Can't connect pads

Hi, I only started using KiCad a couple of days ago. I’m trying to route a track between pads but for some reason it doesn’t let me connect it to anything. If I do it the other way around I get the same problem.

KiCad knows (or should know) what connections to make from the schematic, which is coupled to the footprints on the PCB via the netlist.

Each net in the netlist gets a name, and this name is printed under the pin number.
It’s a bit vague, but the small scribbles under the numbers “21”, “22”, and “23” are the names of the nets which those pins are a part of.

Your diodes do not have those scribbles under the pin numbers:

And this means there is some error with the netlist which has to be fixed first.

According to the datasheet:

the LTW-150TK is a small SMT Led:

… and it only has two pins. This does not match very well with what I see on your PCB.

On the top of this forum there is a very unobstrusive link to the FAQ . The FAQ of this forum has a lot of detailed articles about a lot of subjects in KiCad and is currently the most up to date written tutorial.

This may be a good start for you:

Is there any workaround I can do? I already updated the footprint and I’ve spent a lot of time with the design

You need to edit the linked schematic so that it correctly shows what you want. The schematic should have the correct connections between device reference designations and pin numbers.

BTW I do not understand how Paulvdh knew about you using LEDs, etc. But this is besides the point.

The value of the component shows as “LTW-150TK”, type this in the search engine of your choice (e.g. Octopart) and you know what component we are dealing with :wink:

I solved it by getting rid of the existing net in the source pad. Thanks to everyone who replied and pointed me in the right direction :slight_smile:

You have not “solved” it correctly.
The problem is not in the PCB, but in the schematic.
The connection between your IC and the LED’s are not properly made in the schematic, and therefore KiCad won’t let you make the connection on the PCB.

Can you post a screenshot of your schematic that shows the connection between one of the LED’s and your module?

I assume there is something wrong with the pin numbers, and pin numbers of LED’s are normally not shown on the schematic.

You can show such a pin number by clicking on it.
Here I clicked on pin number 2 of an SS34 diode:

Yes. If you insist on overriding the schematic then KiCad will be working against you instead of helping you. The result is likely to be more time fighting with the software, and more errors.

One thing that I like to do is to assign a lot of my own netnames (even when the net is not going anywhere else). I find that many of the KiCad assigned netnames are meaningless to me (such as pins 1 and 2 on a resistor). So I might change a name to “D7 cathode” which will be more helpful to me as I am routing the tracks.

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