Assign symbol from pcb editor

I want to use this
which might update my schematics from the pcb

the problem is that my new stuff from the pcbeditor, has not assigned symbols, so is there an easy way to do it within the pcb editor?


You cannot assign symbols to footprints with Kicad.
The kicad workflow is : Start with symbol, assign footprint to symbol, assign 3D to footprint.

I have used update-schematic-from-pcb almost never. There were a few times where I changed ref-des for a better id of jacks on the board or such, and then, yes, update-schematic-from-pcb propagates that back into the schematic – but the symbols were already in the schematic.

I can think of zero use-cases where one would ever put a footprint of a component on the pcb first.

One other time when I add directly to the pcb is when I create an array of boards. I first get the single-board schematic and layout finished – this is the master schematic and layout. Then I copy this to a new project-xxx-ARRAY, and replicate the board to create the array. At this point the schematic means nothing to me as it is just a pcb getting final touches for fab. I still need to manually add fiducials and tooling holes to the array frame in the pcb editor. That is the main use-case I have for adding something directly in the pcb editor. Another example are a few times where I plop a silk or copper symbol logo into the pcb. In none of these cases is there a need for update-schematic-from-pcb.

Fiducials, mounting holes etc. are available as symbols, if you ever want them on the Schematic.
They are located in the Kicad library “Mechanical”.

On a typical schematic I have an “other” page which is where I stick mounting holes, fiducials, and other oddball symbols that complete the project. They are generally not circuitry, with the exception of PTH holes that can connect to ground or something.

I was pointing out that for the case of a board array, I add holes and fiducials (directly in the pcb editor) to the array frame, and in that case they don’t get added to the schematic, nor is there any need update schematic from pcb.

Hi @teletypeguy

My comment was aimed at the OP, but I forgot to use @randomuserdamnit 's reply button :slightly_frowning_face:

Sorry about that.

1 Like

in my use case, I am “cloning” a pcb since there aren’t any out in the market
it would have been easier to trace components within the pcb editor, and then from there build up a schematics
yes you can do the opposite thing, but I find it easier to track everything from the pcbeditor, rather than using the symbol editor

KiCad is not primarily designed for reverse-engineering PCB’s, and it is built around the workflow of drawing the schematic first. In KiCad, it is putting a symbol on the schematic that defines a “part”, and links to a footprint is also attached to a schematic symbol. You can put a footprint directly on a PCB, but if you do so, it is just a footprint.

KiCad works quite well with a dual-monitor setup. Then you can have both the schematic and the PCB open at the same time, and next to each other, so both are visible. Then, switching between the schematic and PCB editors becomes trivial. I sometimes make use for this, for example when routing I/O pins of an uC to a connector. Then I first draw the PCB tracks from the uC to near the connector, then go back to the schematic and make the connections in the order that suits the PCB layout, then update the PCB from the Schematic and make the final connections to the connector.

Also, are you aware of PCB Editor / Place / Add Image? With this you can add a picture (or more) of a PCB to the PCB editor, and this is a quite significant boost for reverse-engineering a PCB.

1 Like

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