@kenyapcomau : yes, I was exploring the libraries, and playing around with symbols and footprints pin #, and ratsnests.
@EI9HEB : stacking makes symbols difficult to read and edit. Not a great fan either.
I don’t really understand why the KiCad library comes with duplicated pins for switches (and also for many transistors), and with stacked pins for many DC to DC converters (for example : Converter_DCDC library) ; . It seems PCBnew behaves the same whatever is the method, but drawing schematics with stacked pins should be a lot easier for ICs with lots of power pins.
Some symbols also show separate GND pins, with different pin #. For example the ADuM5404 (in Isolator library) has two separate GND1 pins, and the ADuM5410 has two stacked GND1…
Thre’s probably a reason ; could stacking be the modern way of designing ?
Still hesitating before sharing symbols footprints and 3D models on Github… But the law says : “Power supply pins must be stacked unless the datasheet specifies the need for decoupling capacitors on every pin”
First of all what I’ve described is not pin stacking. That’s a different technique where pins are laid on top of each other in the symbol. What I have described is just giving the same ID to more than one pin.
If you look at the SPST switch case, it makes sense. Electrically it’s a SPST switch, but it has 4 pins. If I had to look for a footprint it would be a SPST symbol but one with a 4 pin footprint. If each pin had a distinct ID you might end up routing different nets to what are equivalent pins and shorting something.
But not all symbols or pins use this technique.
Edit: It’s probably moot what technique you choose to use for your footprint of this module, just suit yourself. With this sort of module there are no official dimensions. Another brand or batch might have different dimensions. So somebody’s footprint might or might not suit you. By the same token if you share your footprint others have to verify against what they have.
When a user downloads a library, the lib is verified. One year ago, I shared BluePill and Black Pill models for KiCad. The BluePill had a mistake. It was spotted by a user (https://grabcad.com/library/stm32-bluepill-2) . A 5 mil error on the 3D model, not the footprint. This means that users verify and adapt for their own use what can be found on the web. And this is great. Currently 17 very common chinese modules are ready for uploading (including this LM2596 one).
Look forward to seeing your contributions then. Fortunately the Chinese tend to stick with a few designs for a long time so it’s likely a footprint will stay valid over a period.
You will notice that the capacitors top faces are concave, not flat or convex. This means that the caps are in good shape and will not need any replacement. The module is brand new.
[EDIT] there was a mistake in the footprint (after playing with pin numbering…). It was fixed and files reuploaded, but it takes ages for the servers to update their cache. So, better wait a bit before downloading. And after half an hour, GrabCad still does not display 3D previews.