I’m quite new to KiCad but I made a project of doing a homemade Arduino SD shield for different applications. My scheme seems right so I moved on to the PCB design. Everything was going well until I stumbled upon a problem I can’t solve on my own (I’ve been doing research for 2 days).I was wiring everything and I was going to make my ground equipotential area. But when I clicked on “add an area”, GND doesn’t show up in the netlist. As I’m new to KiCad, I don’t even know how KiCad automatically detects those equipotentials (I have a very looong list of all my SD pins, Arduino pins etc… but no GND! Which is the only one I really need).
Hard to answer without any design data but my guess would be that you never defined GND in the schematic as dedicated net. Usually this is done by using the GND symbol from the power library which acts as a global label for the whole project. Connecting all dedicated GND pins of different symbols to one or multiple of these GND symbols wont just connect all these pins together in the layout, it will also name the net GND to find it easier in the layouts tools.
Yeah sorry maybe I should’ve shared a screenshot of my project. But I actually used the GND from this power symbols tool :
as you can see in part of the schematic here :
(sorry I’m a new user so I can’t share 2 images per post - I’ll leave the second screenshot down on the second post)
You screenshot isn’t really clear, but it looks like you connected GND to +9V (middle left side in your screenshot, above the SD card). In that case, KiCad has no idea what to do, the combined net probably gets randomly named either GND or +9V.
Okay I’m going to remove that but this was just a test I was doing, following instructions I found online on another forum so the problem doesn’t come from there. But indeed maybe I confused Kicad on another part of the scheme, I’m gonna check that and if I don’t find anything, I’ll share the whole scheme here!
I hope you meant “add a filled zone” either from Place > or from the right hand side tool column. It then prompts you to start drawing a boundary, and also presents you with choices of nets to assign to it on the copper layers. If GND doesn’t appear on the list, then you have to check if you really do have a net called GND.
Yes my Kicad isn’t in english that’s why I was confusing. As you say, GND doesn’t appear on the list, and it doesn’t appear in the net visuals neither
It appears nowhere actually, even in the netlist inspection
If the project is not sensitive, best you zip up the project and upload it. I’m sure somebody can spot the problem by looking at your design. You may have to wait for a moderator to promote you or read more posts to accumulate points towards the next level.
Here’s a screenshot of the complete scheme. It’s not the file as I can’t upload it and not the best quality but if there’s an error with the scheme, it’s visible there and I seem to have a hard time finding out that error.
You’re right thank you I changed them for the GND symbol.
But I don’t think it solves the problem. I updated the PCB and GND still doesn’t show up.
I have 4 errors in the PCB update (pad 10,11,12,13 not found but they aren’t connected so not a problem)
And 28 errors in the electrical rules test. They’re mainly coming from the fact that 2 of my op amps aren’t powered (I don’t know why I don’t have the possibility to connect them to my symmetric power supply like on the left one) and errors I don’t understand such as arrows pointing at random areas and error messages that don’t have any sense.
what happens if you use the Highlight wires of pins of a net function on one of your GND lines? in the schematic as well as in the layout. do all pins connected to your ground start glowing and also maybe others? what net name have the now also glowing pads in the layout?
Basically this means that you have connected your A10 net with the GND net. If this is intentional only you know but if it is (it seems like from the schematic) I would suggest to remove the A10 net and directly connect the affected pins to GND instead.
Looking at the datasheet of the ADG406BN (as squinted from your schematic, you owe me a pair of spectacles), the D (drain) pin is the common input or output of the multiplexer. So either you are feeding A10 as input of the Arduino with it, or you are distributing A10 as output to it. Either way it does not make sense to ground this net.
What probably happened is that nets can only have one name, and A10 won over GND.
I am calculating the resistance between two SD pins with a voltage divider Rc1 and Rpin… So I cannot take the GND off this place!
But thanks for the answers it makes more sense now!
Yep, but there is actually a resistance created between these two wires I tested everything on a breadboard before designing a PCB…
So what are my solutions here ? Can I make KiCad understand that my A10 isn’t truly grounded ?
And I’m starting to wonder if I really need to ground my wire here because my +3.3V coming from digital pin 22 is referenced with the same GND so it could maybe work without this GND
