KiCad 5 #11 Creating new Symbols

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This tutorial shows you how to create new symbols and add them to a new library.
This is part of a KiCad 5 tutorial playlist: • KiCad 5 Tutorial
Source files from this tutorial: github.com/joh...
Music used in this video (Vibe Tracks, Alternate) was downloaded from the KZbin Audio Library: www.youtube.co...
#kicad5

[@donaldwright2426]

You saved me time especially when you strongly recommended installing the footprint that already exists instead of editing and associating the footprint afterwards! Wow, that is a shortcut that everyone should be aware. Thank you!

[@JohnsBasement]

Yeah. When you only have one option it is a no-brainer.

[@ron.owensby]

Libraries is what I have had the most trouble understanding! On a side note (@18:15) it amazes me how many typos I find on datasheets and websites. You would think they would check there work a little better. Thank you, John, for the time you take making these videos.

[@JohnsBasement]

In this case, it might be a ligature rendering problem with my PDF browser. I too have seen MUCH worse!! It never ceases to amaze me how much of humanity's time is wasted due to horrible documentation. 😒

[@voytechj]

good tutorial. One advice: use more often INSERT key. It will autorepeat pin insertion and auto increment pin number and last number of pin name. So if you put pin 11, "PIO1_1" and hit INSERT you will gen next pin 12, "PIO1_2" for free. In my opinion pins should not reflect their positions in real package. Better group them by a function. Vdd pins at the top, Vss and the bottom makes less wiring in a schematic.

[@宏偉張]

can you explain how that works

[@宏偉張]

ok I already get it works

[@ThePetaaaaa]

@@cambouiscom Thanks for the interesting comment. I was about to ask what the reasoning is for not following the KLC with "power on top" and "GND at bottom" was. However, you made a valid point that having a 1:1 symbol can make PCB routing easier. With modern MCUs you can have many options for your e.g. DIO pins. Saves you the hassle to later swap pins in the schematic to avoid uneccessary routing.

[@TheMohsell]

Very, straight to the point !

[@JohnsBasement]

I'm gonna frame this in my office. ...I have some students that might beg to differ! 😂

[@f6fvy]

Regarding the value and reference positions, check the eeschema preferences dialog, and look for the "Automatic place symbol fields" checkbox (wording may vary - I'm using v5.1). To use the positions defined in the library, uncheck it. *BUT* be aware that further rotations of the symbol can be problematic for these texts. That's why the default is "automatic". Hope this helps.

[@JohnsBasement]

Thanks! I'll check that out!

[@lhoussainhamadi8414]

Thank you so much for this great content!

[@JohnsBasement]

You're welcome. I'm glad to be able to help.

[@TacianoCanassa82]

Amazing! Very useful! Thanks!

[@sagebrother]

Thanks for the video!!

[@JohnsBasement]

You're welcome!

[@scharkalvin]

On a large part like a processor, I'd put the U? and part value text INSIDE the box. You have room for it.

[@brucebarrett1273]

macOS tip... I had the worst time finding the create symbol library command / menu. Turns out you open the symbol editor, then look under the main "File" menu for "New Library..."

[@farhabunali8703]

Hello John, first of all thank you for these amazing videos. I just had a question regarding how to change the units when it comes to Pin properties...Despite clicking the upper left 'In' button and it being highlighted when I go to my Pin Properties, it still shows 'mils'. I was wondering how you were able to switch yours to inches. Any suggestions would help.

[@JohnsBasement]

Thank you for your kind words! My editor just shows the selected units type when it opens. I cannot change the units while it is open though (because the editor is a modal window/prevents the parent window from being used). I have to close it, change the units, and then reopen it. Keep in mind that the notion of the units buttons being 'hiighted' may not agree with your senses. I keep thinking that the selected units look like the button is disabled rather than selected :-/ When in doubt, select back & forth between the two types of units to get your bearings.

[@alexanderbecker4360]

I have a question. When you use more generic parts like BJTs or Mosfets do you tend to use generic symbols and then specify the exact type in the schematic or do you tend to create a separate part for such things. When you have ICs that are custom to a specific vendor and package it makes sense to have that information embedded in the symbol. Also it is seemingly possible to embed multiple variants of a part within one symbol (3 subvariants of a mosfet are combined in a single pin). One comment specific to this video there is a bidirectional pin type that is used for the pins you identify as passive. Bidirectional is used extensively in the standard kicad symbol library.

[@JohnsBasement]

If more specific parts are available then I would agree that using them would be a good idea. However, if you are tinkering and things change before you get to where you end up going then the specific ones might become a nuisance. Your design style should help you decide which way to go. As for pin types, I tend to favor using only the input, output, power and passive. In some cases it might be a better idea to be more specific. In the past the DRC rules could not be easily suppressed on a per-net basis. If/when that changes then I will likely be more accurate about pin specifics.

[@user001sg9]

Hi John, thanks a lot for your wonderful videos. I have a question regarding creating symbols in the global library - like you have shown in this video. It is nice and easy to create a symbol in a global library compared to creating it in a project-specific library. My question. isn't there a danger of losing all your self-created symbols placed in the global library if and when KiCad updates it's set of (default) symbols?

[@JohnsBasement]

No. There isn't ONE global library. Never put symbols in ANY library that isn't yourr own.

[@Berghiker]

My whole Timer library cannot open.

[@scharkalvin]

Came back with new question! I created some symbols and tried to use them, but wires don't line up with them. It's like the 'grid snap' is set to an odd interval between the schematic and the symbols. What am I doing wrong?

[@JohnsBasement]

I apparently had trouble getting out the REASON for using either the .1in or .05in grid at time 5:20 in this video. KiCad symbols pretty much all use .05in as their pin spacing. Therefore you have to set the grid spacing at .05in when editing your schematics or you can't click on anything. You /also/ have to make sure that your own symbols have a pin spacing that is a multiple of .05 (which therefore must be either .05in or .1in)

[@scharkalvin]

@@JohnsBasement Thanks for that. Now need to recreate my symbols to .05" or .1" grid snap. (Only have a half dozen so far). I suppose I could set the grid spacing in my schematic sheet to a smaller number, like .01" but that would make snapping harder unless I zoomed in to do it. Actually, I'm surprised that the default settings for the grid in the symbols and schematics wasn't in Metric.. Maybe it is if you use an "Axxx" sized paper, and in inches if you use US sized paper?

[@JohnsBasement]

@@scharkalvin That would be horrible too because any component on a US paper size would be unusable on metric paper. (Altium addresses this by letting the user mouse-click on existing endpoints even if they are off the grid.) By standardizing on a .05in grid for ALL components/parts and then using a .05in grid regardless of paper size will work and is not TOO bad a solution... as long as you know that you NEED to use a .05in grid when editing schematics. I tend to use .1in when creating parts and the .05 for schematics... because most other components are .05in. If you have something that was /placed on a schematic) using a higher res than .05 and thencan not select th part at all, use the mouse to draw a box around it to select it. Then you might have to just delete it and then replace it with another part at the .05 grid setting. I suspect this is one of the rites of passage/learning-experience of all new KiCad users. :-/

[@scharkalvin]

@@JohnsBasement I recreated one of the parts with .05", and it worked OK. I could have used .1" snap on symbol creation, but that forces me to make the parts larger than I'd like, I need to fit a schematic onto letter sized paper. Wish I had a printer that did 11x17" :-) I could compromise and use legal sized paper (8.5x14), though that means changing out the paper in the printer just to print a schematic (or hand feed one at a time).

[@JohnsBasement]

I do 11x17 and prent on letter all the time. Some times, however I need a magnifying glass though. 😕 When needed, I print final drafts at local library or fedex.

[@Berghiker]

How can you resize the symbol you just created?

[@JohnsBasement]

I just change the drawing to resize it. I find it easier to get the size right by putting all the pins down and arranging them first and then adding the yellow box for the component 'body'.

[@Berghiker]

Why do wires sometimes not snap to the component leads in Schematics?

[@JohnsBasement]

Not sure what you mean here. The ends of wires always snap to the closest grid point. If they are all over then change your grid to .05" (I'd prefer .1" but there are too many parts in the libraries that have pins on .05" centers.)

[@Berghiker]

@@JohnsBasement I use mm and it still does not snap to the circle on the pin. Tried all from 1mm to 100mm.

[@JohnsBasement]

@@Berghiker You have to use .05" for your schematic drawings if you expect ANY of the library parts to work for you. THerefore you also need to use the same settings when creating your own parts/components.

[@Berghiker]

@@JohnsBasement I see THAT is exactly the problem. I will try again. TY.

[@Berghiker]

Even using the browse function, I still can't find the netlist I just created. Where could it be?

[@JohnsBasement]

If you save a netlist file then it had to go somewhere. Look closer when you create it at what directory it ended up in. If you save it into ./blahblah.net then it is in the same directory as the project. If you are on Windows (and it hides all the filename extensions because somehow replacing obvious and simple names with icons that all look the same is supposed to he helpful?) AND the netlist has the same name as the project (but with a .net extension) then it is probably hiding next to the pcb, sch, and pro files.

[@Berghiker]

@@JohnsBasement I found it thanks. In the netlist window, Pcbnew, options: the default format was ticked. I unchecked it.

[@Berghiker]

@@JohnsBasement I now only have 4 errors.

[@Berghiker]

@@JohnsBasement I can't find my new symbols P1 and P2. It's not listed on my schematic either.

[@JohnsBasement]

Is your library listed as in the project or global library lists?

[@naeemshahzad3873]

IF YOU WANT TO CREATE SYMBOL IN 5 PART A TO E BUT WHEN I EDIT A IT EFECT ON ALL A TO E ..WHERE I AM WRONG DONT UNDERSTAN ?

[@JohnsBasement]

Did you click the 'All units not interchangeable' option? (It is in the Symbol Properties editor.) I discuss that in a different video on Multi-Unit Symbols in part 18: kzbin.info/www/bejne/l5KWZHqjmpmbr9U

[@naeemshahzad3873]

@@JohnsBasement Thank you very much . This video solve the problem ..

[@Berghiker]

The cache.lib failed to load. How do I resolve this?

[@JohnsBasement]

The cache.lib file is the set of symbols/components that have been used in the current project. It should be part of the set of files that comprise a project and in the same directory as the .pro file. If you got your schematic from someone else, ask them to give you the cache.lib file. (I can see that my project 2054 on github was missing a cache.lib file :-( I just pushed it up if that is how you got into this problem.) Another possibility might be that your cache.lib file is present but it has the incorrect permissions and/or ownership.

[@Berghiker]

@@JohnsBasement I think I changed the name by accident and now it can't find it.

[@JohnsBasement]

@@Berghiker ah!! Ofcourse! Rename it so that it is the name of the project followed by "-cache.lib" the project name is the name of the .pro file without the .pro

[@scharkalvin]

I once again ran into the idiotic assignment of a MosFet pin as "bidirectional". Technically correct, but it will fail the electrical rules check if connected to ground or power!! The only thing that works in all cases is passive. Same thing for BJT's come to think of it. Maybe putting a zero ohm resistor in series with the transistor lead would cheat the rule checker. When I get this warning, I just disable it by changing the settings matrix for the rule checker to allow bidirectional and power to be connected. For custom transistor libraries, I call the pins passive.

[@JohnsBasement]

Yeah. I lean toward 'passive' or 'unspecified' on things like transistors where any pin can be anything. There are SO many ways to use them that any one setting never made sense to me. If anyone has any tips on how to deal with per-pin DRC overrides I'd love to hear about it.

[@Berghiker]

Cannot open aliases from Timer Library. Why not? How do I resolve this?

[@JohnsBasement]

Not enough context to make sense of this question.