If you have a design that has off board components, ( switches that are panel mount connected by a wire harness for instance) what footprint do you assign to that switch, or do you just leave it blank and ignore the error?
Iām breaking protocol by posting before introducing myself, and I apologize for that. Iāll get around to it eventuallyā¦
Iāve often run into your situation, whether itās a daughterboard, an off-board component, or non-schematic items that I want on the BOM. The answer to the first two is that the component connects to your board somehow, right? However it connects is the footprint. If itās two wires from a switch, then make a footprint consisting of the two pads those wires land on. For non-schematic things like an external PSU, I create a symbol consisting of a rectangle without pins and stick it in a corner of the schematic somewhere, with its properties set appropriately.
Julia
2 Likes
Hi Julia,
After the Amp Hour interview, no introduction needed :-). And thanks for taking the time to respond. Do people manage cable harnessing in KiCad? Or is there a better way to do it?
ā
Guy
1 Like
Try this: https://forum.kicad.info/t/components-off-pcb/14707
Iāve not tried to see if the component shows up in the BOM or other effects. The thread then wanders off topic.
This may be unpopular, but Iām of the opinion that those off-board parts donāt belong on the schematic at all. The reason is complicated, but the simplified reason is the schematic drawing isnāt the āproperā place to collect parts for your BOM - that would be on the assembly drawing.
Having said that, I agree, for a single board prototype with no significant off-board stuff, shoe-horning those parts on the schematic makes sense. I would do that too if necessary. Just be aware thatās not āhow itās doneā in the industry (Iām open to correction, since itās been some years since Iāve made a large technical data package).
I wish I lived near Chicago and Chrisā KiCon, because Iād really like to make a detailed presentation and/course on engineering drawing practices some day.
Thereās āthe right wayā as rclott hinted. At the systems level, the panel-mount switch + cable assembly may stand on its own at an equal level on the assembly hierarchy as the PCBA. Or, it could be that the switch is mounted to the panel as part of the panel subassemby, and the PCBA is is joined to the panel (with the switch mounted)ā¦ (Or the switch/cable assembly is attached to the PCBA first, tested, and then later the whole setup is mounted to the enclosureā¦)
As a practical matter, since I do most of my design in ECAD (I use Altium myself, but it doesnāt matter), I usually just use a separate schematic sheet to capture the āmiscellaneousā items. It might have to sit in its own project (depends on your softwareās ability to cleanly exclude the items from being part of the netlist on the PCB), but itās easier for me to just stay in my ECAD software than to have to separately manage the non-electronic stuff in a different environment.
It also has to do with how the different parts are managed ā if youāre a bigger established company with supply management solutions, you have to be more formal about splitting your design along separately orderable pieces. For a solo or smaller shop, thatās just excess workā¦
1 Like
I know this is an old post, but did you ever get around to doing some kind of presentation or course? Iām starting to think about some of these issues and Iād like to learn how to do it the āproperā way.