I am using tactile switches for my PCB, and I found two possibilities that match the size I have (7.62/5.08mm pin distance). See the blue box upper right in the picture below. There are two versions, but I do not know which to chose, they look exactly equal, and I don’t see any different property. Is there any difference, and if so, what differences?
My next question is about the footprint. In the footprint viewer (left bottom picture), there are two pins numbered one, and two pins numbered two. This is because internally these pins are connected. However. In Pcbnew, I have to add the red wires (see the blue ovals in the bottom middle). If I remove them, I get unrouted nodes. How can I get rid of those mandatory (and unneeded) traces?
You can open the footprint directly from the board to the footprint editor or just open individual pad’s properties dialog and remove the pad number from the pads you don’t want to connect.
That works partly … I can remove the pads, however, the ‘hole’ / foot of the switch will also be gone, so I cannot solder the (unconnected) legs of the switch in the PCB.
If you don’t see any relevant difference, then there is no difference. Looking into the datasheet (I found one in http://pdf1.alldatasheet.com/datasheet-pdf/view/163910/ITT/KSL0A211LFT.html) there’s no difference either. There are no 3d models for them so you can’t see the actuator height which is the only difference.
I found it … it doesn’t matter if the number is removed or not, but what I changed is in the pad properties, setting Net name to : . Than I can remove the red trace, and no error shows up … THanks for leading me in the good direction.
It looks like you have to update the board from the schematic after removing the pad numbers to get rid of the complaints. But if you remove the net name from the pad it will be added back when you update. So removing the number is the way to go; you just have to update the board from the schematic.
There’s also another option: use a symbol with pins 1…4 and change the footprint pad numbers so that they are 1…4, then leave some symbol pins unconnected. I have abused this strategy to get an extra electrical connection in a tightly packed board so that I got kind of a jump wire for free. But it’s easier for you to just remove the two pad numbers.
You could add two internal layers to your design and connect the pins across one of the two internal layers. Then when exporting to Gerber, only export the top and bottom layers. Only use the board internal layers for connections that are internal to the parts.
Just don’t forget about using that kluge when you export the board or you may accidentally pay for more layers than you need. Because of that risk, I wouldn’t advise doing this, but it is a possibility.
… THanks for leading me in the good direction.