Hi.
Obviously I’m a newbie.
I have inserted in my diagram a switch on a power line.
I connected it intuitively.
But the resulting pcb is not what I expect.
I was expecting two lines in on the switch and two lines out.
For simplicity I have extracted the problem in a simple project.
What mistake did I make?
Many thanks
Probably the footprint have pads numbered “1”, “1”, “2”, “2” instead of 1…4
there is no mistake, just a capturing oversight
A schematic is an abstract representation of a physical circuit. In this instance it would appear that while you selected a 4pin schematic symbol, the actual footprint you chose is a 2pin only
you have not shown the footprint you are using but it appears to be a SW_PUSH-12mm
As you can see, while it is a 4pin part, it only has 2 pin numbers. Thus the cct symbol’s 3 & 4 will not be mapped. There should have been an error message when you imported the netlist along the lines of missing pins 3 and 4.
How to correct
- down-select the actual switch you want to use (ie the part you will buy)
- double-check footprint
- if this is the correct footprint, save it as part of your local library and re-number the pins
Hi fed4U, Naib
But I have selected a standard footprint:
Do I have to change it?
depends. That “standard footprint” might be valid for a type of STSP but might not be for the type you are after.
What exact part are you looking at buying? there maybe a more valid footprint in the library or it could be made trivially.
In short you do need a different footprint, which might involve copy-edit or a full redraw
Your selected footprint is based on the TACT switch:
These are wired the way the footprint is designed.
So basically, for a double switch you’ve picked wrong footprint.
I’ve used hundreds of these of many brands and ALL I’ve used are the same. Two pins on each side are Internally connected.
Grab some parts and DMM and test for yourself.
Sometimes I physically hook up tracks to all four pins but mostly I don’t bother as each side is already internally connected.
Thank to BlackCoffee, fread4u, Naib.
I follow fred4u’s suggestion. Until I gain a lot of experience I accept the easier advice to follow.
Thanks again everyone. 
The 6x6mm tact switches are a very common part indeed, made by many manufacturers:
https://duckduckgo.com/?q=tact+switche+6x6&t=h_&iax=images&ia=images
However, @rmoggia uses a dual switch, while the 6x6mm switches only have one switch, so be careful to verify your schematic symbol with your footprint and the layout of the actual switch.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.