Sorry, a newbie question…
I’m getting this ERC on global power (input) signals inside hierarchical sheets.
The signal (PGND) is a power ground, and connected to the global ground signal via a resistor on the parent sheet.
Interestingly, there are no markers on the two instances of the PGND on the parent sheet.
What should I do to supress this error?
And more generally, must there be one (and only one) component on a power net that is a power output? What’s the recommended way to do that without having a custom symbol that is the one “source” of the power net?
Lot more in that post than the specific question I raise.
Here’s the one sentence I needed:
KiCad has a rather unique tool to solve these ERC issues between symbols. KiCad’s creative solution is the PWR_FLAG! (The PWR_FLAG is found in the power library supplied with kicad. Use the “place power port” dialog and type PWR_FLAG into the search field. Place it like any other power symbol.)
But, I don’t understand why I didn’t get this error for the other global ground symbot–I don’t think any symbol connects to it via a “power output” pin. I’ll check more carefully to be sure.
Thanks!
You get any ERC error exactly once per net.
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Yes, but I got no 0 for the GND net. It is a different net (or at least it is supposed to be!) than the PGND net. They are connected by a 10 ohm resistor.
Yet, the errors are eliminated when I put a PWR_FLAG on a net segment that’s connected to a connector.
This suggests somewhere there is a short between PGND and GND?
Meant to say I got 0 error for the GND net, just the PGND.
Or you have anything on the GND net that supplies it with a power output pin. Or the error is shown on some other pin than the GND symbol.
I said that poorly…
When I add a PWR_FLAG to a net on GND, the errors on PGND disappear. I guess that’s because PGND is “driven” through the 10 ohm resistor.
But, I would expect all pins connected to the GND net would have the error when the PWR_FLAG isn’t on the net. But, just the PGND has it.
Yeah, I"m looking for that. But, if that was the case, I would not get the errors on the PGND when the PWR_FLAG is not there.
Use the highlight net tool to see if the two nets are connected.
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Yes, the highlight net tool says they are connected! But I sure can’t find the connection.
Still looking…
Did you make one of the power symbols yourself? Are you aware that they work by having an invisible power input pin whose pin name is responsible for defining the net name? Tutorial: How to make a symbol (KiCad v5.1.x) section “Creating a custom power port (power symbol or power label)”
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No, I did not make myself.
Yes, I’m aware of the invisible power pin input.
But, now that you mention it… I did import a schematic from Eagle. I thought I switched all the GND symbols to Kicad flavor, but maybe there’s an instance on one that’s identical looking that’s actually different. Checking that now.
Eagle import places global labels as it can not import power symbols so maybe there is one such label left (they are rather small so easy to miss)
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Ok, looking for that.
I do have the Eagle grounds, but they are power input. Probably best to just replace all the Eagle ground signals. I haven’t learned how to do the equivalent of Eagle’s “replace component”, so I’ll figure that out and replace them all.
You can use the “edit symbol library references” dialog that is found in the tool menu.
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Perfect! But, I can’t edit that, can I?
Edited it–looks exactly the same. But, that fixed it!
Not so fast–just fixed it because it disconnected the GND signal when I did that.
Still searching
So, the two GND symbols I’m using (from KiCad) are GND and GNDPWR. I’m assuming the corresponding global nets are GND, and GNDPWR. NOT net GND for both, right?