Getting random ERC errors

[Aaron_Williams]

I am creating a board with 96 WS2813-mini LEDs broken down into 9 rows. Since there is so much duplication I have used copy block/past and duplicate block. I am now seeing random ERC errors about unconnected pins even though they are connected. If I move the traces elsewhere it often fixes it, but then another random error pops up.

My project is at https://github.com/aaronw2/ears-ws2813-mini

Additionally, even though all footprints have been assigned, nothing shows up in the PCB editor.

This is with 5.1.2, wxWidgets 3.0.3 running on OpenSuSE 15.0.
Application: kicad
Version: 5.1.2-5.1.2, release build
Libraries:
wxWidgets 3.0.3
libcurl/7.60.0 OpenSSL/1.1.0i zlib/1.2.11 libidn2/2.0.4 libpsl/0.20.1 (+libidn2/2.0.4) libssh/0.7.5/openssl/zlib nghttp2/1.31.1
Platform: Linux 4.12.14-lp150.12.58-default x86_64, 64 bit, Little endian, wxGTK
Build Info:
wxWidgets: 3.0.3 (wchar_t,STL containers,compatible with 2.8) GTK+ 2.24
Boost: 1.66.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.59.0
Compiler: GCC 7.3.1 with C++ ABI 1011

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

---

note by admin corrected use of ERC vs DRC: ERC is the electrical rule check of eeschema, DRC is the design rule check of pcbnew

[pedro]

@Aaron_Williams

I am now seeing random DRC errors about unconnected pins even though they are connected.

If you are talking about GND and VCC pins, they are not connected. When a pin is connected to a wire, the little circle at the end of the pin vanishes.

[pedro]

Non-connected

Connected

[Aaron_Williams]

In my case, EESCHEMA is showing that it IS connected, the junction is present.

[pedro]

Could you then tell us which is the error message you get?

[Aaron_Williams]

This has been marked and confirmed as a bug. https://bugs.launchpad.net/kicad/+bug/1827773

[pedro]

The answer was in the FAQ

ErrType(3): Pin connected to some others pins but no pin to drive it

Additional reading about pin types in general: https://forum.kicad.info/t/electrical-type-of-schematic-symbol-pins/9439 A good explanation about power symbols can be found in this stackexchange answer by @Seth_h KiCad does check if every component is connected to supply lines (*1) as a missing supply is a common mistake to make. Getting the error “ErrType(3): Pin connected to some others pins but no pin to drive it” means that KiCad thinks that some supply pin is not properly connected. Eithe…

[paulvdh]

I do not see the bug.
As Pedro (and Launchpad) already mentioned it is just the missing power flags.
The amount of LED’s, the story around it, and that KiCad picks just a random pin to show the error all make it more confusing.

When I tried to drag a symbol with “g”, the wire bend at the expected location, which clearly shows they are connected. (Press Esc to cancel the drag).

When I added the PWR_FLAG to both +5V and GND the ERC errors dissapeared.
With the PWR_FLAG’s it looks like:

Also:
If you often have schematics with many repeating symbols, you may want to look into Skidl. It is a Python library to help with generating netlists from code. It is a sort of VHDL for schematics.
There are also various scripts for generating repetitive stuff on a PCB. Either in Pcbnew (Replicate Plugin) or completely from scripts without Pcbnew ( Go get Skidl klock example).