U type IC pins number


from what I understand the pins are counted in a U shape.
but what about this kind of ‘dual’ row on each side pins…


my spec sheet wont say much about pin # so I need to make my own.
am I doing it right ? I do two nested U shape for pins#…
meaning top left will have 1 and 21…


EDIT: also, what about schematic for those types of footprint ?
should I draw a single line of pins, make a special rectangle with all DIO pins near each others or … what…

With such unusual pin numbering, you should make a custom symbol and footprint with all 40 pins

1 Like

I would draw it to make it clear to yourself after you have been away from it for a few weeks / months,

1 Like

completely depends on you.
Can make multi part symbol or one big single one or one that even reflects the actual physical connector.
Whatever works best for you and people who have to understand your schematic.

I prefer method 1 or 2.

Would that module not use twin row header sockets?


1 Like

it should but it’s a dev board and the pins that are ‘inside’ are not populated with headers, but accessible if needed.

Since it’s my first ‘dauther board’ design I’ll make pins accessible on a larger board and make it fit in a Hammond enclosure.

The spacing on your PCB footprint seems to be off.
The rows probably all fit on a 0.1" grid.

In KiCad you do not really have to use pin numbers, but you can use any text string to map the EEschem symbols to footprints. They just have to match.
I believe that in V4.0.7 there is a limit of 4 characters, and that limitation has been lifted in V5.

If it is a one off project, I would probably simply use 2 of the 20 pin sockets as shown by slc.
If you are likely to use that component more often I suggest to make a full Schematic symbol / Footprint combo and put the outline of the daughter PCB on the silk screen.

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