Suspected errors in Kicads libraries

Schematic Library Symbols
1

Hi,
I think I’ve found an error in one of the PIC measurements. The kicad version of 18LF2520 is 8mm total pin to pin width, and the actual pic size is 10mm pin to pin. Is there a correction for this, or do I need to make my own version of the PIC?
Camerart.

2

Hi Camerart

The 18LF2520 isn’t in the standard KiCad PIC 18 library - did you make your own symbol?

What footprint is specified in the symbol you’re using?

And can you confirm which version of the chip you’re using ( e.g. DIP, SOIC, etc)?

Regards

Ray

3

Hi R,
In the data sheet, it shows SOIC, so I chose the SOIC footprint. (I would post and image of the measurements in the data sheet, but can’t find the attachment button) The measurements are: E1 7.5mm E (Overall pin width10.3mm I made the PCB, and found the PIC is too wide.
I tried modifying the narrow footprint on the editor, but it showed read only when I came to save it.
C.

4

Which KiCad footprint did you use? What’s the name of the .kicad_mod file?

Is this the datasheet you are looking at?

666×714 70.9 KB

This is the KiCad footprint that matches it:

895×665 4.75 KB

2 Likes
5

Hi R,
I have the data sheet ok, same measurements. I now notice WIDE at the top.

Footprint: SMD_PACKAGES------SOIC-28
C.

6

Hi again R,
Yes, that’s the one. I don’t have it in my libraries, and as mentioned is shows READ ONLY.
C.

7

The best place to look for SOIC footprints is in Housings_SOIC.pretty. That’s where I got the footprint that I screenshot above.

1 Like
8

There are two things here.

To get the full set of latest footprint folders, there is a script called download_pretty_libs.py that is available here: https://github.com/KiCad/kicad-library-utils I’m sure I have seen recent posts on this forum about how to use it - I will have a look.

EDIT: What version of KiCad are you using?

Second, if you want to modify a footprint to suit your own purpose, it is better to copy it and create a new footprint in a folder that you own and have write privileges to.

1 Like
9

Hi R,
Found the footprint, thanks.

Kicad 4.0.2 was completely new last week, so i presume it’s up to date.

Thanks for you for you prompt assistance, you probably saved a big tangle.

Cheers, C.

10

4.0.2 hasn’t been new for a long time, the latest stable release is 4.0.6. What you get with that depends on your OS and how KiCad was packaged. The Windows version has a snapshot of component libraries and 3d models, but by default footprints are downloaded as needed from latest github.

1 Like
11

A bit more details for the information by @bobc

But the list of libraries is not updated. For that you need to start the footprint wizard and move through it. (On the first page select github and decide if you want the libs online or offline.)
If you want offline libs, @bobc has a good tutorial on his github page:

1 Like
12

Hi B and R,
I wonder why I wasn’t offered 4.0.6 when I downloaded it? I thought I went to the main site, and took the top of the list.

I went through all of this a few weeks ago, when I messed up my computer, and had forgotten it. i did however manage to get 4.0.2 going with all of the libraries somehow. It isn’t an easy system to remember everything, but I accept this, and will keep using it.

I have 4.0.2, and not a good wifi, so I go elsewhere to download large files. Do I need to change to 4.0.6, or should i leave well alone, as it’s all working ok for me?
Regards, C.