create Ground plane at gnd ?
Hi,
I'm used to design PCB with some other software (Kicad, proteus ARES,...).
I've made today a small PCB for a Jeenode board.
I wonder why ground plane is not link to gnd signals ? where can i define to which potential is the ground plane?
by default, ground plane is not linked to anything (so this not really a ground plane ... ? )
Thanks,
Rzbo
Hi Rzbo,
Ground plane will link to any connectors named "gnd" or "ground", case-insensitive. Currently, that is the only control available.
HTH,
- j
Hi,
It seems that it doesn't work (I have version 0.6.4). I will post a screenshot of my project this afternoon.
see you,
Rzbo
Here is a screenshot :
http://minbiocabanon.free.fr/public/20111218_fritzing/fritzing_ground_plane.png
I have check again nets... ground plane is connected to GND ONLY if I already draw manually a wire.
example : J3 pin3
But if I do not tied manually a GND wire, ground fill neither do it... example : J4 pin3 (green rat's net)
Maybe thermal pad function is missing ?
Other example : on the right connecteur 2x5 (J7), the right row is all connected to GND... ground fill should tied them to GND ground plane with thermal.
Best regards,
RzBo
Hello, my design uses vias to ground plane (signal on the top layer, ground on the bottom layer). I tried to follow the advice above and named the vias gnd or ground. Then I pour copper on the bottom side. But the copper nicely avoids the via, which is then left unconnected. I tried to connect two vias named gnd or ground with a wire (on the bottom side) also named gnd or ground, but still the copper does not contact to it.
So, what is the correct procedure to connect a via to the ground plane? I know one can manually add wires between the bottom via and the ground plane, but this is tedious, as it needs to be done after pouring the copper. Each time I want to change something to the design, I need to remove all those wires, remove the copper, then pour copper again and add the sames wire again.
Regards, Bernie
Hi Bernie.
Naming the via "gnd" or "ground" does not work because you are actually naming the part, not the connector. That's not a bad idea going forward, but it won't work for you now.
What you could do in the meantime is make a custom part, which is essentially your own custom via. Then you really could name the connector "gnd" and the ground fill would make the connection.
The only problem with a custom via is that you won't be able to resize it, but I'm hoping you're basically sticking to one size.
HTH,
- j
Hello Jonathan,
I created a via component the following way. (There is a white square on the top-right to ease selection. It is possible to move this component, a little hard however but possible.)
<?xml version='1.0' encoding='UTF-8'?>
I created a component by editing a screw terminal which I already had in Mine for component edition tests. In the connection editor I made sure to have one connector and changed its name and description to gnd. I tried to set it to male and also to female. Then I poured copper on top, and on bottom layer, but still the copper avoids the component.
Where did I do a mistake ?
Bernie
(From what I understood, I drew a copper ring that has an empty center of a given diameter, and this is going to be used as the hole diameter.)
Here is the SVG code again with [ ] instead of < and >. I hope it is readable now.
[?xml version='1.0' encoding='UTF-8'?] [svg baseProfile='tiny' version='1.2' height='1.2mm' width='1.6mm' viewBox='0 0 1600 1200' ] [g id='silkscreen'] [line id='horizontal-top' stroke='white' stroke-width='20' x1='1200' x2='1580' y1='20' y2='20'/] [line id='horizontal-bottom' stroke='white' stroke-width='20' x1='1200' x2='1580' y1='420' y2='420'/] [line id='vertical-right' stroke='white' stroke-width='20' x1='1580' x2='1580' y1='20' y2='420'/] [line id='vertical-left' stroke='white' stroke-width='20' x1='1200' x2='1200' y1='20' y2='420'/] [/g] [g id='copper1'] [g id='copper0'] [circle cx='600' cy='600' fill='none' id='connector0pin' r='450' stroke='rgb(255, 191, 0)' stroke-width='300'/] [/g] [/g] [/svg]
Hi Bernie,
Best way for me to have a look would be for you to save the part and email it to info .at. fritzing .dot. org. You can either select the part and choose "Export" from the part menu, or you can save the sketch the part is in--use "Save as shareable" under the File menu. The SVG looks ok, but I also want to have a look at the fzp file.
Cheers,
- j
A via does have a connector and its connector can be set to a ground fill seed: RMB in the center of the via (while the popup label says "1 via" which means the first connector of the via) and choose "Set Ground Fill Seed." So I don't understand why you say it does not have a connector.
Also, I don't understand what characteristic of a custom via part would be necessary to make it work as a ground fill seed. (a hole, with no copper ring in either layer, a circle with line width 0?)
I experimented with a fresh design having a single via, whose connector is set as a ground fill seed. Ground filling avoids the via.
I think this is a common use case. For simple SMD designs, where all non-ground traces can be routed in a single plane (the top) it is very common to make the bottom completely copper, a ground plane. It has EMI advantages, and since the ground net is often one of the larger nets, connecting other part connectors to ground via a nearby via to the ground plane often makes autorouting work better.
For through-hole (part mounting) designs, ground fill does need to avoid every non-ground hole (whether or not every hole is through plated or has a copper ring on the bottom), since a complete ground plane on the bottom could easily mechanically short to the wire leads of through hole components.
For now a workaround for this use case is a certain constrained order of board layout:
- place all through hole components and other holes
- generate complete copper or ground fill (both top and bottom)
- delete the copper on the top
- place SMD components on the top
- create nearby vias and wire them to grounded connectors (the vias will have continuity to the ground plane on the bottom)
- autoroute the top and make manual adjustments to the routing
Hi Bootchk.
It's actually a size issue. You'll notice if you make your via larger, the ground fill will adhere to it.
- j
I run into the via size issue constantly and it shits me. There is no reason ground fill should be ignoring the smaller via's at all.
A trick I often use to get around the issue is to connect two via's that are suppose to be grounded with a trace, as the ground fill WILL connect to that.
I'd really like to see the fritzing guys improve the ground fill in an upcoming version, because it does fail pretty annoyingly at times.
Dear Lemming,
Since 2010, the "fritzing guys" include exactly one programmer (me)--who is only supposed to be working half-time. Furthermore, at last count there are 460 open issues on the issue tracker assigned to me. In other words, there is a very good reason why ground fill is ignoring the smaller vias--because under current conditions it is not possible to fix every bug and implement every feature request.
Now since Fritzing is an open-source project, people are welcome to write the code themselves.
Or, if every time anyone gets annoyed by something in Fritzing they buy a starter kit, or use the Fab service, or send a donation, then maybe we could hire another programmer and get to a few more of these issues.
- j
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