Internally connected VCC

Hi.

I want to create a daughter board with DAC and ADC. Board has a 10x pinout on both sides left and right. Both right one and left one have VCC pins. Those pins are connected on motherboard so I do not need to connect those on my board. IC on right side uses right side VCC and IC on left uses VCC on left pinout.

How to Fix this issue without DRC complaining ?
My project on github.

Well create two distinct VCC nets. Or use net-ties.

VCC in one net. How adding net-tie would solve my problem ?

I think you have the wrong idea about what a net is. A net defines a set of pins that need to be connected. So to get stuff that is not connected on the pcb you currently make you need to make different nets. (The electrons do not care what you call the copper feature.)


Net ties allow you to have different nets that are connected at some specified place on your current pcb. (But you are right it might not help with your current problem)

1 Like

Ok. Thanks. I will use separate nets then.

I found this dated but still very useful video about net ties: https://www.youtube.com/watch?v=zgaRkWHQCOk . Following the comments, I see that now KiCAD 5 includes symbols (but not footprints?) for net ties. Is it possible to have a zero-length net tie? This could be very useful in RF design.

KiCad 6.0 will have net ties as first class items. I think that will include “zero length” so that one item (a segment, via) would be part of two nets at the same time.

1 Like

There are net tie footprints in the lib. (It is a limited set but still)

@Rene_Poschl: Thank you for the information! Which (sub)directory is that?

Just search " net " .

@hermit: Thank you. I am looking for footprints.

Sorry but same principle. :wink: Click the 4th symbol down? (IC chip) and search there. As a lowly hack I get most of my footprint associations from that window when I’m doing the schematic.

@hermit: Thanks again! It seems I am having a problem with the search paths because I don’t see all these options when searching for “net.” And on the top of the frame it tells me that 969 items have been loaded (only, vs. your 9595). I suspect I have messed up my paths. I see that the repo libraries do get updated.

What is your current version number of the software, what OS and have you recently upgraded? Might have to wait for the folks that know what they’re talking about to wake up and get back on line before we get much further.

@hermit: No, I have not upgraded my OS recently. Here is the info from KiCAD:
Application: KiCad
Version: 5.1.4-e60b266~84~ubuntu16.04.1, release build
Libraries:
wxWidgets 3.0.2
libcurl/7.47.0 OpenSSL/1.0.2g zlib/1.2.8 libidn/1.32 librtmp/2.3
Platform: Linux 4.15.0-65-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
wxWidgets: 3.0.2 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
Boost: 1.58.0
OpenCASCADE Community Edition: 6.8.0
Curl: 7.47.0
Compiler: GCC 5.4.0 with C++ ABI 1009

Build settings:
USE_WX_GRAPHICS_CONTEXT=OFF
USE_WX_OVERLAY=OFF
KICAD_SCRIPTING=ON
KICAD_SCRIPTING_MODULES=ON
KICAD_SCRIPTING_PYTHON3=OFF
KICAD_SCRIPTING_WXPYTHON=ON
KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
KICAD_SCRIPTING_ACTION_MENU=ON
BUILD_GITHUB_PLUGIN=ON
KICAD_USE_OCE=ON
KICAD_USE_OCC=OFF
KICAD_SPICE=ON

I don’t know what libraries come packed with that but I’d be surprised if it wasn’t the full compliment. I pull the main from the main site. I think the FAQ has some path hints. But, as shown in the picture above, net-tie is its own category. Here’s where I have them:
hermit@NetTie.pretty:pwd
/home/hermit/kicad_V5_libs/kicad-footprints/NetTie.pretty
hermit@NetTie.pretty:ls -l
total 48
-rw-r–r-- 1 hermit hermit 873 Aug 29 2018 NetTie-2_SMD_Pad0.5mm.kicad_mod
-rw-r–r-- 1 hermit hermit 869 Aug 29 2018 NetTie-2_SMD_Pad2.0mm.kicad_mod
-rw-r–r-- 1 hermit hermit 1022 Aug 29 2018 NetTie-2_THT_Pad0.3mm.kicad_mod
-rw-r–r-- 1 hermit hermit 1010 Aug 29 2018 NetTie-2_THT_Pad1.0mm.kicad_mod
-rw-r–r-- 1 hermit hermit 936 Aug 29 2018 NetTie-3_SMD_Pad0.5mm.kicad_mod
-rw-r–r-- 1 hermit hermit 924 Aug 29 2018 NetTie-3_SMD_Pad2.0mm.kicad_mod
-rw-r–r-- 1 hermit hermit 1101 Aug 29 2018 NetTie-3_THT_Pad0.3mm.kicad_mod
-rw-r–r-- 1 hermit hermit 1087 Aug 29 2018 NetTie-3_THT_Pad1.0mm.kicad_mod
-rw-r–r-- 1 hermit hermit 994 Aug 29 2018 NetTie-4_SMD_Pad0.5mm.kicad_mod
-rw-r–r-- 1 hermit hermit 982 Aug 29 2018 NetTie-4_SMD_Pad2.0mm.kicad_mod
-rw-r–r-- 1 hermit hermit 1194 Aug 29 2018 NetTie-4_THT_Pad0.3mm.kicad_mod
-rw-r–r-- 1 hermit hermit 1186 Aug 29 2018 NetTie-4_THT_Pad1.0mm.kicad_mod

@hermit: Wow, thank you! I poked around. Net ties are in ‘/usr/share/kicad/modules/NetTie.pretty’ on my system. Now, I am not sure if I have to declare every subdirectory of ‘/usr/share/kicad/modules/’ as a separate path with a name in order to have access to all subdirectories under it (incl. the ‘Net.tie.pretty’). I think I do.

Check out this FAQ entry on how the library system in KiCad 5 works (yes, you need to specify each .pretty folder that you want to use):

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.