Conn_02x16_Row_Letter_Last no similar footprint?


#1

I’m using a nightly from a few months ago. see below.

I rarely use dual row connectors, but need to for a small backplane. From the schematic lib I chose:
Conn_02x16_Row_Letter_Last
as this type of numbering is easier in this case. Pin numbers are:
1a 1b
2a 2b

When I go to find a matching footprint, conn pinhead 02x16 all of the footprints have pins labeled 1-2 3-4 so nothing is hooked up in PCBnew.

Guess I need to copy that footprint and renumber it by hand. Is that the plan?

Application: kicad
Version: (6.0.0-rc1-dev-1289-g6d8ca311f), release build
Libraries:
wxWidgets 3.0.4
libcurl/7.61.1 OpenSSL/1.1.1 (WinSSL) zlib/1.2.11 brotli/1.0.6 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) nghttp2/1.34.0
Platform: Windows 7 (build 7601, Service Pack 1), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8)
Boost: 1.68.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.61.1
Compiler: GCC 8.2.0 with C++ ABI 1013

Build settings:
USE_WX_GRAPHICS_CONTEXT=OFF
USE_WX_OVERLAY=OFF
KICAD_SCRIPTING=ON
KICAD_SCRIPTING_MODULES=ON
KICAD_SCRIPTING_PYTHON3=OFF
KICAD_SCRIPTING_WXPYTHON=ON
KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
KICAD_SCRIPTING_ACTION_MENU=ON
BUILD_GITHUB_PLUGIN=ON
KICAD_USE_OCE=ON
KICAD_USE_OCC=OFF
KICAD_SPICE=ON


#2

Mandatory reading: How does KiCad know which symbol pin is connected to which pad of the footprint?

Connector footprint pads are numbered as defined in the datasheet of the connector. Meaning if the connector datasheet uses 1-2-3 then the footprint will use the same numbering scheme.

The reason there are different numbering schemes present in the symbol lib is because different connector manufacturers use different numbering schemes for their connectors.

The way to choose a particular symbol for a component is by looking in the datasheet which numbering scheme is used. This ensures that the datasheet, symbol, footprint and markings on the connector agree with each other.


In the case of pin header there is not really a definition given in the datasheet. As far as i am aware there is however a kind of standard way these are normally numbered. They use one row for all the even pins and one for the odd pins.

This might be the case because flat cables are often connected to such parts. Such flat cable connectors are physically build such that odd numbered leads end up on one row and even numbered ones on the other. (Yes i know shrouded headers are normally used for such cable connections. But they are similar enough to each other such that it makes sense to use the same pin naming scheme for both.)


#3

Rene,
Thanks, I understand about the agreement of schematic to pcb to actual component. And I agree that pin headers are a huge grey area with RPi style numbering prevalent.

However, finding the symbol using letter-last, I then expected to find a corresponding footprint with letter last. It is not a huge deal for me to clone and renumber, I’ve done it already. I just felt others might fall in the same hole.

Barry


#4

You are looking for something like the DIN 41612 connector numbering
These used to be in https://github.com/KiCad/Connectors_IEC_DIN.pretty


#5

What I really want was a 2x16 header male & female with pins 1A-1B, 2A-2B. There is no COTS connector with integral pin numbers with which to conform.

I just took the standard lib parts, copied them and relabeled the pins using a text editor. No big deal. Thanks all for the comments.