Connection Error

It’s a link to a faq, look at the post tag

here for all you people that think that you’re God’s gift to creation, I still practically get the same error

You wouldn’t if you had listened to all those people.

Below the relevant section from the FAQ article already posted above: ErrType(3): Pin connected to some others pins but no pin to drive it

it wasn’t helpful the first 2 times I read it either.

How do I delete my account?

Ok lets put it differently:

KiCads ERC is kind of basic. It checks pins on any given net against each other. One of these checks is to see if everything is powered. That check works by testing if every net that has a power input on it also has a power output on it.

Normal power symbols (like GND) are power inputs. So are all power supply pins of ICs (if they follow the library convention). This means any net with something like this on it needs a power output.

For this reason there is a special symbol called the PWR_FLAG. This symbol is simply a symbol with a single power output pin. It has little in common with normal power symbols other than being in the same library and looking kind of similar (it does not create connections). To see how that symbol looks like check the screenshots in the FAQ article. For examples of how to use it again see the article.

Also remember ERC is just a tool that should point you to possible errors. It is totally ok for you to decide not to use it or to ignore certain error messages. (However, sadly there is no option to tell kicad not to show a certain error again, at least not in v5)

It is often unwise to be hasty about such decisions :wink:


Aside from the ERC, SW1 doesn’t make sense to me, it bridges +12V and +12V, unless it’s being used for just the LED.

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Your patience is amazing.

Now I remember why I used to avoid forums. Just puts me in a bad mood.

Maybe there is a lack of knowledge about power symbols in general.

@bckelley TlDr: power symbols are there to make connections without drawing a wire. I explain their use in this tutorial (second part of it) Tutorial: Introduction to PCB design with KiCad version 5.1 (Getting Started)

Think about how I feel! Trying to learn something new, I’m completely lost frustrated and completely pissed off!

It often helps to take a break :wink: (Get a coffee, tea, beer, … but most importantly step away from the computer for at least half an hour. Believe me it helps massively.)

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yea it does I assumed that’s how you did it

You were basically spoon fed by several people, within minutes of asking your question.
Yet you chose to ignore all the instructions to add PWR_FLAGs.

What exactly do you expect?

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What @kenyapcomau tried to convey is that the two power symbols (the two marked as +12V) currently create a short circuit over your switch. This means your switch right now will never be able to turn this circuit off. (use the highlight net tool on one of the wires near a +12V symbol to see what is directly connected to each other)

Sorry, I forgot to comment on this. My optional suggestion for a PWR_FLAG symbol on the output is because I suspect that you will want to use that +5V somewhere. So somewhere else on the circuit you may eventually connect an IC to the +5V. If either: the output pin of U1 isn’t a Power Output type pin (part of the symbol definition, you can check this in the symbol editor), or you don’t have a PWR_FLAG symbol on the +5V net then you will get another error like the first three that you reported.

It was an optional suggestion, and may be a little more advanced for your current skill level. My apologies if I muddied the waters by including it.

Well to be honest my patience is already quite low compared to lets say a year or two ago.

This is the reason why my first post was just a link to the FAQ, and also why my second one was a reminder to read the FAQ (in the past i would have included a bit of an TlDr as well but i simply don’t care enough any more.)

This might be part of the problem. Getting too many answers in such a short time might be too much to take in properly.

I am extremely hesitant to involve myself in this discussion… but… from his actions, regarding the previous suggestions, I suspect that @bckelly has no idea of the concept of a “power flag” and that it is unique and different from a “power symbol” (hence his assigning the 12V “symbol” to both sides of the switch after the suggestion that he needed a “power flag” on both sides of the switch.

Considering you wrote the FAQ for exactly this situation… :wink:
I think the community has been quite patient and helpful to this individual. I’m sure the mods appreciate that this didn’t go ‘way south’.

While reading this thread I got the same Idea as KingJL.

I assume bckelly is is mixing up “power symbol” and PWR_FLAG.
So I made a screenshot:

These different schematic symbols are pretty important in KiCad, and you won’t satisfy the ERC checker without also adding the “PWR_FLAG” symbols next to the “Power Symbols” in your schematic.

For more details, read the articles from the links provided earlier.


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