an EDA system with "heavy" footprints. The reason for the discussion is that we constantly hear reports from newbies that they want better integration between gschem and PCB. A common complaint involves the fact that newbies don't want to -- or don't know how to -- stick PCB footprint names onto the symbols while creating their schematics. I just got a few more in my in-box last week, which triggered my Free Dog suggestion. It is true that it is not a priori clear what footprint names to stick into symbols until you have had some experience with PCB. Nowhere in any documentation does it tell you what footprint names go with which parts. Indeed, if you use the M4 footprints you've got to look through the files themselves to find the footprint names. The newlib footprints are a little better since the footprint name is the file name. Nonetheless, newbies are often thrown for a loop when it comes to putting footprint attributes into the schematic. This is the reason I bring the subject up. Personally, I like gschem's attribute mechanism just the way it is. "Light" footprints provide maximum flexibility to users who know what they are doing. Moreover, bulk managing footprints is easy using gattrib. On the other hand, Ales had some good ideas about how to further simplify the selection of footprint attribs. I thought I would share with the teeming Free Dog multitudes a couple of my recent e-mails from newbies complaining about footprint attributing. Then perhaps we would talk more about various improvements one might make to gschem which would be lightweight, but might also make it easier for newbies to attribute their designs. Any thoughts? Stuart > > Stuart, > > Could you give us a brief discussion on light vs. heavy gschem symbols? > > Thanks, > > Steve Meier > > > Stuart Brorson wrote: > > >-------------- Free Dog Gathering Announcement ---------------- > > > >The Free EDA Users Group will meet this coming Thursday, June 2nd. > >Once again, let's meet at the Starbucks across the street from Quantum > >Books on Ames St, between Main St and Broadway. It's about 1 block > >away from the Kendall Sq "T" stop. (In Cambridge, MA, USA, of > >course.) > > > >The meeting will be an open and informal working session. Bring your > >laptop! Some items on the agenda are: > > > >* Scilab vs. Octave showdown! (by request) > >* More discussion about "light" vs. "heavy" gschem symbols. > >* Your favorite issue here! > > > >Free Dog is an association of like-minded hackers and engineers > >interested in free and open EDA tools. We hold monthly meetings at MIT > >(and other locations) featuring informal networking, speakers, and > >camaraderie. Our goals are to learn more about CAD, engineering and > >scientific software, share ideas about our current projects, and -- > >most importantly -- have fun with like-minded people. We welcome new > >members and participants of all ages. Students are particularly > >welcome! > > > > > >Date: Thursday, June 2nd, 2005. (*** Note the change of day! ***) > >Time: 7:00pm > >Location: Starbucks Coffee, 6 Cambridge Center, Cambridge, > >MA, USA. > > > >For more details, please contact me privately at sdb (AT) cloud9 (DOT) > >net. > > > > > > > >
