I have a layout without schematic or netlist and need to modify pads on previously created footprints so that they land on GROUND and POWER (internal) layers. Is it possible to manually edit pads so that i can achieve this?
Should not be a problem as long as Pcbnew can read it.
- No back annotations!
- Limited drc funktionality!
Has the pcb ever been connected to a schematic or netlist. If yes then you already have nets in it and can simply assign the net for GND to the pads in question. (manually edit the pad properties.)
If there never was a netlist then you will need to work without DRC as it is net based. Meaning set the interactive router to highlight collision and “allow DRC violations” (interactive router settings can be reached from the right click context menu while in routing mode and from some menu but i do not remember which one)
And then there are tools like wireit WireIt: PCBNEW plugin for adding/cutting/swapping wires in the physical layout which can be used in both instances.
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What sort of project is this?
Gerbview can for example open some gerber files and then backport a lot of usefull stuf into Pcbnew but it does not (yet?) extract any netlist info.
Another way for not having a netlist is that some users think it’s not worth drawing a schematic for “very simple” designs, such as a 18650 battery board with fuses. and a connector. In truth though, having a good netlist offloads the brains and enables KiCad to do a lot of DRC checking to prevent all kind of “silly” mistakes.
Schematics for such “very simple PCB’s” are also very easy to make (about 15 minutes) (after the initial learning curve).
Having a schematic and netlist also helps in other ways.
In the example of the battery board for example, the first iteration just had a regular thin section of PCB track as a “fuse”, while later versions had a real Footprint for the fuse, which helps in uniformity, because the length of the thin section also determines the amount of cooling and therefore the current at which the fuse blows. (Copper melts at 1358K so any cooling may have a significant impact. With a real footprint, it’s also much easier to change all the “fuses” in a later revision of the project, and this relates to your:
From the little information you’ve given, I think you are asking the wrong questions.
It should not be: How do I edit a PCB without a netlist", but: "How do I create a netlist for my PCB to make editing easier and more robust.
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If those NET names already exist, it is simple - you just edit any pin’s NET Name.
If those NET names do not already exist, they must be added, and you can use the nifty WireIT plugin, (linked above) to add connections (and also merge and split nets)
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