Noob Q... update footprint

[Bo_Herrmannsen]

So i imported a board an schematic from eagle with the 2017-12-24 revision 570866557 version

i even used some gerbers to get all components in approx where they should be

I have 5-10 components left and found out that a few has the wrong footprint. Sure enough in the schematic the symbol is wrong. I delete the component and dublicate another and change the ref from ? to the one i just deleted

on the pcblayout it does not update the foot print like i would have expected… hwo do i get the footprint updated ?

from what i can see all components are stuck in an lib that was created during the import

[Bo_Herrmannsen]

might not be the correct way but on the pcb i dublicated a component with the right footprint and changed the designation/ref to the correct one

[Rene_Poschl]

kicad has no automatic communication between the schematic and the pcb part of the program.
You need to export the netlist from within eeschema (after making your change)
And then import the netlist into pcb_new.

In the import dialog you have a few settings that will determine what happens. Play around with them a bit.

[Bo_Herrmannsen]

thanks, but i cheated a bit… i copied something that had the correct footprint

[Rene_Poschl]

Did you copy the symbol in eeschema or the footprint in pcb new?
The normal workflow would be the former. (The later is not a good idea because then the schematic and pcb side are out of sync. This will lead to strange problems.)

If you did the former, my comment above applies.

[Bo_Herrmannsen]

i copied the symbol in schematic and then copied footprint in pcb new

how can they get out of sync when there is no communication between the 2?

[hermit]

PCBnew picks up information created by the netlist in the schematic portion. When you read the netlist in you are given some options like changing footprints already assigned or using new ones assigned in the netlist. There is no automatic communication but there is obviously some communication.

[Bo_Herrmannsen]

well i tried to read the net list and it was to confusing… guess i’m just a tad to stupid to get it

another thing… where in the schematic symbol lib do i find a 2.54 pitch 3 way pin header? trying to find that too but so far no luck

[hermit]

There is a pin_header lib. I just checked. Make sure it is installed.

[Rene_Poschl]

@Bo_Herrmannsen

where in the schematic symbol lib do i find a 2.54 pitch 3 way pin header

well the symbol you will use is the generic conn_01x03 symbol and you connect it to the correct footprint. (via the footprint field)

Have a look at these two faq entries that give more details about footprints and symbols and how they are connected. (click on the links to read the full post.)

What is the difference between footprints and symbols?

What are symbols Symbols abstract the function of a component and communicates the interface of it to both KiCad and the person reading the schematic. To to this it at least needs to define the connection points for the schematic with so called pins. It is suggested to add some artwork to the symbol to do this effectively. The easiest symbol is a so called black box symbol. It simply surrounds the symbol with a box with every pin having a meaningful name shown. For some symbol classes there a…

How can i assign a footprint to a symbol?

Disclaimer: Screenshots taken from version 5.1.4 KiCad determines which symbol belongs to which footprint via the footprint field of the symbol. This symbol field can be set either already in the library (fully specified symbol) or sometime during the schematic design process. This tutorial lists all options you have to assign a footprint to your symbols. At schematic design time This workflow is less work for library maintenance and allows for selecting exact components late in the design pro…

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You can also watch some video tutorials. I can suggest the tutorial series getting to blinky. https://contextualelectronics.com/courses/getting-to-blinky/

[dchisholm]

@Bo_Herrmannsen

might not be the correct way but on the pcb i dublicated a component with the right footprint and changed the designation/ref to the correct one

If I understand your explanation correctly, this is a process I sometimes use. I change the footprint field for a schematic symbol; then change the footprint (delete the old footprint, and place the new footprint) in PCBNew; then generate and import the netlist in “Dry Run” mode. If the netlist import shows no errors, I know I got it right.

Dale

[dchisholm]

@Bo_Herrmannsen

well i tried to read the net list and it was to confusing…

Can you say more about what was confusing?

The “Dry Run” option in the netlist import dialog is especially useful to me! I disable the “Info” notifications, leaving the “Error”, “Warning” and “Action” messages. These tell me if the new netlist has the changes I expected, before I commit to importing the netlist “for real”.

Dale