BOM entries unintentionally grouped

I’ve upgraded to LibrePCB 1.0.0, and there is an odd thing. Here is an entry in my BOM:


The U components and the ZD components have been put on the same line. These are separate components, but they do use the same package (SOIC-8). Before the upgrade these were on separate lines in the BOM.
I’ve re-scanned the libraries a couple of times, but it is still the same.
Here are the two devices in the library editor:

Any ideas what is going on?

What value have these components set in the schematic? And could you post the complete BOM here?

Note that the grouping does not consider the underlying library element or the prefix (U vs. ZD). Only the BOM data from the third and following columns is considered. If their content is the same (e.g. empty), they will be grouped.

I figured it out!
The BOM from the previous version included a column for Device. I found a spot in the user manual that tells me how to add that as a column, I need to put “DEVICE” in as an Attribute, like this:

You can do that, but the device column has been removed from the BOM because the new MPN column is much more accurate. So generally it’s recommended to set the MPN for those components, this will also fix the BOM grouping. Or instead of the MPN, the Value could be set instead. For most library elements, it is by default set to {{MPN or DEVICE or COMPONENT}} so if no MPN is set, it should actually be equal to your DEVICE column.

Maybe your components in the library don’t have a Default Value set? With the default value set to {{MPN or DEVICE or COMPONENT}} your BOM should be grouped correctly I guess.

Ok, no, I don’t have the Default Values set.
In the documentation (following your link) it says “If you are unsure, just leave it empty”, and that is what I did.

This project was created in the previous version. I’ll have a look at MPN (Manufacturer Part Number, for anyone following along!) and perhaps use that.


By the way, in Ubuntu Linux (XFCE) the BOM dialogue box overrides everything else. So if I get up a BOM window, I can’t go over to the PCB Editor, or Library Editor. A bit annoying when I’m trying to see how a variation in something has affected the BOM.

If you are unsure, just leave it empty, the component editor will help you to assign a value later. :wink: in fact, the component editor shows a warning if the default value is not set.

This is by intention, because the BOM content is not updated automatically when you make a change in the project. So it’s better to “lock” the project while the BOM dialog is open. But of course for long term it would be better to allow making modifications while the BOM dialog is open and update it automatically.