Best practice convention for multiple symbols representing the same part?

Schematic Library Symbols
#1

I am using the same PIC MCU in multiple projects, and find that I need to sometimes generate a different symbol for the same part, to show only the pins I’m using, to move pins to different sides of the symbol to make the schematic more readable and flow better, etc.

For example, I defined a PIC18F4620-IP, and then a PIC18F4620-IP-002 with a different subset of pins showing, and with some of the pins positioned differently in the symbol. Both describe the exact same part, they just present a different view of it.

I would like the symbols to appear as separate entities in the list of symbols, so that I can choose between them add more variations, etc., but I would also like to be able to have the label that appears at the top of the symbol in the schematic display the same name across all variations. When I tried to change the label text, it changed the name of the part, and thus collapsed two symbols into one in the list. So, that approach didn’t fly.

What is the best practice for naming symbols that are variations of the same part, without cluttering up the schematics that use them with suffixes/prefixes on the symbol name?

Thanks in advance for any guidance.

1 Like
#2

In the stable KiCad V5.1.x your best option probably is to make a project specific library, then copy the “standard” symbol to the library belonging to that project and then use and modify it to your liking.

In KiCad-nightly V5.99 a copy of the schematic symbols is saved in the schematic itself, and only updated from the library when you do it explicitly yourself, but even so, putting the symbol in a project specific library is of course also still possible.

1 Like
#3

I don’t use project specific libs. If I want to reuse a symbol, you may have to hunt for it.

Make your own private lib. Place all modified symbols in that lib. Each symbol MUST HAVE A UNIQUE NAME. When you use that symbol in a future design, you’ll know where to find it and can preview it before placement.

#4

Symbols can have the same name if they are in separate libraries.
I decided to have the same name at schematic for 1k 0402, 1k 0603 and 1k 0805. All they are 1k at schematic. To get this I have 3 separate libraries for resistors. I use libraries with footprint assigned - I skip the stage of assigning them at schematic.

Using my solution you will have the same symbol but it is hard how to logically name the libraries :slight_smile: