I am using kiCad to create my schematic. Is it conventional to connect all unused pins of an arduino microcontroller to something? I performed an electrical rules check and it gave me all the pins that weren't connected so I wondering if I have to in order to create the PCB.
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Unused pins : what to do with them - Arduino Forum
](Unused pins : what to do with them ?)
You can note on schematic or reflect in the schematic.
Ron
@nclegend28
Because you did not use the no-connect flag?
If use it you won't get the errors
That may be because you must have pads on the circuit board to solder the IC pins to. Probably the program will not create the circuit board pads if not specified in the schematic.
Everything must be connected to something, even if the something is the NO Connect symbol.
From a circuit point of view, outputs can be left unconnected (using the no connect symbol). Inputs if open should have the internal pull up enabled (and the no connect symbol). The reason for the pullup is; digital IC's don't like inputs "floating" where they could be an the voltage between 1 and 0. This can cause extra current draw and maybe damage to the processor.
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Ok. Thank you so much.
I have another question. On the arduino nano, there are two grounds. When running the ERC i get the error message "input power pin not driven by any output power pins" for both pins. I don't understand why it can't be connected to the GND symbol.
There's no pin defined as a Power output type on that net (KiCad doesn't know that the two ground pins are connected). Since you already have a PWR_FLAG on the other ground pin (which is a promise to KiCad "yes, although you can't see it, there really is something providing power on that net"), connect the two ground pins together.
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