Footprint for MAX233


#1

I couldn’t find the MAX233 so I created my own schematics. Now I need to assign it a footprint. Obviously, there are many 20 pin chips so I probably could just take one. However, is this bad practice because after all all the labels will be incorrect? If it’s not good practice, then is there a way for me to import an existing footprint, change the labels and save it as a new footprint?


#2

Footprints only have pin numbers. You should be able to use a standard footprint


#3

You’re right, it seems only the pin numbers matter at the end for designing the PCB. During PCB design the graphics seem to come from the footprint but they won’t end up on the PCB. The labeling, interestingly, seems to come from the schematics which is a good thing. And I guess it can still be changed. Hence, I ended up just using some generic DIP. Thanks!


#4

[quote=“mulu, post:3, topic:9120”]
only the pin numbers matter at the end for designing the PCB. [/quote]

Look at the old post: Linking Pins to Pads to confirm this concept.

I think you have grasped the basic concept, but don’t hold onto it too tightly: a non-standard footprint may surprise you. Have you opened any footprints in the Footprint Editor? I recommend that you do so, and spend a little time poking around in the various layers (with other layers not displayed) to see what information is in there.

The KiCAD Library Conventions ( “KLC” ) as well as several threads on this Forum discuss the information, values, reference designators, etc, that should be found on the various footprint layers. The KLC is worth at least a cursory reading. I suspect that most of us who maintain our own libraries are systemically at odds with KLC at some point or other but it’s still an invaluable reference for designing your own footprints.

(I have worked in technical positions for half a century. I have learned that every time I re-invent a wheel, I need to make sure I file off all the corners. Or at least as many as the last guy filed off his wheel. KLC shows you where some of those corners are hiding.)

Dale


#5

Actually, I previously created my first footprint for an Arduino Nano for which I could not even find schematics. I will take a look at the KLC. Thanks for all the info.

As for re-inventing the wheel, is there a place where you can submit your schematics/footprints, ideally they will be reviewed by somebody and then added to the standard library included with KiCad. For instance for the Arduino Uno, I am sure many others have already created it themselves so if I could submit mine then others don’t have to re-invent it in the future.


#6

[quote=“mulu, post:5, topic:9120”]
is there a place where you can submit your schematics/footprints,
[/quote]Github and do a pull request. I’m not a user myself so others can probably guide you in that.


#7

That’s the legacy repo.
The new repos are:

For symbols: https://github.com/KiCad/kicad-symbols
For footprints: https://github.com/KiCad/kicad-footprints


#8

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