kicad-developers team mailing list archive

[Joseph Chen <joseph.chen59@xxxxxxxxx>]

@Wayne and @JP,

Could try ERC on this simple schematic file?

Attached, you can find a test schematic file that has an unintended 
unmatched local labels, and current kicad ERC does not detect them.

In the test schematic file, there is a mis-spelled local label on the 
right hand side.  The local labels are constructed with an intention of 
using them to serve as ratnets, not just a convenient text.
With this kind of mis-detected errors, the PCB will not have the 
intended ratnet at all and thus no copper track will be laid out, and 
thus the manufactured boards will be bad.

--Joe

On 09/13/2015 01:00 PM, Wayne Stambaugh wrote:
> On 9/13/2015 2:45 PM, jp charras wrote:
> > Le 13/09/2015 20:11, Wayne Stambaugh a écrit :
> > > On 9/13/2015 1:50 AM, Lorenzo Marcantonio wrote:
> > > > On Sat, Sep 12, 2015 at 10:49:59PM -0600, Joseph Chen wrote:
> > > >
> > > > > Though you don't approve the change now, I hope you would approve it
> > > > > sometime later soon, like maybe RC2. I am saying this because I
> > > > > believe the fix is crucial for KiCAD to be improved towards a
> > > > > production quality EDA, after I encountered my PCB's near "DEATH"
> > > > > situation.
> > > > I don't think that checking unmatched names is so critical. In fact
> > > > *most* of my labels are simply used to... label nets, not to create a
> > > > connection. That way during routing I can see the signal which need
> > > > particular attention (also it's easier to set netclasses in this way)
> > > >
> > > > A distraction like a mistyped label is akin to connecting a wire to the
> > > > wrong pin (one time I flipped over an amp symbol... lot's of smoke
> > > > happened :D); no ERC can save you from that.
> > > >
> > > > The *only* feature useful in the schematic DRC is the 'unconnected pin'
> > > > warning; all the other ones (signal conflicts, power pins and so on) are
> > > > a complete nuisance (at least for mixed signal and analog-heavy boards).
> > > > Even for digital boards a filter inductor on a power pin would give a
> > > > missing power warning :P
> > > When a pin is connected to a wire with a label that doesn't go anywhere,
> > > does the ERC generate an error?  It probably should because technically
> > > this is still an unconnected pin.  This is a more sensible then checking
> > > for unmatched label names for the reasons Lorenzo stated above.
> > Yes, because unconnected pins without no connect symbol are detected.
> Then this should be adequate to detect the problem as it was described
> or we have a bug in the ERC code.  @Joseph, did you get an ERC error
> with your mismatched labels.  If so, then the ERC did it's job properly.
>   I don't think your changes make any improvement and in some cases will
> cause issues with net labels.

Attachment: kicad-unmatched-local-labels-schematic.tar
Description: Unix tar archive