Re: gEDA-user: gschem, nets, and netlists

[Stephen Meier <smeier@AlchemyResearch.com>]

PCB dosn't seem to care if you have extra landpatterns.


Stephen Meier wrote:

> PCB also dosn't like nets sharing pads. I think the answer is this. 
> Use the virtual symbol trick but instead of overlapping their pads put 
> them close to each other. Do all of your routing work. Then remove the 
> virtual symbol from the schematic and connect the nets. Regenerate the 
> net list and load it into pcb. Now you should have your fat traces and 
> your skinny traces but you will need to connect the skinny traces to 
> the fat traces by connecting the two pads of the virtual element 
> together.
>
> Steve Meier
>
>
>
> Bert Douglas wrote:
>
> > Thanks much for the answer Stephen.
> >
> > I was thinking about post processing the netlist with a python script 
> > to remove the virtual component before it gets to PCB.  Do you think 
> > this will work?  This would avoid having to place the virtual 
> > component, and would avoid DRC warnings.
> >
> > Can PCB accept "overlapping" nets?  Something like this:
> >
> > net1 skinny pin1 pin2 pin3
> > net2 fat    pin3 pin4
> > net3 skinny pin4 pin5 pin6
> >
> > Thanks much,
> > Bert Douglas
> >
> > Stephen Meier wrote:
> >
> > > I think you are right in creating a virtual object with two pins to 
> > > break your net. PCB will expect a real component for this virtual 
> > > object. You will need to create a pattern with two overlaping pads. 
> > > However you can expect PCB to complain about the two nets being 
> > > shorted together.
> > >
> > > Steve Meier
> > >
> > >
> > > Bert Douglas wrote:
> > >
> > > > Hi guys,
> > > >
> > > > I have a long net.  But some parts of it need to use fat traces. I 
> > > > need to communicate this information to the autorouter somehow.
> > > >
> > > > So I would like to have one gschem net be written to the netlist 
> > > > file as multiple nets with assigned names.  Is there a way to do this?
> > > >
> > > > Or alternatively, is there a way to use a virtual, zero-size, two 
> > > > pin component to achieve the same result.
> > > >
> > > > Thanks much,
> > > > Bert