What am I doing wrong in Eeschema?


@Rene - so I’ve now included a third unit for power only and superimposed it over the first unit and connected it all up and now have the following:

So I connected the grounds together and defined the GND pin as a Power Output and got the following:

Success! So the GND Pin needs to be a Power Output, right?



which gnd did you define as power out? I hope not the one of U1!
Place a power flag near on the gound net near where you connect ground to your external power source. (Most likely a connector)

Do it this way to ensure that ERC can detect if you have connected the ground pins of your symbol to where you get power into the PCB


@Gozzle: I hope you not ignoring my response. I were telling you to add PWR_FLAG for the GND. And should not try to use Power Output type for any symbol as much as you can.


GND is a PWR_FLAG according to my KiCad. Or which PWR_FLAG do you mean?


there is a symbol called PWR_FLAG.

It is in the same library as the GND symbol but it is for a very different purpose.

The PWR_FLAG symbol has a single pin defined as power output. It is intended to mark the place where you supply power. (The connector where you connect to your external power supply, after a passive device in the supply line like a fuse, …)

The GND symbol has a single hidden power input pin. Such a pin is a global label (yes this is hacky). Such a symbol is called a power port or power symbol.

More details see: ErrType(3): Pin connected to some others pins but no pin to drive it


Please go down to section #43, or search for “PWR_FLAG” in following page:


I don’t like the way they use it in this tutorial. By connecting the power flag directly to a power symbol you loose the reason to have it. I would suggest to place the pwr_flag symbol as near as possible to the place where the board is supplied.



I’ve got a three module LM556 and the Vcc and GND pins are “Power Input” pins. I flagged the GND input pin to my board as a PWR_FLAG and it all works!

Thanks to you all for your patience with me. I’ve learned so much about KiCad just because of this one single problem.

Time for bed…



A PWR_FLAG is virtual schematic element with the pin set to Power Output.

How many different ways can a multi-pin connector have power applied to the PCB from the Outside World?