Stop press!
This page is OLD. From about 2011. And it is done using an old KiCad. If you haven't already seen the "modern" (Feb 2017/ KiCad 4-0-4) versions of my attempts to help you master creating custom schematic symbols and footprints, work through that first.
Having said that, here's the old material, lightly tweaked…
(This page continues the story of making your own schematic symbols)
The OLD (before 2/176) version of that story, of which this is a part, began 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.
Start eeSchema
If no project is currently open, first open one, then start eeSchema.
How you then set up a new schematic symbol libary with at least a "starter" schematic symbol in it as things were at 2/17 (KiCad 4-0-4) have been explained in a new tutorial. Go to the tutorials menu to get link (I have removed the old way to do that from here.))
At this point, we are about to create a new schematic symbol.
Start up the Library editor
NOT (yet) in the 2/17 tutorial is "stuff" about starting a schematic symbol from scratch. Here's a barely edited account of how that was done in 2011….
The schematic symbol editor used to look something like….
… don't be confused by the title at the top of the window which said ( before 4-0-4 "Component library editor", now (4-0-4) says "Component Library Editor".
Start a new component
These instructions were once for starting the first schematic symbol in a library. We now do that differently. And for making subsequent schematic symbol, it is often best to load something close, and then tweak it, save it under a new name.
But there was some "stuff" here, in the old (before 2/17) version of this, that I didn't want to throw away. So, for now perhaps of not very much use, but I present a not- very- well- informed essay on creating a schematic symbol from scratch. The illustrations are for an old (bef 4-0-4) version of KiCad.
To start a new component from scratch, you click the component editor's "Create a new component" button…
That should give rise to….
You must give it a name. The naming of components is something that I think even the broader KiCad community has trouble with. This is the name by which you will select the component from lists. It must not have spaces in it. It will accept upper and lower case letters… in the Windows version, anyway. Keep the names short and sweet, and especially while you are finding your feet, try to pick names which….
*You will recognize as "yours"
*Won't clash with "standard" names.
I am tending to prefix the names of my components with Atkb-
The "A" puts them at the tops of lists. (In some places, "a" comes after "Z"… the case matters… in some places.)
The "tkb" part is my initials. If my name were Lawrence Edward Daglish, I would have to think of some other "answer"!
You may want to set the "default reference designator" at this time, too. Think about good circuit diagrams you have known… the resistors are identified, R1, R2, R3…, capacitors C1, C2, C3… relays RLY1, RLY2… etc.
If you were creating… can't think why you would, but IF you were creating a new component for some sort of resistor, you would put "R" in for the "default reference designator".
For simple devices, you want 1 for "parts per package. A 7400 would have 4, because it is one chip with 4 NAND gates in it. The component in such cases is the symbol for just one of the gates. (Multi-part packages are a bit advanced for this essay. I will try to write about them separately, later. The also tend to have an invisible pin or two, again, a topic for another time!)
For now, leave everything else as in the screenshot above.
Put a pin on the "page", near the center, where the blue lines cross. Every component (that I can think of!) will have at least one pin. Pins in components map to pads in footprints, as, much later, you will see. The mapping is based on the number of the pin and the number of the pad. (Be careful that you don't… as I do, regularly… confuse what numbers do vs what names do. And add to that area for care distinguishing the names of components from the names of their pins!)
To put a pin on the "page", be sure the "Add pins" button near the top of the right hand toolbar is selected…
Move the crosshairs to where you want a pin, and click. That should give rise to…
(I've chopped the bottom off of the dialog.)
You must give the pin a "number", unique in this component. For the moment, number the first pin "1", the second pin you create "2", and so on.
A little "Gotcha"…. Sometimes the value for "length" gets changed to zero, which results in a pin you can't see! (Which isn't, by the way, the same thing as an invisible pin!)
Before long, you may want to use things like "Gnd" for a pin's "number". This is allowed… but you may regret "being clever". Go with using strings of digits for pin numbers for now. (You are not allowed more than 4, by the way.)
You do not have to give the pins names at this stage, nor do you have to change any of the other things you see in the pin properties window. As you learn more, you will want to do more… but those other things, and indeed even the number, can be changed later.
One thing you may soon want to change is the pin's orientation. After it has been placed on the page, if you have the pointer button at the top of the right hand toolbar selected, then just put the cross hairs over the pin you want to rotate, and press 'R'. (You can move pins in a smilar manner, by pressing 'M', moving your mouse, and then clicking, to "drop" the pin in a new place.)
All we need for the moment is a single pin numbered "1".
Save the component
Easily done I hope. It is if you got here by the route I hope you were taking. As this page's future is not long, I'm skimping here. Sorry!
Just click the link to go to the next page in this tutorial on creating new KiCad components…..
The page you have been reading is a sub-page of the "Making Components and Footprints" section of KiCadHowTo.com.