Generating Logic Components (e.g. quad Gates)

Libraries
1

Hi,
there are some requests around for 74xx parts and alike.
74xx and 40xx series have each the same layout for fundamental gates.
I considered creating them manually, maybe 10 components for each series (2-input, 3-input, …) and 2-4 devices each (DIP, SMD).
Or getting in touch with automating the component creation = collecting symbols.

A generic “logic gate (quad)” does not make that much sense in mho.

Do you think this is worth the effort?

2

to clearify:

74xx 2-input (quad) have A1, B1, Y1, A2, B2, Y2, … pin layout
40xx 2-input (quad) have A1, B1, Y1, Y2, A2, B2, …

3

Hi i9e1,

maybe I don’t understand, but is any problem to create a symbol for logic gate?
Next, the newly created devices (74xx or 40xx) will be a these symbols connected (as component) with physical package.
Ex:
7400: 4x symbol of the 2-input NAND gate + Power pins symbol, connected in the component: 74LS7400.
CMOS 4011: 4x symbol of the 2-input NAND gate + Power pins symbol (same as previous), connected in the component HEF4011.

Finnally: two device created with using two symbols (2-input NAND gate and power pins)

Or somethinghs is out of my thinking? :slight_smile:

Small example.

4

I tried LibrePCB because Kicad was driving me crazy.
I like the way LibrePCB works, but its lack of components in the supplied libraries is a showstopper. Users want to quickly pull down components to put in schematics, not spend all their time creating libraries of common components.
For it to have been around for so long and have so few common ICs in the libraries is very poor.
Sigh… back to Kicad.

5

Sad to hear :-/ Generally creating personal library elements doesn’t cost a lot of time (most time-consuming are footprints, but we already have a lot of them in libraries) so in my opinion the advantages of LibrePCB overweight this drawback. But my opinion might be biased :wink:

As an alternative it’s also possible to import Eagle libraries but generally I really prefer creating them from scratch…

Also I keep a list of library elements which are requested, so if you have concrete things missing you could let me know so I put them on the list.

6

Thank you for your response.
It might not take you long to create a library element, but for me coming to it new, it is a lot more time than just adding an existing element to a design.
The disadvantage of personal libraries is that they aren’t automatically available to others with whom a sketch is shared.
I play with ESPxxx devices, not too many in your library, and I’m using an MC4030 in a door-open detector (with an ESP01). No 4000 series chips in your library.
(Ironically Kicad has lots, but as single gates, so I ended up grouping four gates in a box to give an IC-layout view.)
Ken.

7

OK thanks for the info. I’m convinced our libraries will grow but it takes time as it is a huge effort.

Still I’d like to motivate you to try creating library elements :slightly_smiling_face: Once you understand how it works, it’s really an easy thing (IMO much easier than with KiCad!) and gives you a lot of power and flexibility for future projects. Sooner or later you’ll require to do it anyway as no EDA tool on this earth has a 100% complete library.

But of course I agree that shared components are preferred.

8

Wait, what? How?

9

Create a local library and open it in the library editor. Then File → Import → Import Eagle Library.

10

I just want to say, it’s been 2 years since this thread, and there hasn’t been any official adoption by any of the major manufacturers in LibrePCB.

I really like the software, and it’s far more intuitive than KiCAD or some of the other EDAs. That said, without support from manufacturers through official libraries, it’s a hard sell.

Even if it were only support via aggregate libraries like ultralibrarian.com, it would make this far easier to adopt.

11

I understand that newcomers are initially worrying a lot about the libraries, but honestly I think it shouldn’t be a reason for switching to another EDA tools for various reasons:

  • You can import KiCad or Eagle libraries, so you get thousands of parts in a few minutes (though the quality may vary, it is usually good enough for hobbyists)
  • You can create new parts by yourself. It may take a moment to understand how that works as it looks a bit complicated at first. But once you understand the workflow, it is really not hard to create your own parts - much easier than in other EDA tools because reusing existing symbols & footprints from our official libraries is a core feature of LibrePCB.

(but of course this isn’t an excuse to extend our libraries - we do have to add more parts to our libraries)

That is something which I do like to implement in future. It just takes time…