November 2, 2026

KiCAD - IDC hell

My first schematic was finished -- or so I thought. I was lucky to catch a significant mistake before sending it out.

I have a ribbon cable to a DB-25 connector. That ends up being a 2x13 pin 0.1 spaced (2.54mm) IDC header on my schematic.

The trick is pin numbering. You want the pins to number all down one side, not all even on one side and all odd on the other. The component is offered in both styles. For this connector I want Conn_02x13_Top_Bottom, not what I originally selected (Conn_02x13_Odd_Even).

This allows me to get everything fixed in the schematic, but now I seem to be unable to find a footprint that corresponds to this order!

I select "Connector_IDC:IDC-Header_2x13_P2.54mm_Vertical" and the schematic is happy, but the PCB shows even/odd numbering. I can't find a footprint that does what I want.

So I use the footprint editor and change the number on each and every one of the 26 pads. I type Ctrl-S in the footprint editor to save and then go back to the PCB editor and I see what I want!!

Then I get busy and re-route everything.


Have any comments? Questions? Drop me a line!

Tom's Electronics pages / tom@mmto.org