> El dom, 23-10-2005 a las 07:51 -0400, John Luciani escribió: > > > Heavy/light symbols > > > > If you want to display correct pin numbers you need to specify a > > package type for some symbols. For example: the LM326-2.5 reference > > has two packages --- DIP8 and TO-92 with the following pin > > numbers: > > > > Pin Numbers > > > > TO-92 DIP8 > > Anode 1 4 > > Cathode 2 8 > > Adj 3 5 > > I meant having two kind of files: > - One storing the graphical symbol. > - One which inherits the graphical symbol from the latter. This one > includes the necessary attributes: footprint, device, and so on. > > In the example you wrote, there would be a LM326-1.sym symbol with only > the graphical representation, and maybe some common attributes. > Then, there would be one LM326_TO92-1.sym symbol and one > LM326_DIP8-1.sym symbol. Each one have its own attributes, so there's no > footprint conflict, and both include the LM326-1.sym as a schematic > include it now: without copying its contents. This way, if you change > the LM326-1.sym symbol, the graphical symbol of the other two will > change, but not their attributes (they are specified within each one, > and not in the LM326-1.sym file). > Sometimes the same chips housed in different packages have different count of pins (78L05 in SO8 has four GND pins for example) and the new symbol system should support this. For example pin number 0 may mean no pin here.
> > Sometimes it useful to have different sizes of the same symbol. If I > > have a schematic containing an LED driver connected to 16 LEDs I would > > use a small LED symbol to improve schematic readability. If a > > component needs many decoupling capacitors at specific pins (Chipcon > > radios) it is useful to use a small capacitor symbol. > > > > Scalable symbols would be nice. Currently I use names like LED.sym, > > LED-small.sym, CAP.sym, CAP-small.sym which works fine. > > [snip] > > ATM I don't know how it would be implemented. This feature will only > scale the graphical symbol, and not the text, if we want to preserve the > readability. Regarding the graphical symbol, it can only be scaled by a > given factor, maybe 50%, in order to keep the pin to pin spacing within > the grid. Am I right? In my opinion scaled symbols will not look good and it is also possible to scale the schematic drawing when printing. I have created some symbols with reduced size, comparable to those found in other schematic editors (Orcad, Protel, etc). They are not 100% compatible with existing (big) ones. I can publish my symbols under gEDA license if there is an interest. Wojciech Kazubski
