Hallo
I made a schematic and wanted to create a BOM for counting the number of electronic parts I used in my project so I created a BOM. In the BOM I realized that the same Part (Ferrit BEAD ->FB1) is listet more than one time.
When I looked for an reason I realized that for every additional field entry there was made a new Ferritbead.
The folloing picture shows the symbol Properties (including additional field entries) which are shown in the symbol editor? Can anybody tell me why this happens?
Do not forget to change the extension to “'CSV”, maybe you have two outputs, one “blahbla.csv” and another one without extension “blahblah” and you keep opening the one that hasn’t been modified.
The first and last error might be quite dangerous. You have the same pin number on multiple units of U3 (not a good idea! Every pin should be only once in the symbol).
If you then connect it to something different on different instances (Example you have it connected to GND for unit A and V_INT_SARA on unit B) then kicad can not really say what to do.
I changed it to input and now it works fine! But I had to add a Powerflag. When I tested using a powerflag and changed it back to an output (I know it is an input actual) there still was a ERC mistake. I always thougt a powerflag always solves the input/output problem? Or did I missunderstand this?
The power flag is intended for exactly one usecase. KiCads ERC is net based. There is one check where it looks for every power input pin if the net that the pin is connected to also has a power output pin. (This is a simplified version of a check to ensure every device is powered.)
That check has some limitations. Lets imagine you have a passive device between the power source and your power consumers. KiCads net based ERC does not understand that power is transferred freely over it. Meaning you somehow need to tell kicad that yes this other device is now where power comes from. The solution is to place the power flag at the “output” pin of the passive to tell ERC that the net this pin is connected to is indeed powered.
The second usecase is that you will most likely use some form of connector as your main power supply. If you want to use a generic connector symbol then you will need to connect a power flag to it such that ERC knows that yes this connector is where power comes from.
A major thing to remember is that every net is only allowed one power source at the time. This includes power flags. So if all your gnds are connected then you only need one power flag right next to the main power supply connector.
