delorie.com/archives/browse.cgi   search  
Mail Archives: geda-user/2016/08/10/23:47:29

X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient: geda-user AT delorie DOT com
Subject: Re: [geda-user] Wilkinson splitter - how to implement and use?
To: geda-user AT delorie DOT com
References: <23abdc31 DOT 72365e7a DOT 572529a9 DOT 212e2 AT o2 DOT pl>
<a5562efe70ac4b83b066facd19a46167 AT gwp>
<20160801162742 DOT GA27552 AT recycle DOT lbl DOT gov>
<20160801184707 DOT 7b3dda2d3c0d13e103a5ec59 AT gmail DOT com>
<a7acaf21-df0d-d209-d053-fcc470762ea3 AT ecosensory DOT com>
<s6n60rkz3g8 DOT fsf AT blaulicht DOT dmz DOT brux>
<201608012000 DOT u71K0pN2001967 AT envy DOT delorie DOT com>
<CAHUm0tO1-ke5jcKsqYstiajENUis2f=nn5=jZkaNQ+HGDVg6zw AT mail DOT gmail DOT com>
<CAM2RGhSxV=-czyN-vNRRzy8r1OErBcYSdT+uZ=-R86bsWyRcdg AT mail DOT gmail DOT com>
<20160802233304 DOT GA2086 AT recycle DOT lbl DOT gov>
From: "Dan McMahill (dan AT mcmahill DOT net) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
Message-ID: <53de010f-090b-f68e-9117-e36417debf31@mcmahill.net>
Date: Wed, 10 Aug 2016 23:44:44 -0400
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101
Thunderbird/45.2.0
MIME-Version: 1.0
In-Reply-To: <20160802233304.GA2086@recycle.lbl.gov>
X-CMAE-Envelope: MS4wfDwB5PX+IJrW2SBKyUbYSrbYhHKNzRxAlJ6Y+iKsq1Nl+PMWmgWpzCo4/05ReA3CccOejsQhuzqA2cKatQVJVsCsK356tJhvOaSoKXj68zYhbwhsAlX9
Uc2vN7UKfA+v8ZTGZE4MkTPic02FtdocOse7yWh9oadqmzqh4CP9f8a2
Reply-To: geda-user AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: geda-user AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com

On 8/2/2016 7:33 PM, Larry Doolittle wrote:
> Evan -
>
> On Tue, Aug 02, 2016 at 04:47:05PM -0400, Evan Foss (evanfoss AT gmail DOT com) [via geda-user AT delorie DOT com] wrote:
>> On Mon, Aug 1, 2016 at 6:44 PM, Erich Heinzle (a1039181 AT gmail DOT com)
>> [via geda-user AT delorie DOT com] <geda-user AT delorie DOT com> wrote:
>>> If pcb were modified to honour the flag, I could easily add a "nodrc" flag
>>> as discussed to the non-pad line element outputs of the utility.
>> I think we need something more subtle than nodrc. Having DRC turned
>> off for a specific footprint or any other board area is just as bad as
>> having DRC return bogus warnings/errors.
>
> I agree in general.  For the copper structures wished for to handle
> star grounds and Wilkinson splitters, we actually want the layer
> to exist for DRC purposes, but not for netlist purposes.  So a
> "nonetlist" flag?
>
>> The reality is that these structures are not footprints but functional
>> elements. They have design rules, just very different ones with higher
>> orders of complexity. We can't really have pcb process the full
>> complexity of these rules across the whole domain from DC to daylight
>> (or shorter) because of limitations in processing. It would also
>> require a level of developer time which is far past what pcb-* has
>> right now.
>
> Without diving into a more general capability set, this particular tweak
> _sounds_ simple enough to me.  But my limited experience poking around in
> the internals of the existing pcb code base makes me predict it will be
> difficult to do without breaking somethings else.  Maybe I'll look at
> pcb-rnd and see if that looks any more promising.


This has been on my wish list for a long long time.  A related topic is 
one of wishing for true hierarchical design.  Take something like a 
combline filter.  You have a combination of lumped capacitors along with 
some critically sized and spaced copper lines.  You'd really like to be 
able to group that all together and then only allow it to be moved 
around as a unit.  I supposed a mid ground would be the ability to 
create a group of footprints and traces that stick together even if you 
can't create multiple instances of the same thing.

-Dan


- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019