Newbie PCB layout questions

Layout
1

I’m a newbie in PCB layout and I am using it to make PCBs of some circuits I’ve built on small protoype pcbs. I use these for my model railroad.

  1. Why do I get so many ‘UNCONNECTED’’ WARNINGS/ERRORS when to me the traces look connected to me??
  2. Has anybody been able to download component footprint and symbol libraries to add to the KiCad available ones?
  3. What can I do to get my traces without wiggles? Does my mouse need settings adjusted?
    Here’s one of my projects that I need help cleaning up.
    Any help greatly appreciated.
    MAIN-PRGM TRACK SWITCH V 2.0 - .kicad_sch (58.8 KB)
    MAIN-PRGM TRACK SWITCH V 2.0 - .kicad_pcb (120.4 KB)
    MAIN-PRGM TRACK SWITCH V 2.0 - .kicad_prl (1.3 KB)
    MAIN-PRGM TRACK SWITCH V 2.0 - .kicad_pro (13.6 KB)
2

OK.

It looks like you drew the PCB manually.
To avoid errors, don’t do that.
Fix any errors in the schematic, and then “Update PCB from Schematic.”

Then use the rats nest lines to route your traces.

On the Schematic, don’t route the lines through the switch symbol. That’s really ugly.

image
image603×618 8.11 KB

1 Like
3

There’s also some database issue with your switches - the browser shows 2, but only two appear on the schematic.

Also, fully annotate your schematic. Every symbol needs a unique name. “2K” is not a name - it’s a value. R1 is a name.

4

They are NOT connected, If you zoom in, you’ll see that most of the tracks fail to connect to the pad, and that’s because your nets are *%#ed, and that’s because your schematic is *%#ed; there are ERC errors you have to fix first before updating the PCB; garbage in garbage out. If the nets are correct, there will be ratsnest lines between pads on the same net and finishing off a track will easily connect instead of “resisting” (sorry).

Read this FAQ by jmk: KiCad 7 & 8 Beginners Guide to Personal Symbol and Footprint Libraries

Same as for Q1, your nets are incorrect, so the tracks “resist” connecting.

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5

I think you mean that the PCB was drawn without using the schematic to first define the netlist. (??)

6

Some of the pads have net names so maybe F8 was used.

7

I had to look up “F8”. Of course I will often update PCB from schematic, but I use the menu command.
This happens much less often than I will move or rotate for example. And for those shortcuts, I get a bit confused between KiCad shortcuts and those for LTSpice. I think that LTSpice needs CTRL-R while KiCad does without the CTRL. Just hitting the R in LTSpice gives you a resistor. This is enough to drive me nuts. Cashew! Gezundheit. :crazy_face:

8

You also have duplicate symbols, like 2 x J4

9

Hi,

  1. I have a project that has some problems with the footprint I made for sw1 and sw3 which should be identical.
    SW3 pin 3 shows PTH pad3 AND PTH pad4? You can see the rats’ nest multiple connections.
    The footprint for SW1 doesn’t have this issue. I don’t know how to fix this.
  2. I originally drew the schematic with only the SW1 circuit. I needed two of these and then thought of making it one PCB with two circuits on it.
    I want to make the 12 VDC input ONE connector, and I am not sure what would happen with the PCB if I altered the schematic to make J1 and J5 into just J1 and did a UPDATE PCB FROM SCHEMATIC.
    I want to do the same thing for the PCP, making J3 and J8 just J3.
    I attached the files, and any help is greatly appreciated.
    MAIN-PRGM TRACK SWITCH II - .kicad_sch (58.9 KB)
    MAIN-PRGM TRACK SWITCH II - .kicad_pcb (125.4 KB)
    MAIN-PRGM TRACK SWITCH II - .kicad_prl (1.3 KB)
    MAIN-PRGM TRACK SWITCH II - .kicad_pro (14.2 KB)
10

Your footprints for SW1 and SW3 are faulty. SW1 has pad 3 and an extra pad 4 stacked up. SW3 has two pad 3s stacked up. Now it’s not an error per se to have more than one pad with the same number but it isn’t what you intended. Also pad 1’s copper ring is too thin and liable to peel off with heat.

PS: The Footprint Editor has a checker too that would have caught the errors.

11

I don’t completely understand what you are writing, but my guess is you want to feed a second circuit from the same 12V source. So you are thinking of copying and pasting the circuit to create a second copy, then rename the J5 there to J1.

This will not work. You cannot have duplicated reference designators in a schematic. They have to be unique. This is non-negotiable.

If you want to feed the second circuit from the same 12V, just run wires from the second circuit to the one 12V connector. In other words there is a second copy of every component except there is only one of the 12V connnector.

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