THIS IS AN OLD TUTORIAL…
It is still here, in case it reaches parts the others don't. (But bits may be dated, or even wrong!… it doesn't get a lot of attention today.)
New and better tutorials on schematic symbol (aka ".lib files… though they are not the only "libraries") and footprints (aka "modules")
Go to the site's tutorials menu, look in the "Custom Schematic Symbols and Footprints" section, for the links to the newer, better tutorials.
(remains of the old tutorial…
Sometime before KiCad ver 4-0-4, a major re-design of how the definitions of footprints are stored in the system. Previously… and at the moment, this essay is couched in those terms, footprints were stored in .mod files, which could be in the folder of your choice. AND a .mod file could hold the definitions of several footprints. Since those "simple" days, there's been a change. Now each footprint gets a file to itself, with the .kicad_mod extension. And those files must live in a folder (or folders) with ".pretty" in the name, e.g. MyFootprints.pretty.
(The files holding schematic symbol definitions, the .lib files (NOT the only "libraries" in the system) operate in 4-0-4 as they did when this essay was written. Whew!)
Also… terminology: In the "old days", we spoke of "components" and "modules".
Today (Kicad vers 4-0-4) we tend to say "[/co1schem schematic symbol" where previously we said "component". Although you will still see "component" in some menu items.
And we say "footprint" where of old we said "module".
Making your own schematic symbols and footprints
Once there was a hermit who lived alone, high in the Himalayas. One Decemeber, a landslide near the hermit's cave killed a 800kg yak… And the hermit Ate the Whole Thing. How can one hermit eat a whole yak?
A little bit at a time. (I did say that the yak died in December.. free cold store, courtesy of Mother Nature!)
Don't try to master "all" of KiCad at once
I'm self-taught. (And it was no fun, I can tell you!)
You have the benefit(?!) of this website. If you will be patient and diligent, in the long run you will "get there" faster for building your knowledge a bit at a time. I've set out a program of study for you which builds brick on brick, a little bit at at time. (Forgive the mixed metaphore, but: Chew carefully. (The bits of yak, not the bricks.))
I you are getting stated with KiCad, you don't need to do your own components and modules yet! Start with the core issues, which are covered in the introductory exercise. If you are "a KiCad expert", you should be able to fly through that…. but along the way we will get "on the same page". Then, do the stuff on the main menu page about creating new schematic symbols and footprints. Only if they are insufficient do you need to come here.
This page has been checked to see that confusion in my brain (before 9 November, 2011) about the roles of pin names and pin and pad numbers hasn't led to errors here. I have a page with more on this if you are really curious.
Making your own components and footprints
Have you read the the introductory exercise? If not, please at least check out the "encyclopedia" entries for….
You may very well save yourself a lot of wheel spinning!
(I do not (yet) know of any difference between footprints and modules.)
The Happy History of Harry Hobbyist
Harry was a very lucky guy.
When he started with KiCad, all he wanted to do was make a simple circuit, and then a PCB for it. It had a connector for a battery, a resistor, a switch and an LED… just exactly what I show you how to do in the the introductory exercise, funnily enough.
Harry then said to himself…
"Hmm… that's pretty good. Everything I've done is fine.
"When I made the PCB, I had to cheat a bit, because the pins on my switch were not spaced quite the same way as the pads provided by the footprint which came with KiCad, the footprint used to complete the introductory exercise."
Everything else from the introductory exercise is just fine. Here's a tutorial on creating a new footprint.
Harry then embarked on another project. This time he needed to make a custom component. Happily, that wasn't much different from making a custom footprint. Furthermore, just because he needed a new component didn't necessarily mean that he also needed a new custom footprint, but even if he did, he already knew how to make one!
(MORE TO COME… multi part devices, next, maybe? What do YOU want done next? I can't do everything "first".)