I’m learning KiCad now (from Eagle free and DIpTrace) and the project I picked wasn’t an easy one. I’m recreating the processor board from an audio project. In it, there are 6 tactile switches for the front panel which provide 2 locations per switch to account for two different face plate designs.
I’m trying to figure out the best way to do this. Adding 6 more switches to the schematic is off the table.
The physical layout has two of the pads (SMD) of one switch footprint overlaying two pads of the other switch perfectly. It occurred to me that I could do a custom footprint for this, with two extra pads. I would also want to add connections between pads to the footprint so I don’t have to route these manually on the board.
Any thoughts on how to do this? The board I am recreating was originally done in KiCad, but the author doesn’t want to share the files, etc. over a fear of the project appearing on aliexpress, etc., which I can certainly respect. I picked this board to recreate because it is challenging and figured it would expose me to a bunch of esoteric issues in learning this.
I have built the project in real life and do have a blank board to help with measurements, etc. Thanks for any help or thoughts!
I hereby certify that I am not simply asking someone else to design a footprint for me.
This is an auto-generated message that is in place on the “footprints” section of the KiCad.info forum. If I remove it and ask for a footprint to be designed anyway, I understand that I will be subject to forum members telling me to go design my own footprint or referring me to a 3rd party footprint site.
I don’t know how you are going to do it . . . I know how I would do it. I’d add an additional 6 switches to the Schematic, use KiVar to make 2 variants and with a little bit of layout work I’d be done. No BOM issues, two clear schematics dependant on variant and documentation aided by JPGs showing the 3D of the two variants.
Out of interest, why is adding 6 more switches to the schematic not an option for you ?
I wasn’t aware of the KiVar capability, but it seems like kind of a kludge. It is the same switch, just two different mounting positions. The switch is a Bourns 1301.9319.24. I got the schematic symbol and package from UltraLibrarian. My goal is to duplicate the original schematic and pcb identically (as possible).
Here is a screenshot of one of the switches in the original schematic:
This is a picture of the board area for one of the switches:
And this is a picture of the original part footprint:
I would like to superimpose another footprint onto this, with I guess another set of pads 1 and 2 below. Both sets of pads 1 & 2 would connect to the debounce network; 3 & 4 to DGND.
The original was done in KiCad eeschema (07-07-2013 BZR 4022) -stable.
Mak a new footprint. Just takes a couple of minutes. Here I selected a pb called S_pushbutton4pin_vert_B_smt, right-click Duplicate-Footprint, called it S_pushbutton4pin_vert_B_smt_FUNKY_VERSION. Then selected the measure tool to determine pitch between the pads vertically (the tool will snap to a pad corner, which is frickin cool) – so I need to plunck new pads down 4mm below the lower pads. If it was an oddball number I would edit the User-Grid size, but it is easy enough to just set the grid to 1mm.
Yeah, that is more work than just routing, and you have full flexibility at route time and are not constrained by static footprint copper. And traces or lines don’t work in a footprint – you need to overlap a bunch of smd pads (with soldermask enabled) and numbered appropriately… I have only done a few footprints like these:
It’s a bit unkind to call it a kludge . . . its a External Plugin that adds functionality to KiCad that is not native.
If you use a single footprint with both positions how will you document this for production purposes ? You will only have one BOM so only one component reference regardless of the variant . . . you will only have one schematic, how will you specify which location the switch goes to ?
I wasn’t calling KiVar a kludge as it seems it could be a very useful capability, but its use for this particular problem seemed so. And thanks for calling it out as I was not aware that this was available.
This isn’t a production board; the builder would choose which position to mount the 6 switches in based on what faceplate design they were going to use.
