Connector_Audio:StereoJack_3.5mm - odd pin numbering?


#1

Instead of pin numbers this symbol has letters so Pcbnew gives the following errors when reading the netlist:

Error: Component “J7” pad “R” not found in footprint “Connector_Audio:StereoJack_3.5mm_Switch_Ledino_KB3SPRS_Horizontal”
Error: Component “J7” pad “S” not found in footprint “Connector_Audio:StereoJack_3.5mm_Switch_Ledino_KB3SPRS_Horizontal”
Error: Component “J7” pad “T” not found in footprint “Connector_Audio:StereoJack_3.5mm_Switch_Ledino_KB3SPRS_Horizontal”
Error: Component “J7” pad “RN” not found in footprint “Connector_Audio:StereoJack_3.5mm_Switch_Ledino_KB3SPRS_Horizontal”
Error: Component “J7” pad “TN” not found in footprint “Connector_Audio:StereoJack_3.5mm_Switch_Ledino_KB3SPRS_Horizontal”

Sure enough Pin names are set to ~ while Pin numbers have leters:

“Connector_Audio:StereoJack_3.5mm_Switch_Ledino_KB3SPRS_Horizontal” is the footprint that I found that matches this symbol. I’m learning KiCad V5 so not entirely sure what to expect. If I edit the pin properties to show the correct numbers as per the footprint (and put the TSR letters in the pin names) it will all make sense to Pcbnew but the schematic symbol looks a bit of a mess:
50

What is the expectation for using this symbol?


#2

That’s an error in either the symbols or the footprints; not sure which was intended. But definitely one or the other needs to change.

I noticed this when I was filing a recent PR for a new audio jack footprint.


#3

ppelleti, it didn’t occur to me to edit footprint pad numbers into letters! That seems a bit odd but if that’s the “KiCad way” it would certainly make the schematic symbol more readable.

Bit of a blow for consistency though. I think the tension here is with defining symbols with “inner workings”. IC’s all have pin numbers on the outside and just a text label on the inside. If internal wires etc. are to be drawn then there needs to be a way to nudge the labels around a bit.


#4

Well, the KiCad 4 way was definitely to use digits. (Although even KiCad 4 allowed pin “numbers” to be letters, the official library didn’t use that capability.) With the KiCad 5 library, it seems that alphabetic pin “numbers” are officially allowed now. So I suspect that someone changed the symbols but didn’t change the footprints, but I don’t know.

I suspect the rationale is that different manufacturers of audio jacks may number their pins differently, so using alphabetic “numbers” means that the same symbol can be used with a footprint for any jack. But I’m just guessing; I don’t know the official rationale.


#5

It looks like issue #191 is where the alphabetic pin numbering was decided upon.


#6

Thanks, good spot. I don’t agree but won’t argue with their decision. For now I’m going to make a local copy of the edited symbol to maintain numbered footprint pads.