New user, can't route tracks

Hello there,

I’m a new user without hardware development experience. I want to build my own mechanical keyboard. I used this awesome tool to generate a base PCB design but it doesn’t have the wires connected.

I attempted to do it, but as soon as I click my mouse, it disappears. I’m not sure if it is because the wire is too close to a whole or something? Or do I need to create another layer?

please help me. Thank you very much!

Does this PCB generator also make a schematic (and netlist)?

I see a few net names such as “col0” and “col1” but the connections on the pads you are drawing a track to are too small to see in your screenshot.

Can you draw a track from pin 1 with label “col0” from the upper left key to the pin with the same label on the second row?

Having a proper schematic and the links between the schematic symbols and the footprints on the PCB is important for KiCad to work properly.

There are also some very strange pads. Looking closely; those pads labelled “2” are made of two overlapping pads. Same with pad “1”. Also, lots of “2” pads.

The two overlapping holes in some of the “2” pads can indeed be a problem. Holes can not be drilled properly halfway through another hole and drills break easily in such situations. This can be enough reason for a PCB manufacturer to simply reject your design.

Having multiple pads with the same number is quite common though in KiCad, but there is no consensus of how to handle them. The current implementation is that pads with the same number always have to be connected by copper tracks, while in keyboards switches and buttons it’s common to have “wire bridges” built into the switch itself, so a layout of a keyboard matrix can be made easily on a single layer PCB.

My guess is that those overlappings are intended, because there are a few different types of keyboard switches, the tool author might want to create an universal pcb to support any type.

for example, in this tutorial,

the PO also created overlapped holes to support different keyboard configurations.

this is my theory, I don’t know.

Hi, @shi-yan

I really think, as @paulvdh comments, you need to use the Kicad workflow to make your board.
Start with a schematic, draw and assign footprints to your symbols and then use your downloaded tool as a guide to position your footprints on a PCB.

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These are all right:

This is also OK:

The pads may overlap, those are just etched in copper.

But the hole below is not OK. Here the holes themselves overlap, and that is what causes drills to break and PCB’s to be rejected by some of the manufacturers.

So, how about the schematic? Do you have a schematic that is properly connected to the PCB?

@jmk are you talking about this schematic? this is also generated.

The reason I dont want to start from scratch is that I don’t know how to perfectly align the keyboard plate with the pcb. (i.e. how to perfectly align keyboard switch holes). for a keyboard precision matters.

I did a screen recording of what’s happening on my side:


as soon as I draw a line, the line disappears

OK, so you have both a schematic and footprints on the PCB, apparently both generated by some script.

If you’re unfamiliar with KiCad, and you find the work up to now valuable, then first make a backup before you continue.

Now check the connection between the schematic and the PCB.
Do that with Eeschema / Tools / Update PCB from Schematic [F8].

Thank you, I tried it. there is an error saying there are multiple R3 units

here is the generated project file

Annotation must be done properly before the Update PCB from Schematics [F8] works properly, and a quick fix is to rename one of the resistors from “R3” to “R223”.

Your generated project is also incomplete. No wiring to the USB, and even Power and GND are not connected to the uC. You are probably meant to fix those yourself.

If you’re unsure how to do such tasks, then start with a beginners tutorial for KiCad. For example:

Thank you for the guidance, I will read the tutorial.

I hoped to get it downloaded and printed. but I guess I need to be patient and really learn how to use Kicad.

Based on this quick video, it looks to me like the tracks are there, but either you don’t know that you need to recalculate the zone (press the b key), or the track is the same net as the zone.

Thank you very much. After I pressed “b”, I started to see the wires. but they looked messy and started to delete them. That somehow made the board hollow.

Anyway, I guess I need to learn from the beginning. I have no idea what zone means.

so regarding the overlapped holes, I think my theory was correct. they are intended.

I found some info here:

The zones don’t recalculate every time you add a trace, remove a trace, or move a trace that intersects with the zone. You need to manually recalculate the zone with the b key. To avoid having to regenerate the zone all the time you can select the button in the left-hand tool bar to hide the zone fill while you work, letting you recalculate the zones only when you need to check connectivity (to make sure you haven’t cut off pads that want to be connected to the zone) yet still see what you are doing.

2021-09-25 01_40_08-Pcbnew — C__Users_chelliot_Dropbox_RemoteDevelopment_KiCad_KiCad5TestNewHierarch

There are some really well written FAQ entries on this site that you can access with the FAQ link in the right of the header bar of this website. But, that category isn’t well organized. One of the items there is an index of FAQ entries organized by category. You may want to bookmark this item so you can refer to it while learning.

The footprints in your project either aren’t from that GitHub repo, or are old versions. The screenshot that you provided have pins 1&2 swapped from your board. Never mind. It looks like the screenshot on the repo that you copied has pins 1 & 2 swapped by looking at the footprint source code. (In the source code pin1 is made of 2 parts while pin2 is a single oval pad with an oval hole.)

Also, it looks like pin 2 on your board are overlapping drill holes which most (all?) board manufacturers won’t like. But the latest footprint from the repo pin2 is an actual oval hole that many board houses are OK with.

I forget if the tutorials in the FAQ area cover best practices for replacing/updating footprints en masse, but I do recall it being discussed here on the forums. If you can’t figure it out, find it in the FAQs, or find helo with the forum search, ask and someone can help walk you through it.

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