PCBNew does not autorute in the same logic as laid in the schematic

Layout
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I have laid a circuit with a power supply, some decoupling capacitors…to form a radio controlled relay:

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Well, the thing is that after manually arranging my components, and autorouting in PCBNew, my connections do not follow the same logic/order than laid in my schematic! So, if I had thre components A, B, and C; and I needed electrons to go from A to B and finally to C; PCBNew will be indifferent about that, and would just connect A to C jumping B, just because A and C are closer to each other than to B.

To come with a tangible example (I am not allowed to also show you the picture with the PCB layout): After autorouting, I get the “V+” pin of the “IRM-3.3” directly into “ATtiny85” pinc “Vcc”, when in reality it needs to be decoupled through capacitors “C3” and “C4”.

Yes, I am a huge noobs. But thanks for reading this :slight_smile:

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It looks like C3 and C4 are connected properly in the schematic. When they are connected, the small square boxes go away.

1 Like
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So you mean they are not connected propperly?

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Sorry, I missed a word :slight_smile: It looks like C3 and C4 are NOT connected properly in the schematic. They might be ok, but the small boxes usually indicate a missed connection.

However, the autorouter is quite dumb, it does not know about decoupling caps etc. If you need a particular layout, either put some tracks in by hand first, or fix them after the autorouter has run.

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Thanks Bobc! I’ll give it a shot by hand. Well, I do not want to imagine how tedious this must be for bigger circuits!!

Cheers

/Ivan

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That’s why people usually keep to a certain style to make reading/checking of a schematic easier…

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