Routing won't finish trace on pads

technically_not · December 27, 2020, 5:17pm

When I’m trying to draw a trace between two pads (definitely connected in the schematic, as indicated by the ratsnest), I would expect to click on the “Route Tracks” button (or press “x”), then single click on the starting pad, draw the trace by moving the mouse and clicking on points where I definitely want the trace to go, and finally moving my mouse onto the pad I’m aiming for, then double clicking to finish the trace, at which point I would expect the trace to be complete, and run from pad to pad.

What’s actually happening is quite frustrating, and required more clicks than I feel is necessary for drawing each trace.

When I click during routing, instead of the trace as it exists on the screen being “locked in” as it were, it only locks in up to the previous corner in the trace

Though it feels related, I suppose that’s a secondary problem to the trace not finishing where it should.

That picture shows the state of play after I have double clicked on the pad that I’m aiming for. If I move my mouse, the dark green section follows my mouse and does not keep the trace passing through the pad that I double clicked on, nor does it finish the trace drawing as I would expect.

What am I missing? Is there a setting? Is this just how KiCAD works? It feels much more cumbersome to layout a board if ending the track requires three clicks and a keyboard press (esc) which is what it currently seems to need. But I’m sure I’m doing something wrong.

Version info:

Version: 5.1.9-73d0e3b20d~88~ubuntu20.04.1, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3
Platform: Linux 5.4.0-58-lowlatency x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
    Boost: 1.71.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.68.0
    Compiler: GCC 9.3.0 with C++ ABI 1013

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

technically_not · December 27, 2020, 5:18pm

Uploading in a separate post because I’m a new forum user…

That image shows the state of play after I’ve clicked the first pad (6), moved my cursor to where it is and clicked once. I’d expect the click to tell KiCAD that I want the trace to go through the point I’ve just clicked on, but instead it only locks in the trace up to the previous corner.

paulvdh · December 27, 2020, 5:49pm

So there are two issues here. First is that your tracks only get finalized up to the “N-1” segment. This is by design, but there are other people who do not like this behavior and have opened an issue on gitlab for it. A better solution is to simply ignore it. Once you get a big more experience with KiCad you will notice that the Interactive Router very easily shifts around track segments a bit and this is a good thing. Routing will be a lot quicker and more effective if you adopt to this, by stopping to worry about exact track locations and corner points and just lay the track from A to B without worrying too much about it’s exact location. And then later, maybe come back for a cleanup pass.

The second question:
To end a track, you do not have to double click on a track. A single click suffices. I guess that your “double click” was too slow and interpreted as two single clicks (with results: first click ends the track, 2nd click starts a new track).

If you combine this then routing the track in your example is as simple as:

Press X to get into routing tracks mode.
Single Click on pad 6 of the 8 pin connector.
Single click on J3, pin2.

fred4u · December 27, 2020, 6:28pm

@paulvdh recent 5.99 builds have the option to “fix all segments” (instead of fix “n-1”).
I’ve test-driven the new mode and it does not work for me. Have you tried it? I’d like to know your impression on the change. Fortunately there are recently added options for new router behaviors (this “fix all” and the gesture-based “autoposture” which I also don’t grab).

technically_not · December 27, 2020, 7:38pm

Hi everyone, thanks for your help.

@paulvdh, your suggested method still doesn’t work. I wasn’t being too slow with the double click, but using a single or a double click has exactly the same behavior - the track is not completed when I click on the pad. It’s nice to know it’s supposed to though!

I’ve just been using the stable builds in the Ubuntu repo, but I like the sound of being able to toggle that, though I can see the use of the “n-1” segment. In fact I think my personal ideal behaviour would be if it fixed n-1 segments, but also fixed the direction of the next segment. But obviously I will get used to however it works.

This shows me clicking three times, once to select the routing tool, once at the first pad and once at the second.

To clarify, this happens with any combination of pads, and on other projects too.

fred4u · December 27, 2020, 7:55pm

To me it seems some collission is preventing you from finishing the track.
Change the routing mode (Router > Router preferences) from Shove to Higlight collission mode and see if something shines bright yellow.

radix · December 28, 2020, 1:06am

Go to settings and enable snap to pads at least during track creation.

technically_not · December 28, 2020, 8:36am

@radix That’s it! Thank you so much, that’s all sorted

system · March 28, 2021, 8:36am

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