[SOLVED] Why does newPcb mix up pin header power supply nets?

Hi. Can I please ask question? Why did newPcb mix up power supply nets and connected +9V to GND?

This shouldn’t connect. Notice how pin 1 connects pin 2 of the pin header in PCB layout:


It doesn’t connect in the schematic (see sbove). Then why did NewPCB mix up those signals?

First run ERC check in eeschema. Is everything OK? Presumably you used Tools->Update PCB from shcematic, right?

Your are connecting many nets together with IC2, wherever the junction dot is placed (the green circle) the lines passing through are connected. also in IC1A, both pins of the SchmittTrigger (??) are connected.

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I did, everything looked allright. It complained first about one pin not being driven, but that was solved by adding power flag to the +9V supply net.

That is correct. I am using this schematic: https://www.belza.cz/toys/dice.htm

Oh, I saw it now. For some reason KiCad thought I want to connect all those pins together when I ran wire through them. I have to somehow make sure that the wire doesn’t touch the pin lead. Thanks for fair warning then :slight_smile:

Of course it does. How could you NOT have a wire touching a pin end be a connection?

Also, it is good practice to avoid making 4-way junctions like that, where you need a dot to indicate if crossing wires are connected or not.

Even long before using KiCad I got into the habit of running schematic wires perpendicular to pins one grid point away from the pin ends. Some schematic software are really grabby and will connect any pins touching wires, even without junction dots. Other schematic software will only connect wires parallel to the pin forcing at least a 1 grid long wire to connect to a pin even if you want the wire routed perpendicular to the pin to get to the next pin in the net.

IAFAIR, KiCad is the grabby type, especially now with the automatic junction dots (though the automatic junction dots make this behavior easy to see unless you set the junction dot size to the drawing width of the lines to hide them).

Keeping perpendicular runs one grid point away from pins will help you from accidentally running into random behavior across schematic capture programs.

:smirk: